GUIDELINES FOR INDOOR AIR HYGIENE IN SCHOOL BUILDINGS · In the 2000 “Guidelines for Indoor Air Hygiene in School Buildings” the Federal Environment Agency drew attention to hygiene

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GUIDELINES FOR INDOOR AIR HYGIENE IN SCHOOL BUILDINGS

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Contact: Federal Environment AgencyPostfach 140606813 Dessau-RoßlauInternet: www.umweltbundesamt.de E-mail: [email protected] Printed on 100% recycled paper

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Published by:Federal Environment Agency (UBA)Innenraumlufthygiene-Kommission des Umweltbundesamtes

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© 2008 Umweltbundesamt Berlin

Guidelines for Indoor Air Hygiene in School Buildings

Produced by the German Federal Environment Agency’s Indoor Air Hygiene Commission

Berlin, August 2008

10.140_UBA_Schule_engl_04_RZ.indd 1 22.03.11 09:45

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Guidelines for Indoor Hygiene in School Buildings

Produced by the Federal Environment Agency’s Indoor Air

Hygiene Commission

Members:

PD Dr. Wolfgang Bischof,UniversityClinicofJena,DepartmentofIndoorClimatology

Dr. Rolf Buschmann,NorthRhine-WestphaliaConsumerCentre,Düsseldorf

Dr.Thomas Gabrio,StuttgartDistrictCommissioner’sOffice,Baden-WürttembergHealthAgency(Landesgesundheitsamt)

PD Dr. Steffen Engelhart,InstituteforHygieneandPublicHealth,Bonn

Dr. Birger Heinzow,Schleswig-HolsteinSocialServicesAgency(LandesamtfürsozialeDienste),Kiel

Prof. Dr. Olf Herbarth,FacultyofMedicine,UniversityofLeipzigandHelmholtzCentreforEnvironmentalResearch(UFZ),Leipzig

Prof. Dr. Caroline Herr,BavarianHealthandFoodSafetyAuthority,Oberschleißheim

Dr. Hermann Kruse,UniversityHospitalSchleswig-Holstein,InstituteofExperimentalToxicology,Kiel

PD Dr. Susanne Lau,BerlinFreeUniversity,DepartmentofPaediatricPneumol-ogyandImmunology

Dr. Wolfgang Lorenz,InstituteforIndoorEnvironmentDiagnostics,ToxicologyandBuildingPhysics,Düsseldorf

Dr. Inge Mangelsdorf,FraunhoferInstituteforToxicologyandExperimentalMedicine,Hanover

Prof. Dr. Volker Mersch-Sundermann,InstituteofEnvironmentalMedicineandHospitalEpidemiology,Freiburg

Dipl.-Chem. Wolfgang Misch,GermanInstituteforConstructionEngineering(DIBT),Berlin

Prof. Dr. Henning Rüden,HELIOSHospitalGroup,Berlin


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Dr. Helmut Sagunski,HamburgDepartmentofHealthandSocialServices(BehördefürSozialesundGesundheitderFreienHansestadtHamburg)

Prof. Dr. Tunga Salthammer,FraunhoferInstituteforWoodResearch,Wilhelm-Klauditz-Institut(WKI),Braunschweig

Prof. Dr. Klaus Sedlbauer,FraunhoferInstituteofBuildingPhysics,Valley

The following also contributed their expertise:

Dipl.-Ing. (FH) Torsten Fenske,FederalMinistryofTransport,BuildingandUrbanDevelopment,Berlin

Dr. Andreas Gies,FederalEnvironmentAgency,Berlin

Dipl.-Ing. Friedrich Hamp,IntegriertesPlanen-Architekten-Ingenieure,Munich

Dr. Wolfgang Heger,FederalEnvironmentAgency,Berlin

Dipl.-Ing. Hans-Dieter Hegner, FederalMinistryofTransport,BuildingandUrbanDevelopment,Berlin

Jens Küllmer,FederalMinistryfortheEnvironment,NatureConservationandNuclearSafety,Bonn

Dr. Heinz-Jörn Moriske,FederalEnvironmentAgency,Berlin

Dr. Friederike Neisel,FederalInstituteforRiskAssessment,Berlin

Dr. Wolfgang Plehn,FederalEnvironmentAgency,Berlin

Dr. Regine Szewzyk,FederalEnvironmentAgency,Berlin

Dr Birgit Wolz,FederalMinistryfortheEnvironment,NatureConservationandNuclearSafety,Bonn


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Contents

General

I Introduction, objectives................................................................................................ 7

. I-1.The.issue............................................................................................................... 7

. I-2.Purpose.and.target.groups............................................................................... 8

. I-3.Structure.of.the.guidelines............................................................................... 9

. I-4.Current.situation.in.German.schools............................................................ 10

. I-5.Parameters......................................................................................................... 12

II Terms and regulations ................................................................................................ 13

III Further reading........................................................................................................... 14

Part A Hygiene requirements in the practical running of schools

. A-1.General.hygiene.requirements..................................................................... 17

. A-2.Cleaning.procedures...................................................................................... 19

. A-3.Ventilation.requirements............................................................................... 24

. A-4.Requirements.for.and.cleaning.of.school.swimming.pools..................... 26

. A-5.Minor.building.works.and.renovations....................................................... 28

. A-6.Workshops,.laboratories.and.home.economics.practical.areas.............. 32

. A-7.Copiers,.printers.and.PCs............................................................................... 34

Part B Indoor air pollutants in schools

. B-1.Inorganic.gases................................................................................................ 35

. B-2.Volatile.organic.compounds.(VOCs)............................................................. 39

. B-3.Formaldehyde.................................................................................................. 52

. B-4.Semi-volatile.organic.compounds.(SVOCs).................................................. 54

. B-5.Dust.................................................................................................................... 60

. B-6.Fibre.dust.......................................................................................................... 63

. B-7.Biological.substances...................................................................................... 68

. B-8.Radiation.(Radon)............................................................................................ 72


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Part C Structural and indoor climate requirements

. C-1.Structural.requirements,.fixtures.and.fittings.for.indoor.areas............... 75

. C-1.1.Building.shell................................................................................................ 76

. C-1.2.Extensions.and.conversions........................................................................ 79

. C-1.3.Fixtures.and.fittings.for.indoor.areas........................................................ 84

. C-2.Building.climate.............................................................................................. 86

. C-2.1.General.physiological.requirements......................................................... 86

. C-2.2.Technical.requirements............................................................................... 88

. C-2.3.Ventilation.technology................................................................................ 92

. C-2.4.Acoustic.requirements................................................................................. 93

Part D Procedures in problem cases

. D-1.Basic.procedures.............................................................................................. 99

. D-2.Case.studies.................................................................................................... 102

. D-2.1.Mineral.fibres.from.suspended.ceiling.construction........................... 102

. D-2.2.Chloronaphthalene.in.prefabricated.school.buildings........................ 103

. D-2.3.Odour.pollution.in.classrooms.after.the.long.holidays....................... 104

.D-2.4.Persistent.indoor.air.pollution.resulting.from.the.use.of...solvent-based.cleaning.product.on.woodblock.floors......................... 106

. D-2.5.Indoor.air.pollution.from.dibasic.dimethyl.esters.(DBE)..................... 107

. D-2.6.Health.problems.in.the.new.wing.of.a.primary.school...................... 109

Part E Remediation guidelines and procedures

. E-1.Asbestos............................................................................................................111

. E-2.Polychlorinated.biphenyls............................................................................ 112

. E-3.Pentachlorophenol........................................................................................ 113

. E-4.Polycyclic.aromatic.hydrocarbons................................................................114

Appendices

Appendix 1: (Specimen) hygiene plan for schools...................................................................117

Appendix 2: Index............................................................................................................... 129


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GENERAL

I Introduction, objectives

I-1 The issue

Airpollutantsinsideschoolspresentahygieneproblem.Theindoorpol-lutionobservedinsideschoolbuildingscanbetracedbacktoavarietyofcauses,suchaspoorconstruction,failingsinventilationengineering,incorrectventilationroutines,andtheuseofparticularbuildingmaterials,fittingsorcleaningproductswhichreleasechemicalsintotheair.Microbialproblems(mouldgrowth)alsoplayasignificantpartinschoolbuildings.

Inrecentyearstherehasbeenmuchdiscussionabouthealthyandhygi-enicallyacceptableindoorairqualityinschools.Someschoolshavebeenextensivelyrenovatedinthelastfewyearsbecauseofsuspectedasbestos,PCBsandotherindoorpollutants.Neverthelesstherearestillverymanyschoolswhosebuildingsareindireneedofmodernisationonaccountofinadequatebuildingmaintenanceworkandlackoffinanceatthelocalauthority.TheintroductionoftheBuildingEnergyConservationOrdinance[Energieeinsparverordnung,EnEV]in2002(amendedin2007)placesnewdemandsonallthoseinvolvedinthemodernisationofschoolbuildings.Theoutershellandthewindowsareintentionallymadeairtightinordertomeetenergyconservationregulations.Thedisadvantagecanbeanincreaseinchemicalandbiologicalsubstancesintheairinsideifthereisinadequateventilation.Therefore,ifschoolbuildingsrequireupgradingforenergyefficiencyorotherreasons,specificregulationsmustbeobservedsothatin-doorairhygieneproblemsdonotariselater.Theseguidelinessetoutwhatshouldbetakenintoaccountfromahygieneperspectiveandshouldhelptoidentifysolutions.

Inthe2000“GuidelinesforIndoorAirHygieneinSchoolBuildings”theFederalEnvironmentAgencydrewattentiontohygieneproblemsandcleaninginschools.Newchallengessuchastheproblemsofsuspendedpar-ticulatematterandcarbondioxideandtheneedtoupgradebuildingstomeetenergyefficiencystandardshavehowevermadeupdatingnecessary.

Newchemicalsubstancestobefoundintheairinsideschoolbuildingsandtheirsignificanceforhygienearedealtwithintheguidelines,asistheproblemofsuspendedparticulatematterinschools,theemissionofultra-fineparticlesfromprinters,andtheissueofmouldgrowth.Onechapterisdevotedentirelytotheimportantsubjectofventilation.Here–inschoolsaselsewhere–aparadigmshiftmaypossiblyoccur,sinceinsomecases


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naturalventilationviawindowsisnolongeranadequatelypracticalandlastingwayofachievingacceptableindoorairquality.Thisisespeciallythecasewiththeconcentrationofcarbondioxide,whichwasrecognisedbyPettenkofermorethan150yearsagoastheindicatorof“bad”airintheindoorenvironment.Todaycarbondioxideisonceagainameasureofthequalityofindoorairinschoolbuildings.Howtotakeeffectiveremedialac-tionagainsttheCO

2probleminclassroomsissetoutintheGuidelines.

I-2 Purpose and target groups

The“new”Guidelinesareintendedasaresponsetocurrentrequirementsinschoolpractice.Therecommendationsmadehereaimtohelptoavoidmistakes–fromanindoorairqualityperspective–inmodernisingschoolbuildings,andtoprovidehygiene-specificsupportintheplanningofnewschoolbuildings.

TheGuidelinesrelateprimarilytoclassroomsandassemblyroomsinschoolsandvocationalcollegesinwhichpupilsregularlyhavelessons.Theyshouldbeappliedbyanalogytoothertypesofschoolsandcarefacilitiessuchasdaynurseries.Manyrecommendationsarealsovalidforindoorspacesinpublicbuildingsotherthanschools.Otherstatutoryregulations(OrdinanceonHazardousSubstances[Gefahrstoffverordnung],etc.)whichapplytospecialisttechnicalareasofschoolbuildings(forexample,homeeconomicspracticalareas,workshops,laboratories)willnotbeaddressedfurtherintheseGuidelines.

TherecommendationsmadeintheGuidelinesalsoapplytotemporaryschoolbuildings(“demountables”).


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I-3 Structure of the Guidelines

The Guidelines are laid out as follows:

IntheGENERALSECTIONthetargetsoftheGuidelinesandthetargetgroupsareaddressed.ThecurrentindoorhygienesituationinGermanschoolsisdescribed,followedbytheparameterswithregardtope-ripheralissueswhichwillnotbedealtwithfurther.Varioustermsareexplainedandtherearesuggestionsforfurtherreadingonthesubjectofindoorairhygiene.

PART Adealswiththehygienerequirementsinthepracticalrunningofschools.Besidesgeneralrequirementsformaintenanceandoperationtheimportantissuesofcleaningandventilationareconsidered,aswellasminorbuildingworks.

PART Bprovidesanoverviewofimportantchemicalandbiologicalcontaminantsinschools.

PART Clooksatbuildingandairconditioningrequirements.Theimportantissueofacousticrequirementsisalsoaddressed.

PART Dshowshowtodealpracticallywithproblemcasesandlistscasestudieswith“typical”procedures.

PART Eprovidesabriefoverviewofexistingrenovationguidelines

TheAPPENDIXcontainsaspecimenhygieneplanforschoolsandanindex.

TheGuidelinesareintendedontheonehandforteachers,pupilsandparentsasthosedirectlyorindirectlyaffected,andfortheschoolgovernorsandthosepeo-pleateducationauthorities,planningdepartments,departmentsofhealthandtheenvironmentwithresponsibilityforschoolsontheotherhand.InadditiontheGuidelinesprovideinformationforallprofessionalgroupsinvolvedinplan-ning,building,renovatingormodernisingschoolbuildings.

Who are the Guidelines aimed at?


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I-4 Current situation in German schools

TheconditionofschoolsinGermanyisoftenunsatisfactoryintermsofthefabricofthebuildings.Olderbuildingsexhibitproblemssuchasill-fittingwindows,leakinessandsignsofwearandtearonbrickworkandroofs,aswellasdampdamageasaresultofplumbingleaks.Thenumberofnewbuildingserectedafter1990iscomparativelysmall.

Todaytherearearound34,000mainstreamschoolsandabout10,000voca-tionalcollegesinGermany.

Amongthemain(air)contaminantsinschoolsare:

Increasedcarbondioxideresultingfrominadequateventilationandairtightwindows.

Excessivedampinthestructureofthebuildingorintheindoorair,resultinginmicrobialgrowth.

Emissionsfrombuildingmaterials,fixturesandfittings.

Diverseodoursinthecaseofinadequateventilation.

Emissionsfromcleaningmaterials.

Possiblereleaseofdustandfumesintechnologyandsciencelessons.

Particulatematterarisingfromdischargesfromoutdoorandindoorsources.

Amongtheproblemsmentionedbypupils,parentsandteachers inrelationtobeinginschoolaregeneraldisorderssuchasheadaches,fatigueandpoorcon-centration.Furthermore,symptomssuchas irritationsof theupperrespiratorytractsandeyes,sinusinfectionsandtheoccurrenceofallergicsymptomscanalsobetracedbacktotimespentinschools.

What sort of health problems are reported after spending time in schools?


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Manyschoolbuildingsareclearlyinneedofrenovationonaccountoftheirgreatageandmanyyearsofintensiveuse.Inrecentyearsthefireandhealthandsafetyregulationshavealsobecomeevermorestringent.TheBuildingEnergyConservationOrdinancedemands,amongstotherthings,thatinnew-buildsandcomprehensiverenovationsofexistingbuildingstheoutershellismadeairtighttominimisetheuseofprimaryenergy.Thedis-advantagewhenthereisinadequateventilationcanbeapossibleaccumu-lationofthechemicalandbiologicalsubstancesreleasedindoors.

Unfortunately,manylocalauthoritieslackthemoneyforcomprehensiveandspecialistrenovations.Theconsequenceisdamppenetrationthroughgapsinwalls,roofsandpipework.Ill-fittingwindowsareactuallyarealadvantagefromahygieneperspective,astheyhelptoallowaminimumofaircirculationinclassroomsevenifthewindowsanddoorsareclosed.However,ill-fittingwindowsleadtoenergylossandmayexposepupilsandteacherstodraughtsduringlessons.

Theremediationnecessary,i.e.theextentoftherepairs,modernisationandrenovationofschoolbuildings,dependsontheactualconditionofthebuildingineachcase–oldandnewbuildingsareequallyaffected.Becauseofthedemandsontheuseofschoolbuildings,particularlytheclassrooms,regularmaintenanceandrepairsareextremelyimportantinordertoavoidstructurallyrelatedhygieneproblemslater.

Ifextensiverenovationworkisduetotakeplace,acomprehensiveair-con-ditioningschemeshouldbeincludedintherenovationplans,inordertoimprovetheventilationsituationduringlateruse.Thiscaninvolveair-con-ditioningsolutions,butcouldalsobeadesignforanimprovedventilationregime.Sensor-operatedsolutions(openingthewindowswhenthereistoomuchcarbondioxideintheair)areequallypossible.

Noisecontrolcanbeanotherprobleminschoolbuildings.Manyclassroomssufferfromundesirablereverberation.Therecanthenbesubstantialinter-ferencetocommunicationandauralcomprehensionbetweenteachersandpupils.

Justasimportantasgoodacousticsisadequateandevenlighting.Windowsofadequatesizeareinanycasecompulsory.However,ifthesefaceexclu-sivelywestandeast,itcancauseexcessiveheattobuildupintheroomsinsummer.South-facingwindowsaregenerallylessofaprobleminthisre-spect,contrarytolong-standingopinion,becausethesunisrelativelyhighintheskyatmidday,makingiteasiertoemployshadingatthewindows.


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Theneedtotakeprecautionsagainstoverheatingofroomsinsummerwillincreaseinthecourseoffutureclimatechanges.

I-5 Parameters

Oneindoorhygieneproblemofthelastdecadehasrecentlybeencon-signedtothepast–tobaccosmoke.OwingtothelawsprotectingagainstthedangersofpassivesmokingwhichhavenowcomeintoforceinalmostallGermanLänder,ageneralbanonsmokinginschoolsandschoolplay-groundsappliesthroughoutGermany.Smokingroomsarenotpermittedinschools.

Under Länder building regulations, it is strictly prohibited to use windowlessroomsforlongperiodsofoccupation,andthereforealsoasclassroomsinschools.

Is it permitted to use windowless rooms as classrooms?

Tobacco smoke: thenegativehealtheffectsof tobacco smokearewell enoughknown. There is an absolute ban on smoking in school buildings and on thewholeschoolpremises.

What is not covered in these guidelines?


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II Terms and regulations

AccordingtoarecentstudyaspartoftheFederalEnvironmentAgency’s2007NationalHealthSurveyofChildrenandAdolescents,childrenagedbetween3and14spend90%ofthedayindoorsinwinter.Eveninsummeradolescentsspendpartofthedayinenclosedspaces.Theindoorenviron-mentincludesthehome,school,nurseryschools,theatres,cinemas,librar-ies,sportshalls,departmentstores,discothequesandtransport.Thus,fromahygieneperspective,thestudyandreductionofindooraircontaminantsisofcentralimportanceforhealthandwell-being.

Anadhocworkinggroup,madeupofmembersoftheFederalEnviron-mentAgency’sIndoorAirHygieneCommission(IRK)andtheWorkingGroupoftheSupremeHealthAuthoritiesoftheFederalStates(AOLG),aredevisingguidelineindoorairvaluesforsinglesubstancesbasedonaproceduralmodelpublishedin1996(cf.SectionB-2).Accordingtothis,twoguidelinevaluesaregenerallyestablishedforindooraircontaminants.ValueII(RWII)isderivedonahygiene/toxicologybasis,takingintoac-countbothpopulationgroupswithsensitivereactionsandchildren,andrepresentstheconcentrationofasubstancewhich,ifreachedorexceeded,requiresimmediateaction,sincethisconcentrationislikelytoendangerhealth,especiallyinpeoplewithsensitivities,iftheyspendalongtimeintherooms.Theneedforactionshouldbeunderstoodastheneedforimmediateinspection,e.g.withaviewtodecidingonremedialmeasurestoreduceexposure.ValueI(RWI)iscalculatedfromRWII,takingintoaccountaconventionallyestablishedsafetyfactor(generallyof10),andcanserveasthetargetremediationvalue.IfavalueisbelowRWIwhenasinglesubstanceisexamined,accordingtocurrentknowledgenodamagetohealthistobeexpected,eveninthecaseoflifelongexposuretothesub-stanceconcerned.ForprecautionaryreasonsactionalsoneedstobetakenintheregionbetweenRWIandRWII,forinstance,toincreaseventilation.

Ingeneral,pollutionintheairinaclassroomshouldbetreatedandassessedinthesamewayaspollutioninthehome.Healthandsafetyatworkregulations,whichapplytoindividualareasoftheschool(workshops,etc.),donotprecludethis.Airpollutionlimitvaluesapplicabletoworkplacescontaminatedbyindus-trialproductionprocessescannotbeappliedtotheinsideofschools.


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Anoverviewoftheindoorairguidelinevaluesderivedonthebasisofthismodel,whichalsoappliestoindoorareasinschools,canbefoundonlineatthefollowinglink:http://www.umweltbundesamt.de/gesundheit/innenraumhygiene/richtwerte-irluft.htm.

III Further reading

The following collection includes a range of literature intended to provide the reader with further information on indoor air hygiene.

AmtderNiederösterreichischenLandesregierung,AbteilungUmwelthygiene:LeitfadenfürdieInnenraumlufthygienebetreffendVorbeugung,Untersuchung,BewertungundSanierungvonSchim-melpilzbelastungeninWohngebäuden[LowerAustrianstategovern-ment,DepartmentofEnvironmentalHealth:Guidelinesforindoorairhygienewithregardtotheprevention,investigation,assessmentandremediationofmouldcontaminationinresidentialbuildings].St.Pölten2007.http://www.noe.gv.at/bilder/d25/Schimmelpilzleitfaden.pdf

BayerischesLandesamtfürGesundheitundLebensmittelsicherheit:LuftqualitätinöffentlichenInnenräumen–FrischeLuftanbayerischenSchulen[BavarianHealthandFoodSafetyAuthority:Airqualityinpublicindoorspaces–freshairinBavarianschools].http://www.lgl.bayern.de/gesundheit/umweltmedizin/projekt_luft.htm

BerufsgenossenschaftderBauwirtschaft(BGBAU):Gesundheitsgefähr-dungendurchbiologischeArbeitsstoffebeiderGebäudesanierung(BGI858).HandlungsanleitungzurGefährdungsbeurteilungnachBiostoffverordnung[Buildingtradeassociation(BGBAU):Healthhaz-ardsfrombiologicalmaterialsusedinbuildingrenovation(BGI858).InstructionsforriskassessmentinaccordancewiththeOrdinanceonBiologicalAgents].(2006)http://www.bgbau-medien.de/site/asp/dms.asp?url=/zh/bgi858/titel.htm

FreieundHansestadtHamburg:FrischerWindinSchulen.Informa-tionsbroschüre.Hamburg,BehördefürWissenschaftundGesundheit[FreeandHanseaticcityofHamburg:Abreathoffreshairinschools.Informationleaflet.HamburgMinistryofScienceandHealth].(2005)

InstitutfürangewandteHygiene:ÖsterreichischeSchulen–Hygiene-plan[InstituteofAppliedHygiene:Austrianschools–hygieneplan].Graz(2007)www.schule.at/gesundheit/hygieneplan2007.pdf


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LandesgesundheitsamtBaden-Württemberg:SchimmelpilzeinInnen-räumen–Nachweis,Bewertung,Qualitätsmanagement.LGA-Berichte,[Baden-WürttembergHealthAgency:Mouldinindoorenvironments–detection,evaluation,qualitymanagement.HealthAgencyreports]Stuttgart(2001)(revised2004)

LandesgesundheitsamtBaden-Württemberg:HandlungsempfehlungfürdieSanierungvonmitSchimmelpilzenbefallenenInnenräumen[Baden-WürttembergHealthAgency:Recommendedprocedurefortheremediationofindoorareasattackedbymould],2ndrevisededition,Stuttgart(2006)

LandesgesundheitsamtBaden-Württemberg:MusterhygieneplanfürSchulenundähnlicheGemeinschaftseinrichtungen[Baden-Württem-bergHealthAgency:Specimenhygieneplanforschoolsandsimilarcommunityinstitutions].LGA,Stuttgart(2005)

NiedersächsischesLandesgesundheitsamt(NLGA):LüftungsempfehlungfürArbeitsräume(Büro-undUnterrichtsräume)[GovernmentalInsti-tuteofPublicHealthofLowerSaxony:Recommendedventilationforindoorworkplaces(officesandclassrooms)].NLGA,Hanover(2004)

NiedersächsischesLandesgesundheitsamt(NLGA):„AufatmeninSchulen“–LuftqualitätundRaumklimainUnterrichtsräumen[Govern-mentalInstituteofPublicHealthofLowerSaxony:„Breathedeeplyinschools”–airqualityandindoorclimateinclassrooms].NLGA,Han-over(2005)

NiedersächsischesLandesgesundheitsamt(NLGA):Rahmenhygienep-lanfürSchulen(Entwurf)[GovernmentalInstituteofPublicHealthofLowerSaxony:Frameworkhygieneplanforschools(draft)],Hanover(2007)

Rahmen-HygieneplanfürSchulenundsonstigeAusbildungseinrichtun-gengemäß§36Infektionsschutzgesetz.Länder-ArbeitskreiszurErstel-lungvonHygieneplänennach§36IfSchG[FrameworkhygieneplanforschoolsandothereducationalestablishmentsinaccordancewithArticle36ProtectionagainstInfectionsAct.Federalstates’workinggroupforthecreationofhygieneplansinaccordancewithArticle36ProtectionagainstInfectionsAct],Potsdam(2003)

Umweltbundesamt:LeitfadenzurVorbeugung,Untersuchung,Bew-ertungundSanierungbeiSchimmelpilzwachstuminInnenräumen(Schimmelpilz-Leitfaden)[FederalEnvironmentAgency:Guidelinesontheprevention,investigation,assessmentandremediationofmouldgrowthinindoorareas],Berlin/Dessau2002


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Umweltbundesamt:LeitfadenzurUrsachensucheundSanierungbeiSchimmelpilzwachstuminInnenräumen(Schimmelpilz-Sani-erungsleitfaden)[FederalEnvironmentAgency:Guidelinesoniden-tifyingthecauseandontreatingmouldgrowthinindoorspaces].Berlin/Dessau2005

Umweltbundesamt:Bauprodukte:SchadstoffeundGerüchebestimmenundvermeiden[FederalEnvironmentAgency:Buildingmaterials:Iden-tifyingandavoidinghazardoussubstancesandodours].Dessau2006

UnfallkassedesLandesNordrhein-Westfalen(2008):UmsetzungderGe-fahrstoffverordnunganSchulenTeil1und2[NorthRhine-WestphalianAccidentInsurance(2008):ImplementationoftheHazardousSub-stancesOrdinanceinschoolsparts1and2]:availableat<http://www.unfallkasse-nrw.de/index.php?id=4&no_cache=1>linktodownloadthedocu-ments“PräventioninNRW3und4-UmsetzungderGefahrstoffverord-nunganSchulenTeil1und2”[PreventioninNorthRhine-Westphalia3and4-ImplementationoftheHazardousSubstancesOrdinanceinschoolsparts1and2]

UnitedKingdom:DepartmentforCommunitiesandLocalGovernment:TheBuildingRegulationDocuments.BuildingBulletin101,VentilationofSchoolBuildings.London(2006)


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PART A: Hygiene requirements in the practical running of schools

A-1 Generalhygienerequirements

Theseguidelinesrelatetoairhygienequestionsinschoolbuildings.How-ever,inthepracticalrunningofschoolsthereareoftenaspectsoverandaboveairhygienetoconsider.

Justasinotherbuildings,specificfundamentalhygienerequirements,orrathergeneralhygienerequirements,mustbemetinschools,inorderforittobepossibletospendtimeinthebuildingwithoutexperiencinghealth-relatedproblems.

Includedinthegeneralhygienerequirements(someofthepointslistedcanonlybeimplementedwhenplanningnew-builds)are:

Theschoolsiteshouldbelocatedfavourablywithrespecttoairbornepollut-antsinthesurroundingair,i.e.thereshouldbeaslittlepollutionbyhazard-oussubstancesaspossibleinthevicinity.Thereshouldbelowtrafficandindustrialnoiselevelsandasaferoutetoschoolforpupils.Converselythenoiseemissionsfromtheschoolitselfshouldasfaraspossiblenotcreateanysignificantnuisancetotheneighbourhood.

Theclassroomsshouldbeofsufficientsizeandbearrangedpracticallyinrelationtothewaythesunmovesround.Wheretheproportionofglassinthefaçadeexceeds50%,asisusualinschoolconstruction,allfaçades,withtheexceptionofwindowsfacingduenorth,requireshading.Thismusthavevariablecontrols.

Adequatelightfromdaylightand–tosupplementit–fromartificiallightingshouldbeprovidedatalltimesofdayandthroughouttheyear.Consequentlythedepthoftheroomshouldnotexceedtwotothreetimesitsheight.Thelightreflectanceofthecomponentsurfacesshouldbeashighaspossible(canbeachievedbymeansonlightcoloursonwallsandceilings).

Effectivestructuralnoiseinsulationshouldpreventnoisetransfertoneigh-bouringrooms,corridors,etc.Theclassroomsshouldhavelowreverbera-tiontimesforbetterspeechintelligibility(DIN[GermanInstituteforStand-ardisation]180412004/2005;Acousticalqualityinsmallandmedium-sizedrooms).


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Windowsorotherventilationoptionsshouldpermit,throughnaturalventi-lation,thereductionoftheconcentrationofairpollutantsbeingproducedintheroom.Allwindowsshouldbeeasytoopen.

Inareasinwhichworkingwithhazardoussubstancesisarequirement,suchasinlaboratories,mechanicalventilationisabsolutelyessential.Inthecaseofextremelypollutedoutsideairconditionstheinstallationofair-con-ditioningsystemsshouldbeconsidered.

Allareasoftheschoolbuildingshouldbeequippedwithadequateheating,wherebytheradiatorsshouldbeofadequatedimensions,ifpossibleshouldberunatlowtemperatures,andshouldbeeasytoclean.

Thefurnishingsandequipmentintheroomsshouldbeasfreeaspossibleofemissionshazardoustohealth.Whenpurchasingnewfurnitureattentionshouldbepaidtoenvironmentalqualitylabels(cf.SectionA-5).

Propercloakroomsshouldbeavailableinsufficientnumberssothatwetclothingcandryandair.Forfiresafetyreasonslockersandcoatpegsareoftennotlocatedincorridorsnowadays,butintheclassrooms.Thismakesadequateventilationanddehumidificationintheseareasallthemoreim-portant.

Asufficientnumberoftoiletsequippedwithwashbasinsshouldbeavailableforpupilsandteachers.Thefacilitiesmustbecleanedandservicedregularly.

Playgroundsandindoorrecreationroomsofsufficientsizeshouldbeavail-ableforuseatbreaktimes.

Allareasofthebuildingshouldbeeasytoclean.

Regulations in individual Länder, in accordance with which windows havebeenstructurallyormanuallyalteredforsafetyreasonssothattheycannotbeopened–forexample,topreventsomeonefallingoutofthewindow–areunac-ceptableintheopinionoftheIndoorAirHygieneCommission.Accidentsmustbepreventedthroughothermeasures(includingallpupilsleavingtheclassroomduringbreaks,theclassroomsbeinglockedduringbreaks).


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A-2 Cleaning procedures

Cleaningproceduresmustbecarriedoutregularlyandproperlyinschoolsonaccountoftheintensiveuse,includingbyvulnerableusergroups.TheminimumrequirementsforcleaningschoolbuildingsandsportsfacilitiesbelongingtothemaresetoutinDIN77400“Cleaningservices–schoolbuildings–requirementsforcleaning”.Thisappliesregardlessofwhetherthecleaningisundertakenbytheschool’sownemployeesorbycleaningagencies.

IntheintroductiontotheaforementionedDINstandarditisnotedthatcleanlinessandhygieneareofparticularimportanceinschoolbuildingsandthattheenvironmentinwhichchildrenandyoungpeopleareedu-catedinfluencestheirhealthaswellastheirownperceptionofhygieneandtheirhabitsinthatrespect.Furthermore,itstatesthatparticularimpor-tancemustbeattachedtoschoolcleaningrequirements,regardlessoftheprevailingbudgetsituationwithinthelocalauthorities,andtothecleaningintervalsresultingfromit.

AccordingtoDIN77400oneofthegeneralrequirementsforhygieniccleaningofschoolbuildingsisthatthedustconcentrationiskeptwithinacceptablelimitsthroughsuitablecleaningmethods(e.g.washing).Whenselectingthecleaningmethodsandsystemsthelatesttechnologyshouldbeused,takingintoaccountenvironmentalconsiderations.

Whenestablishingcleaningintervalsinindividualschoolbuildingslocalconditionsmustbegivenparticularconsideration.Factorstobearinmindincludelocation,use(andalsoextracurricularuse),schoollayout,frequencyofuse,buildingfabric,natureoftheexternalgrounds(withunsurfacedar-easconsiderablymoredirtcanbeexpectedtobebroughtin)andseasonalinfluences.

Besides hygienically impeccable structural conditions, good accessibility to allroomsandareas,especiallywithregardtomakingcleaningeasy,theprovisionoflow-emissionequipment,andregularheatingandventilationarethebestprereq-uisitesforahygienicallysafesituationinschools.

What general hygiene considerations should be taken into account in the practical running of a school?


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ThecleaningintervalssetoutinDIN77400areminimum cleaning frequencies.InDIN77400itisemphasisedthat,dependingonlocalconditionsandthefactorsmentionedabove,morefrequentcleaningthanspecifiedinDIN77400maybenecessary.

Thefollowingcleaningproceduresarebasedontheseminimum cleaning frequenciesandshouldthereforenotbeappliedprescriptivelytoalllocalsituationsandseasonalconditionsequally.

Corridorsandstairwellstogetherwithclassroomsandteachingareasarethemostfrequentlyusedspacesinaschool.Theseareasbecomedirtyquickly.Theentrancearea,thetrafficareasofthegroundfloorandthestairstothefirstfloorshouldbecleaneddaily,evenseveraltimesdailyifnecessaryinwinter,whenmoremudisbroughtinfromoutside.Theothercorridorsandstaircasesshouldbecleanedatleasteveryotherdayinsummer,andmoreofteninwinterifnecessary.

Fromahygieneviewpointwashing,havingfirstremovedloose,coarsedirt,offersthebestoptionforeliminatingthevariouscontaminantsbroughtin-side.Dependingonthenatureandcompositionofthefloorstobecleaneditmaybesufficienttoaddeithersurfactantstothewashingwater,orelsespecialistcleaners(forflexiblefloor-covering)mustbeused.Morepreciseinstructionsinthisregardshouldbestipulatedineachindividualcaseafterconsultationwiththecleaningcontractorsorthefloormanufacturer.

Onlyinexceptionalcaseswillitbenecessarytocarryoutdisinfectantclean-ingorsurfacedisinfectionoffloorsincorridorsandstairwells.Forexample,thismaybethecaseifthereareincreasedoccurrencesofnotifiableinfec-tiousillnessesintheschool,whentherelevanthealthagencywillarrangeforappropriatemeasurestobetaken.Thisespeciallyincludesdisinfectinghandrails.Incasesofcontaminationwithblood,faecesandvomitdisinfect-ingcanalsobenecessary;however,thisshouldonlybecarriedoutbydes-ignatedstaffandunderstrictobservanceoftheschool’sexistinghygiene,ventilationandcleaningplan(seeAppendix1).

Inordertofacilitateregularwetcleaning(washing)ofcorridorsandstair-wellsinschoolsitisnecessaryfortheseareastobefittedwithsuitablefloor-ing.

Carpetsandcarpetingshouldthereforenotbeusedintheseareas(seepara-graphonCarpeting).

Classroomsandteachingareasshouldbecleanedregularly.Studieshaveshownthatperfectlyhygienicconditionscanbeachievedinclassroomsbywashingthefloorproperlyandwipingtabletopswithadampclotheveryotherday,ifexternalconditions(stateofthebuilding,localcircumstances)


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aregood.Especiallyinthewintermonthsandwithunsurfacedoutsideareas,andifthereisadditionaluse(e.g.after-schoolclubs)cleaningshouldbecarriedoutdaily.

Carpeting,whichislaidinsomeschoolsforreasonsofnoisecontrol,shouldalsobeproperlyvacuumedatleasteveryotherday,ifpossiblewithavac-uumcleanerfittedwithaHEPAfilterorwithacentralvacuumcleaningsystem(VDI[guidelinesfromtheGermanAssociationofEngineers]4709).Themanufacturer’sinstructionsshouldalsobeobserved.Inthiscase,too,morefrequentcleaningshouldbeassumedifincreaseddirtisbroughtinorthereisadditionaluse.Carpetinginclassroomsandteachingareascanposeahygieneproblem,asitismoredifficulttocleanthanhard,washablefloors.Forthisreasonlayingcarpetinginnewschoolbuildingsisnotrec-ommended.Ifcarpetshavetoberenewed,e.g.becauseofwearandtear,theyshouldifpossiblebereplacedwithhard,washableflooring.

“Cosy corners”presentaparticularhygieneprobleminschools.Theissuehereisoftensecond-hand,sometimesthreadbareupholsteredfurniture,whichisoftenpiledupwithcuddlytoyanimals,toys,cushionsandblan-kets.Iftheschoolacceptsthese“cosycorners”,whichhavefrequentlybeensetupwiththesupportoftheparents,theymustdefinitelybeincludedinthecleaningplanandcleanedthoroughlyaswellonaregularbasis,e.g.byvacuumingthematleastonceaweek.Itemskeptinthesecornersmustalsobesubjecttothecleaningprocedures.

Linoleumhasenvironmentaladvantagesowingtoitsnaturalconstituents–linseedoil,woodflour,limestoneandjute–andisoftenusedinpublicbuildings,althoughitrequiresregularspecialcarebecauseofitscomposi-tion.Whencleaningandcaringforlinoleumthereisadistinctionbetweencleaningafterinstallation,orinitialcleaning,maintenancecleaningbywashing,wipingwithadampmoporusingafloorcleaneranddeepclean-ingfollowedbyreplenishingtheprotectivefinish.Whenselectingcleaningandmaintenanceproductsforlinoleumabsolutecaremustbetakento

Areductioninpollutioninclassroomscannotbeguaranteedthroughcleaningalone.Cleaningisimportant,butthereductionofexistingsourcesofemissionsandregularventilationareequallyimportant.Throughventilationthecarbondi-oxideconcentrations(aclassicindicatorofinadequatefreshairsupply),increasedhumidityintheindoorairandpollutionbyhazardouschemicalsandparticulatematterarereduced.

Can cleaning alone improve the air quality in classrooms?


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useonlythosewithapHvaluebelowpH9,asproductsthataretooaggres-sivelyalkalineattackthenaturalmaterialsinlinoleumandcandestroythesurface.Forthisreasonsoftsoapmaynotbeusedeither.Itisrecommendedthatthecleaningstaffshouldbeobligedtoabidebythemanufacturers’relevantcareinstructions.

Sanitary areasandwashroomsincludingchanging roomsinschoolbuildingsareofparticularimportanceintermsofhygiene.Herethoroughcleaningmustbeundertakenatleastonceadayandfloorsscrubbedregularly(toremovesurfaceandground-indirt,havingfirstremovedcoarsegrit).Tiledwallsandfloorsareidealforthis.Surfacedisinfectantscanbeappropriateifnotifiableinfectiousdiseasesoccur.Inthiscasethehealthagencywillorganisesuitablemeasures.Cleaningproceduresinvolvingdisinfectantsarenotnecessaryinsanitaryareastopreventinfection,butcanbeappropriateintheeventofcontaminationofsurfacesbyfaeces,vomit,etc.

Staffrooms,school offices,administrative areas,offices and meetings roomsshouldbecleanedtwiceaweek,whilesiderooms(forlessonpreparation,teachingmaterials,etc.)shouldbecleanedatleastonceaweekandstoreroomsatleastonceamonth.

Gyms(usedonlybytheschool)andareaswithsimilarfunctions)mustbeproperlycleanedonadailybasis.Herethetypeofcleaningdependsonthefloorconstructionandthenatureofthefloorsurface.Withadditionalusebysportsclubsintheeveningandatweekendssuitablyexpandedcleaningprogrammesarenecessary.

Wheretherearekitchens and food distribution points,theprovisionsofRegula-tion(EC)No.852/2004onfoodhygieneshouldbeobserved.Thisappliesalsotoschoolmealskitchensandbythesametokenalsotohome economics kitchens.Inadditiontherelevanthygieneregulationsshouldalsobecom-pliedwithindining rooms.Thefloors,sinksandfittings,walltilesandstorageunits,tabletopsandkitchenappliances(cookers,etc.)andwashbasinsmustbecleanedoneachdayused(removingsurfaceandground-indirt,havingfirstremovedlargerdebris).

Asmoreandmoreschoolsgoovertoall-dayschooling,theyshouldensurethatasufficientnumberofwashbasinsisavailableintheschool.

Overandabovethemaintenancecleaning,deepcleaning,specialcleaningandcleaningofglassaswellascareprogrammesshouldbecarriedouttoensureadequatehygienestandardsandminimisedeterioration.Afterdeepcleaningadditionalprotectivecaremeasuresmayberequired,dependingonthetype,compositionandconditionofthesurfaces.Inparticular,pro-tectivefilmsonflooringmustbekeptingoodconditionthroughregular


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careprocedures.Athoroughcleaningandcareprogrammeinaccordancewiththecareinstructionsshouldbecarriedoutinallareasoftheschoolatleastonceayear.Thisinvolvesnotonlycleaningthefloors,butalsothefurnitureandotheritemsofequipment.

Forboththeroutinecleaningandthethoroughcleaningandcareonlycleaningproductswhichposenorisktohealthshouldbeused.Ifseveraldifferentcleaningproductsareused,acheckshouldbemadetoensurethattheproductsdonotneutraliseeachother’seffectandthatnosubstancesharmfultohealthareproducedbymixingthemtogether.Therecommen-dationsforuseshouldbefollowed.Safetyinstructionsandrisksposedbytheproductcanbeobtainedfromthesafetydatasheets.

Somesurfacedisinfectantscontainaldehyde(inrecentyearsaldehydessuchasglyoxalorglutardialdehydehavebeenusedincreasingly),quaternaryammoniumcompounds(QUATS),biguanideandamines.Somedisinfect-ants,ifusedincorrectly(toohighadoseoftheactivesubstancesinthesolu-tionemployed,inadequateorincorrectventilationmeasuresduringuse),canleadtoresiduesoftheiractiveagentsevaporatingintotheairbuildingoccupantsbreathe,resultinginharmtohumanhealth.

Forsanitaryareasapropercleanonceadayisessential;ifnecessarytheyshouldbecleanedmorefrequently.

Theentranceareauptothefirstfloorshouldbecleaneddaily,whiletheothercorridorsandstaircasesshouldbecleanedat leasteveryotherday.Classroomsandtabletopsshouldbecleanedthoroughlyatleasteveryotherday.Sportshallsandsimilarareasrequiredailycleaning.

Inotherareasoftheschoolcleaningprogrammesshouldbecarriedoutasneeded.

Theuseofaddeddisinfectantsisonlynecessaryinspecialcases(diseasesnotifi-ableundertheGermanProtectionagainstInfectionsAct[Infektionsschutzgesetz]orinthecaseofcontaminationwithblood,faecesorvomit).Disinfectantclean-ingshouldnotbeundertakeninanyareaoftheschoolwithoutspecificcause,i.e.justtopreventinfectionsingeneral.

Sanitaryareasandwashroomsshouldbefittedoutsothatsufficientnumbersofwashbasinsareavailable.Soapdispensersandpapertowelsystemsshouldprefer-ablybeinstalledbythewashbasins.

Theproductionanduseofcleaningplansistoberecommended.Inrelationtotheseitisadvisabletosetoutthecleaning,ventilationandotherhygieneproce-durestobefollowedina„ComprehensiveHygienePlan”.

What must be cleaned in school buildings, and how often?


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A-3 Ventilation requirements

Themostimportantfunctionofventilationistorenewtheindoorairbyextractingimpuritiesintheformofgasanddustandthemetabolicprod-uctsfromhumans(odours,carbondioxide,watervapour)andtosupplyfreshairfromoutside.Inadditiontherearephysiologicalrequirements:achievingthemostcomfortablepossibleairtemperatureandhumidityintheroom,andachievingthermalbalance.

Untilnow,becauseoftheprevailingclimateinGermany,schoolbuildingshavegenerallybeendesignedandbuiltinsuchawaythatnaturalor“freshair”ventilationthroughwindowsshouldsuffice.However,inunfavour-ablelocations(e.g.considerablenoisepollutionfromthevicinityorhighairpollution)theinstallationofventilationsystemsmaybecomenecessary.Inadditionspecialextractionsystemsarerequiredforlaboratorieswhereexperimentsproducinghighlevelsofsmokearecarriedout.

Whenusingventilationviawindowsorairventsinexternalwallsitisim-portanttoreducetheimpactofpossiblehighnoiselevelsfromoutside(e.g.trafficnoise,aircraftnoise)onclassrooms.Theinstallationofhighlysound-absorbentventilatingwindowsorsound-insulatedventilationductscanbenecessaryinthiscase.

Topreventtheroomsfromoverheatingthroughsolarirradiance,windows,fixedglazingandskylightsshouldallnotbelargerthannecessaryforap-propriatedaylightingwithoutglare.Wheretheproportionofglassinthefaçadeexceeds50%,asisusualinschoolconstruction,allfaçades,withtheexceptionofthosefacingduenorth,requiresunshading.Fixedsunshadingdeviceshavethedisadvantageofreducingincomingdaylight.Southerlyas-pectsare,however,easiertofitwitheffectivesun-protectiondevices.Thesedevicesmustnotimpairthewindowventilationandshouldnotencouragetheinflowofwarmairrisinguptheoutsidewall.

Thecriterionfortherenewalofairinaroomistheair-changenumber.Thisisthequotientfromthevolumeofthesupplyofexchangedairintotheroomandthevolumeoftheroom.Itisdefinedasadimensionlesssizeperunittime(mostlyonehour).Anair-changenumberof1/h(“oneperhour”)meansthat(arithmetically)theentirevolumeofairinaroomiscompletelyreplacedinonehour.Adistinctionismadebetweennaturalairexchange,whichoccursasaresultofwindpressuredifferenceandthermallift,andmechanicalairexchangebymeansofventilationdevices.Withnaturalven-tilationthroughwide-openwindowstheair-changerateisaround10–20/h.


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Themorepollutedtheindoorairiswithcarbondioxide(CO2)andother

substances(cf.SectionsB-1toB-4),thegreaterbecomestheairexchangerequired.Withnormalclasssizesseveralchangesofairperhourarere-quiredfortheclassroom,inordertoextractenoughofthecarbondioxideproducedbythepupilsexhalingfromtheairintheroom.Thenecessaryairexchangeofaround25to30m3/hperpersoncannotbeachievedthroughnaturalventilationwithclosedwindows(knownaswindowgapventila-tion),butonlybyregularlyopeningthewindowswideforshortperiods(“intensiveventilation”foratleast5,preferablyupto10minutes).Evenmoreeffective(ifpossible)iscross-ventilationviawindowsoppositeeachother.Thereforetheroommustreallybeairedineverybreakbetweenlessonsand–withdoublelessonsorlargeclasses–duringlessonsaswell.(Ifthisisnecessary,thepupilsshouldleavetheroomsforsafetyreasonsdur-ingthistime.)Itisalsorecommendedthatintensiveventilationbecarriedoutbrieflyonceortwiceduringthelesson.

Basicallyusingthewindows.Todothisallwindowsinteachingareasshouldbeopenedwide(intensiveventilation,cross-ventilation)beforeschoolstartsandatleastduringeverybreak(specificallyincludingthefiveminutebreaks,whenthepupilsnormallystayintheroom!)forthewholedurationofthebreak.Ventila-tionbytiltingthewindowsislargelyineffective,ashardlyanyairisreplacedinthisway.

In the winter months heat inevitably escapes during ventilation. To minimiseenergy loss theradiatorvents shouldbeclosedduringventilation.Alternative-lyautomaticventswithwindowcontact switchescanbe installed.Thereserve capacityoftheheatgenerationshouldpermitswiftreheating.

The reservecapacityof theheating systemmustallow the rooms towarmupagainquicklyafterventilation–asotherwiseventilationwouldnotreallybecon-sideredacceptablebytheusersofrooms.

Ifmanualventilationwithwindowsisnotadequatetocreateormaintainhygieni-callyidealairqualityduringlessonsaswell,mechanicalventilationoptionscanbeinstalledtoensuresufficientairreplacementevenwiththewindowsclosed.Highlevelsofnoiseandotheremissionsoutsidecanalsomakemechanicalven-tilationsystemsnecessary.Ifsystemsofthissortareinstalled,regularservicingmustbeguaranteedonhygienegrounds.

How should the rooms be aired?


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A-4 Requirements for and cleaning of school swimming pools

Swimmingisextremelyvaluableinpromotinggoodhealth.Itisalsopar-ticularlyimportantinP.E.lessons.Someschoolshavetheirownswimmingpools.Swimmingishealthy,butcanalsocausehygieneproblems.Everyswimmerreleasesonaverage2.3to2.6billiongerms,possiblyincludingpathogenicmicro-organismssuchasstaphylococcus aureus,streptococcus pyogenes, salmonella spec.aswellaspathogenicviruses,intothewater.

Thereforeitisessentialtoensurethatnohealthrisksareposedbythewa-terinswimmingandbathingpools.TheProtectionagainstInfectionsAct(Article37)providesthelegalfoundationforthis:“Waterincommercially-runswimmingorbathingpools,publicbathsandothernotexclusivelypri-vatelyusedfacilitiesmustbesuchthatinusingitthereshouldbenoneedforconcernsoverharmtohumanhealth,especiallythroughpathogens”.

Inordereffectivelytopreventthetransferenceofpathogens,disinfectionofthewaterinthepoolisessential.Chlorinehasforalongtimeprovedvaluableasaneffectivedisinfectantonaccountofitsrapidandlong-lastingmicrobiocidalaction.Chlorinegasorhypochloritecompounds(DIN19643)areused.Insomepoolsbromineisalsoemployed,againbecauseofitsmicrobiocidaleffect.However,itismoredifficultforpooloperatorsandhealthagenciestomonitorthistypeofdisinfectionproperly,sincewiththeDPDmethodnormallyusedformonitoringitisimpossibletodistinguishbetweenfreeandboundbromine.ForthatreasonbromineisnotincludedasadisinfectantintheFederalEnvironmentAgency’srecommendation“Hygienerequirementsatpoolsandtheirsupervision”(Bundesgesundheits-bl-Gesundheitsforsch-Gesundheitsschutz9,2006).Itshouldbenotedwhenusingchlorineandbrominethatbothsubstancescauseirritation.Further-more,becauseofthereactionofchlorineorbrominewithwaterborneorganicsubstances,whicharemainlybroughtintothepoolwaterbyswim-mers(e.g.organiccompoundsfromurine,sweat,mucus,hair,flakesofskin,cosmetics),butwhicharealsotosomeextentalreadypresentinthewaterused(e.g.humicsubstances)hazardousdisinfectionby-products(DBPs)canbeproduced.ThebestknownoftheorganicDBPsarethetrihalogenmethanes(THMs).Theyhaveanindicatorfunctioninrelationtothehealthevaluationofpollutioninswimmingpoolwater.THMsalsoentertheairinindoorpoolsfromthespray.AirpollutionbyTHMscanbereducedbyeffec-tiveventilation.

RegardingtheassessmentoforganicDBPs,thereistodateinthefieldofswimmingpoolwateronlyacumulativevalueof0.02mg/lforTHMsinDIN


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19643,whichisbasedontechnologicalfeasibility.Inevaluatinghealthrisksarisingfromswimmingandbathingpoolwateritshouldbenotedthattworisksshouldbeweighedupagainsteachother,beingthemicrobiologicalandthetoxicological,wherebythemicrobiologicalshouldbeclassifiedasmorerelevantoverall.

Centraltoswimmingpoolwatertreatmentistheflocculation,filtrationandthechlorinationofthewater(DIN19643).Sometimesactivatedcarbonad-sorptionorozoningprecedesorfollowsflocculation.ExperiencesshowthatitistheflocculationandfiltrationprocessesthatarecarriedoutincorrectlyandthattherequirementsofDIN19643arenotmet.Thisalsoappliespar-ticularlytotheregularcleaningoffiltersthatisnecessary.

Incorrectwatertreatmentcanleadtopollutionofthepoolwaterwithpseudomonas aeruginosa (especiallyfollowingfiltercontamination)andtolegionella.Thereisanespeciallyhighriskofinfectioniftheshowersarecontaminatedwithlegionellabecausethehotwatersystemsaresetatalowtemperature.Schoolswhichoperateaswimmingpoolshouldincludetheservicingandcleaningofthepoolintheoverallhygieneplan.Inac-cordancewithDIN19643,specificmeasurestobeundertakeninthepoolregardingpoolwatertreatment,showersandcleaninganddisinfectionproceduresshouldbelaiddowninthehygieneplan.Theschoolshouldensurethatthestaffresponsibleforthepoolmachinerytakepartinregulartraininganddevelopmentinthisfield.TherecommendationsoftheFed-eralEnvironmentAgency’sSwimmingPoolWaterCommission(seeBun-desgesundheitsbl-Gesundheitsforsch-Gesundheitsschutz9,2006)andfurtherhygienerecommendations(e.g.poolhygieneplans)shouldalsobetakenintoaccounthere.

InafurtherrecommendationfromtheSwimmingPoolWaterCommission(Bundesgesundheitsbl1997)specialinstructionsforpreventingthecontrac-tionofwartsaftervisitingswimmingpoolsarebeingissued.Wartsarecausedbyviruses.Moreover,therearevarioustypesofwarts,whichcanoccurmostcommonlyonthebacksandpalmsofthehands,thefingers,andonthesolesofthefeet(verrucas).Molluscumcontagiosum(MC)causeslumpsfrompinhead-sizetothesizeofapea,withasmoothandoften

Thetreatmentofswimmingpoolwaterisatechnicallycomplexprocedurethatrequiresahighlevelofexpertiseinpooltechnologyonthepartoftherelevantoperators. In the case of school-run swimming pools this is often only barelyachievable,astheyhavenospecialiststaff.Thetechnicaloperationofthesepoolsisundertakenbytheschoolcaretakersorbylocalauthorityemployees,whomustbeexperiencedindealingwithmaintenanceandpoolmachinery.


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shinysurface,whichsometimeshasadipinthemiddle.Theycanoccuranywhereonthebody.MCistransmittedthroughdirecthumancontact(whenplaying,takingpartinsport,etc.),whereasnormalwartsaremainlytransmittedindirectly,throughcontactwithmaterialorobjectscontainingthevirus.

Infectiondoesnottakeplaceviathewater.

ChildrenandyoungpeopleshouldbeinformedaboutthecontagiousnessofwartsbyP.E.teachersorotherresponsiblepeople.Indoingthis,thefol-lowingpointsshouldbeemphasised:

Youshouldavoidsharingtheuseoftowels,massageoil,skinlotions,etc.amongseveralpeople.

Youshouldrefrainfromgoingbarefootinswimmingpoolsifyoualreadyhavewartsorverrucas.

Avisittothedoctorisrecommendedifyouhavewarts.

Whenuseoftheswimmingpoolisover,thesurfaceswalkedonwithbarefeetshouldbedisinfectedwithanactivevirucideinaccordancewiththelistofdisinfectantsfromtheGermanAssociationforHygieneandMicrobiologyortheRobertKochInstitute.Thescrubbingandwashingprocedureshouldbeusedforthis.Sprayingwithdisinfectantisnotsufficient,asflakesofskinarenotremovedeffectivelybythis.

A-5 Minor building works and renovations

Afterminorbuildingworks,maintenanceandrenovationstherearealwayscomplaintsfromteachers,pupilsandparentsaboutpoorindoorairquality.Problemswithindooraircanbelargelyavoidedwhenminorbuildingandrenovationprojectsarecarriedoutcorrectly.

Therearefouraspectstobeconsideredinrelationtoairhygienepriortobuildingandrenovationwork,inordertominimiselateremissions:

Choiceofmaterials

Quantityofmaterials

Monitoringoftheprogressandcompletionofthework

Coordinatingandmonitoringthetimeframe.

Buildingproductsandothermaterialsreleasevolatileorganiccompounds(VOCs)intotheairintheroom(cf.SectionB-2).Thiscanhavenegativeimpactsontheusersoftheroom.Theextentofthesedetrimentaleffects


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dependsonthetypeandintensityaswellasthedurationoftheVOCemis-sions.Particularlythosematerialstobeusedoverlargeareasintherooms,suchassurfacecoatings,bondings,andfloorcoveringsshouldbechosensothattheminimumofemissionsareproducedafterinstallationandduringlateruse.

InthecontextoftheseGuidelinesitisnotpossibletogivealistofbuildingproductsanddecoratingmaterialstoberecommendedonahygienebasis,asthereisavastarrayofproductsonthemarket,whichissubjecttore-gionalvariationandwillchangeovertime.IntheSafetyDataSheetsfortheproductsthemanufacturersandsuppliersmustlist,amongstotherthings,substancessubjecttolabellingregulations.InstructionsforuseandfurtherproductinformationcanbefoundintheTechnicalDataSheets.Forthemostpartthereisinsufficientinformationonemissionsbehaviourinthesedatasheets.TheIndoorAirHygieneCommissionrecommendsgivingprior-itytomanufacturersandsuppliersofbuildingproductsandothermaterialswhorespondtoconsumerdemandformoredetailedinformation.

ProductsmarkedwiththeBlueAngelecolabel“lowinemissions”or“lowinhazardoussubstances”producelowlevelsofemissionsandshouldprefer-ablybeused.Theleaflet“UmweltzeichenfürBauprodukte.Bauproduktegezieltauswählen”[Ecolabelsforbuildingproducts.Howtochoosetherightbuildingproducts]offersadviceonproductselection.Thisisavail-ableatwww.apug.nrw.de/pdf/Bauprodukte.pdf.Unfortunately,productsbearingtheBlueAngelandotherenvironmentallabelsarenotyetavailableforallareasofapplication.

Odourspresentamajorprobleminthechoiceofbuildingmaterials.Manybuildingproductsarenotodour-free,especiallywhentheyaredeliveredfreshfromthefactory.Theseodourscanthenpersistinthefirstfewmonthsafterinstallationandleadtounpleasanteffectsfortheusersofthespace.Atpresentitisnotpossibletogaugehowmuchodourpollutionarisesfrom

Beforestartingminorbuildingworks,maintenanceandrenovationsanoverviewof the type and amount of substances contained in materials needed for thebuildingandrenovationworkshouldbeavailabletotheappropriateoffice.Ini-tialinformationonthiscanbefoundintheTechnicalDataSheetsandtheSafetyDataSheets.Furtherdetailscanbeobtainedfromthemanufacturerorsupplier.Somemanufacturershavecommissionedstudiesintotheemissionsbehaviouroftheirproductsandcanprovideinformationonit.ProductswiththeBlueAngelecolabelshouldpreferablybeused.

What should be considered when choosing materials?


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products,evenbyonlychoosingthebestmaterials,forexamplethosetestedinaccordancewiththeAgBB[CommitteefortheHealthEvaluationofBuild-ingProducts]scheme(fortheAgBBschemeseeSectionC-1)andapprovedbytheDeutschesInstitutfürBautechnik[GermanInstituteforConstructionEngineering].Thetestconditionscurrentlyonlyincludeananalysisofvola-tileorganiccompounds(VOCs,seeSectionB-2)andsemi-volatilecompounds(SVOCs,cf.SectionB-4).Variousstudieshaveshownthatthereisnocor-relationbetweenVOCemissionsandodouremissions.Infutureodoursarealsotobeincludedinevaluationsbasedonthescheme.Therehavebeeninitialexperimentswithaprocessfortheodourevaluationofconstructionproductsonthebasisofmeasurementstakenintestchambersformeasur-ingemissions(cf.Furtherreading“Bauprodukte:SchadstoffeundGerüchebestimmenundvermeiden”[Buildingmaterials:identifyingandavoidinghazardoussubstancesandodours]inSectionIII).Thisprocess,whichisbasedontheevaluationofodourintensitybyatrainedpanel(agroupofpeoplespeciallytrainedtorecogniseodours)withtheaidofastandardofcompari-son,hasproveditssuitabilityandgoodreproducibilityinaroundrobintest.Asithasnowgainedgeneralacceptancethisprocessiscurrentlyundergo-inginternationalstandardisation(ISOTC146/SC6).

Theproductsandmaterialsselectedandusedshouldnotonlybelowinemissions,butshouldalsobeasdurableaspossible.Everyextensionintheperiodofusepostponesmorebuildingorrenovationworkwiththepoten-tialtoreduceindoorairquality.

Theselectionanduseoflow-emissionconstructionproductsisonecriterionforavoidinghazardousemissions,whiletheotherison-sitemonitoringwhethertheseproductsareindeedbeinginstalledintheschoolbuildingintheproperway.Propersupervisionoftheworkbyaprojectmanagerorcomparableexpertfamiliarwiththeindoorairhygienerequirementsisthereforetobestronglyadvised.

Inthecaseoflayeredconstructionoffloorsandotherlargesurfacescareshouldbetakentocarryouttheseparatestagesinsuchawaythatthesolventsandotherauxiliaryvolatilematerialsusedevaporateasfullyaspossiblebeforethenextlayerisapplied(seemanufacturer’sinstructions).Particularlyinthecaseofabsorbentproductsandproductscoveringlargeareas,orthecorrespondingsubsurfaces,itisessentialtoensurethatnooronlysmallquantitiesofvolatileorganiccompoundsareingested(e.g.byapplyingasuitablebarrierlayer)fromsubsequentstagesofworkandduringlatercleaningprocedures.

Theformationofsubstancedepositsbetweenlayersshouldbeavoidedifpossible.Forthesamereasonproductscontainingvolatilesubstancesshouldnotbeallowedtopenetrategaps,cracksandcavitiesinlargequantities.


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Careshouldalsobetakenduringrenovationstoensurethattheexistingsubsurfaceandresiduesofoldmaterialonitdonotreacttothenewprod-uctsinawaythatcouldforexampleleadtoodourpollution.Theapplica-tionofasuitablebarrierlayercanpreventreactions.

TheemissionofVOCsandSVOCsfromconstructionproductsanddecoratingmaterialscanbeconsiderablyrestricted,butnotcompletelyavoided.IndoorairisalmostalwaysadditionallycontaminatedbyVOCs(lessbySVOCs,whichreleasegasmoreslowly)immediatelyafterbuildingandrenovationwork.Forthisreasonacertainlengthoftimeshouldbefactoredin(thiscantakefromonetoseveralweeks,dependingontheextentandtypeofreno-vationwork)fortheVOCstoescapebeforeusingtheroomsagain.Inschoolsitisagoodideaforminorbuildingworksandrenovationstobescheduledforthebeginningoftheschoolholidays,sothatmostofthecomponentshavealreadybeenreleasedfromthematerialsbeforetheroomisusedagain.Whiletheoffgassingofthesubstancesistakingplacetheremustbeintensiveventilation.

Ifhotwaterpipesandradiatorshavebeennewlypainted,itisstronglyrecommendedtoruntheheatingsystembrieflywhenthepaintisdrywithnobodyintheroom.Thiswillallowcompoundsthatonlyoccurinthepaintlayerathighertemperaturesandoftengenerateunpleasantodoursandirritationstobereleasedfromthepaintlayerasfaraspossibleingoodtimebeforethelaterusephase.

Oncetheconstructionandrenovationworkiscompletetheentirebuildingshouldbeintensivelycleaned.Cleaningwithwaterandthemostthoroughpossibleremovalofalldustdeposits,whichmaylateractas“long-termstor-age”forsemi-volatileorganiccompounds(cf.SectionB-4)emittedduringtherenovation,isstronglyadvised.

Check whether the products selected are actually used in the project. Ifnecessary, checkwhether thematerialsdeliveredcomplywithallqualityrequirements(includingemissionsbehaviour).

Checkwhetherthematerialsselectedareunloadedproperlyandinsuffi-cienttime,ifthisisspecifiedinthechoiceofmaterial.

Checkwhethertheworkinginstructionsandadvicefromthemanufacturerarebeingfollowed.

Checkwhetheradequateventilationandevaporationtimeisbeingallowedwhenlayingandfixingmaterials.

What hygiene implications can and should an on-site project manager consider during renovation work?


32

A-6 Workshops, laboratories and home economics practical areas

Workshops,laboratoriesandhomeeconomicspracticalareascountasspecialteachingareasusedonlyforthesepurposes.Therecanbeparticu-larproblemshere,forexamplewhencarryingoutexperimentsinvolvingsmokeproduction,whichdonotoccurinnormalclassrooms,oratanyratenotinthisform.Extensiveregulationsexistfortheseareas,includingintheOrdinanceonHazardousSubstancesandtheGermanFoodLaw,whichwillnotbediscussedfurtherintheseGuidelines.Inthefollowingsectionpos-siblepollutionsourcesandexistingregulationswillbereferredtobriefly.

Workshops

Ventilationrequirementsforschoolworkshopsarelaiddowninthe“RegelnfürSicherheitundGesundheitsschutzbeimUmgangmitGefahrstoffenimUnterricht”[Healthandsafetyrulesfordealingwithhazardoussubstancesinlessons](GUV19.16edition.January1998,clause5.2).Inaccordancewiththeseadequateventilationmeasuresarerequired,amongstotherthings,whenworkingintechnicalsubjectsandinartlessons,ifhazardoussub-stancesarebeingusedorcouldbereleasedintotheairintheroomduringthelesson.Whenweldingistakingplaceair-conditioningmeasuresarenec-essary,whilefornormalsolderingnaturalventilationisgenerallysufficient.Inthecaseofwoodworklow-dustworkingconditionsmustbecreatedintheworkshops.Thiscanbebestachievedbyensuringthat:

thedailyexposureremainsbelowhalfanhourperschooldayandthewoodworkmachineryisonlyusedforafewdaysayear.

thesawdustfromstandardwoodworkingmachineryisvacuumedupatthepointofproduction.

thewoodworkingmachineryisfittedwithdustcollectingunitsandcertifieddustextractors.

Laboratories

Areasusedforsciencelessons,suchaschemistrylaboratories,mustbeequippedwithatleastonefumecupboardinaccordancewithGUV19.16.Thefumecupboardsmustensurethatgases,vapours,smoke,fumesanddustparticlescannotescapeintotheclassroomfrominsidethecupboardinhazardousconcentrationsorquantities.Adangerousexplosiveatmospheremustnotbecreatedinsidethefumecupboard.Aslidingfrontpanelmustbeclosedtoprotectpeople,incasehazardoussubstancessplashorglassshatters.


33

Home economics practical areas

KitchenscomeundertheBerufsgenossenschaftlicheRegel[professionalassociationrule](BGR111;previouslyZH1/37)“RegelnfürSicherheitundGesundheitsschutzbeiderArbeitinKüchen”[Healthandsafetyrulesforworkinginkitchens].Homeeconomicsteachingroomsarealsolistedasareastowhichitapplies,buttherulesshouldbeappliedinsenseonly,bearinginmindtheschoolsituation.Accordingtotherules,duringwork-ingtimesairandroomtemperatureconducivetohealthmustbeprovided,takingintoaccounttheworkbeingundertakenandthephysicaldemandsoftheworkers.Forequipmentlikelytoproduceincreasedvapourandcook-ingfumes,e.g.kettles,tiltingfryingpans,anddeep-fatfryers,anextractorhoodisrequired.Duringboiling,fryingandbakingtinyparticlescanbereleased;todatetherehasbeenlittleornoresearchintotheirhygienicimportance.Tobeonthesafeside,cookingprocessesofthissortshouldbecarriedoutundertheextractorhood.Largequantitiesofnitrousoxidecanarisethroughtheuseofgasstovesforcooking.Insuchcasesgoodventila-tionshouldbeprovidedinadditiontotheextractorhood.

Blowcleaningandsweepingraisessawdustresiduesandisabsolutelyprohibited.Sawdustmustalwaysbevacuumedupbymachine.

Whenworkinginspecialisedteachingareasparticularcareisneededforthepro-tectionofpupilsandteachers.Thecurrentregulationsmustalwaysbeobserved.Fumecupboardsshouldbeinstalledinsufficientnumbersandmustfunctionper-fectly.Regularmaintenanceandinspectionsofthecupboardsisessential.Whenusinghazardoussubstanceschecksmustbemadetoseewhetheralternativesub-stances,preparationsorproductswithalowerorpreferablynohealthriskcanbesubstituted.Contactwithcarcinogenic, suspectedcarcinogenic,mutagenicandreprotoxicsubstances(CMRsubstances)shouldnottakeplaceinanyschoolsub-ject.Theexceptionsareonlyteachingexperimentsinwhichtheintentionistostudythereactionofsomesubstanceswithothers.Thissortofexperimentmayonlybeconductedbytrainedteachingstaff(asademonstrationexperiment)andmusttakeplaceinthefumecupboard.Dependingontheexperimentadditionalindividualsafetymeasuresmayneedtobetaken(thewearingoffacemasks,pro-tectiveglassesandgloves,labcoats).

What should generally be taken into account when working in workshops, laboratories and home economics kitchens?


34

A-7 Copiers, printers and PCs

Recentlytherehasbeenanincreaseinpressreportsthatindoorairpol-lutionfromvolatileorganiccompounds(styrene,benzeneetc.)aswellasfromsuspendedparticulatematterandultra-fineparticlescanbereleasedbycopiersandprinters.

TheFederalEnvironmentAgencyandtheUniversityofGiessenalsoestab-lishedina2007studythatultra-fineandfineparticlesareemittedwhenlaserprintersareused.Theresultsareavailableat:http://www.umweltdaten.de/publikationen/fpdf-l/3016.pdf andathttp://www.bfr.bund.de/cd/8644). VOCs are also released.

Theexactcompositionoftheparticlesreleasedbyprintersduringoperationisasyetunclear.ThelatestresearchattheUniversityofGiessenandotherinstitutionshasshownthattonerparticlesmakeuponlyasmallfractionoftheparticleemissions.Furtherstudiesareneededforclarification.

Owingtotheelectrophotographicprocess,ozonecanbeproducedduringtheoperationofcopiersandlaserprinters.Theamountsofozonereleasedaredependentonthetechnicalpropertiesofthemachine,thelengthofoperationandtheconditionofthemachines,aswellasthesizeoftheroominwhichtheyareinstalled.However,significantconcentrationsofozonehardlyoccuranylongerwithmodernmachines.Newermachines(sinceabout1992)arefittedwitheffectiveozoneadsorbers.

Thereisoftendiscussioninthepublicdomain,inrelationtoofficemachin-ery,abouttheuseandpossibleemissionfromfireretardants.Forfiresafetyreasonsplasticsusedinelectronicsforcasings,circuitboardsandcableinsulationaretreatedwithfireretardants(particularlyhalogenatedorganiccompounds).Halogenatedfireretardantsmaynotbepresentinmachinerywithanecolabel.

CopiersandlaserprinterscanemitsmallquantitiesofVOCsandparticlesduringoperation.Thereisapossibilityofbrieflycontaminatingtheairintheroomwhenthetonercartridgesarechanged.Forthisreasontonercartridgesshouldonlybechangedbydesignatedstaffandwithgreatcare.Larger,frequentlyusedprinters(“centralprinters”)andcopiersshouldbehousedinseparateroomswiththeirownventilationsystem.Whenpurchasingaprinteronlymachineswith theecolabel(RAL-UZ122)shouldbeconsidered.AdviceonpurchasingandoperatingprintersisalsocontainedintheFederalInstituteforOccupationalSafetyandHealth’srecom-mendations (available at: www.baua.de/nn_5846/de/Publikationen/Faltblaetter/F44.html?__nnn=true)

Are concentrations of substances harmful to health emitted by copiers, laser printers and other electronic equipment?


35

PART B: Contaminants in the indoor air in schools

Inthefollowingsectionsthesourcesofindooraircontaminationwillfirstbeexaminedandtheirhygienicimportanceinsideschoolssubsequentlydescribed.

B-1 Inorganic gases Table1givesanoverviewofimportantsourcesofinorganicgasesinindoor

air.Withtheexceptionofozonetheseinorganicgasesareproducedbyburningfossilfuels.Carbondioxideisalsoreleasedthroughbreathing.

Carbon dioxide(CO2)arisesthroughburningorganicmaterialsandisreleased

throughbreathing.Thecompoundisofparticularimportanceinschoolclassrooms,ashere–asinotherenclosedareasthataredenselyoccupied–alargenumberofpeoplecometogetherinarestrictedspace.Aslongas150yearsagothehygienistMaxvonPettenkoferdrewattentiontothefactsof“bad”airwhenalongtimewasspentinlivingspacesandeducationalestablishmentsandidentifiedcarbondioxideasanimportantindicatorinassessingindoorairquality.ForalongtimethePettenkoferNumber0.1volumepercent(=1000partspermillion(ppm))wasregardedastheevaluationyardstickinindoorspaces.BycomparisontheCO

2contentof

outsideairisaround350ppm(intownsinsomeplacesevenuptoaround500ppm).

TheadhocworkinggroupoftheIndoorAirHygieneCommissionandtheWorkingGroupoftheSupremeHealthAuthoritiesoftheFederalStates(IRK/AOLGadhocworkinggroup)hasproducedanevaluationforcarbondioxideinindoorair(Table2)(Ad-hocAGIRK/AOLG,2008:Gesundheitli-cheBewertungvonKohlendioxidinderInnenraumluft[Healthevaluation

Table 1: Sources of relevant inorganic gases inside schools

Compound Source

Carbon dioxide (CO2) People,nakedflames

Carbon monoxide (CO)Experiments with incomplete combustion of organicmaterials,homeeconomicskitchens,outsideair

Nitrogen dioxide (NO2)

Homeeconomicskitchens (gascooker),Bunsenburn-ers,outsideair

Ozone (O3) Outsideair(summer),copiers,laserprinters


36

ofcarbondioxideinindoorair],Bundesgesundheitsbl-Gesundheitsforsch-Gesundheitsschutz(inpress)).Accordingtothis,guidevaluesforcarbondioxideconcentrationsinindoorairarelaiddown,whicharetobeseenassnapshotvaluespertainingtotheconcentrationatagivenmomentintime.Itisdividedinto“hygienicallyinsignificant”(CO

2<1000ppm),

“hygienicallyevident”(CO21000–2000)and“hygienicallyunacceptable”

(CO2>2000ppm).IfaCO

2valueof1000ppmisexceededtheroomshould

beaired,andif2000ppmisexceededitmustbeaired.Inbothcasestheaimshouldbetoremainbelow1000ppm.Ifthesituationcannotbeim-provedinthelongtermbyairingalone,air-conditioningmeasuresshouldbeemployedorthenumberofpupilsintheclassroomshouldbereduced.

Table 2. Guide values for carbon dioxide concentration in indoor air (Ad hoc working group 2008)

Co2 concentration [ ppm] Hygiene rating Recommendation

<1000Hygienicallyinsignificant

Nofurthermeasures

1000–2000Hygienicallyevident

Intensifyventilationmeasures(increasevolumeofairflowfromoutsideorairexchange).

Checkandimproveventilationprocedures

>2000Hygienicallyunacceptable

Checkventilationpossibilitiesandifnecessarycheckexten-sivemeasures

Theconcentrationofcarbondioxideinindoorairdependsonthenumber,lengthoftimespentandactivityofthepeoplepresentaswellasontheconstructiondetails(volumeoftheroom,airexchangenumber,etc.).Al-thoughtheproblemofcarbondioxideinroomscontainingalargenumberofpeoplehaslongbeenknown,todatenoconvincingsolutionshavebeenfoundforschools.Atthesametimetherearenoclearregulationsregard-ingresponsibility,especiallyinthewintermonths,abouthow,whenandbywhomtheclassroomwindowsshouldbeopened.Asistobeexpected,thisresultsinhightoveryhighCO

2values(3000ppmandabove),butalsoin

anincreaseinotherindoorpollutantsandwatervapour.ThereisanurgentneedtodevelopideasformeetingtheguidevaluesgiveninTable2.


37

Toassistschoolsonecouldenvisageasensor-driventrafficlightwhichchangesfromgreentoambertoredifspecificCO

2valuesareexceededand

indicatestheneedforactioninaccordancewithTable2.Themeasuringin-tervalforthesensor-operatedsystemshouldalsobeverycarefullyselected,inordertopreventthereadingfromchangingconstantlyfromonetoanotherduringoperationandthusmakingtheactiontobetakenunwork-able.Ameasuringintervalofatleast2minutesisrecommended.

Ifnaturalairexchangeviaopenwindowsisimpossible,air-conditioningmeasuresmustbeintroducedinordertokeeptheCO

2concentrationsata

lowlevel.

Until2005aCO2valueof0.15vol.-%(=1500ppm)inaccordancewith

DIN1946Part2appliedastheguidelinehygienevalueinGermanyinschoolswithair-conditioninginstallations.InJuly2005DIN1946-2wasreplacedbyEN13779,whichwasamendedinSeptember2007.ThisENcontainsrecommendationsforplanningandinstallingair-conditioningsystemsinallnon-residentialbuildingsintendedforhumanoccupation.Indoorairissubdividedintofourqualitylevels(IndoorAir1to4).Differ-entventilationratesperpersonorperm2floorareaarederivedfromthesequalitylevels

Wearenowundoubtedlyonthethresholdofacertainparadigmshiftinthoughtand action. The current situation in many schools shows that in many placestheCO

2problemcannolongerbebroughtundercontrolthroughrequestsfor

regularandintensiveventilationalone.Air-conditioningmeasuresthenbecomeessential in order to achievepermanenthighquality airwith a lowCO2 con-centrationwithoutdependingonhumanintervention.Regularservicingandin-spectionsofthesystemarenecessary,sothatthisdoesnotitselfleadtohygieneproblems.

Fresh air through windows or ventilaion systems in schools?


38

Carbon monoxide(CO)isreleasedduringtheincompletecombustionoffossilfuels.Onbusyroads,especiallyinconurbations,italsopenetratesindoorspaceswiththeoutsideairduringventilation.Tobaccosmokerepresentsanotherconsiderablesourceofemissions.Preventingtheoccurrenceofcarbonmonoxideisyetanotherreasontoemphasisethegeneralsmok-ingbaninschools.COcanalsoentertheindoorairthroughusinggasforcookinginhomeeconomicskitchens–however,onlywhereairextractionisinadequate.Carbonmonoxideimpairsthetransportofoxygenwithhae-moglobin.However,theconcentrationsnecessaryforthisarenotnormallytobeexpectedinschools.

Nitrogen oxides(NOx=sumofnitricoxide(NO)andnitrogendioxide(NO2))

enterindoorairmainlythroughburninggas(Bunsenburnersinlaborato-ries,gascookersinhomeeconomicsrooms),apartfromcominginfromoutside.Thiscanbelargelyavoidedbysuitableairextractionwhencookingwithgasinhomeeconomicsrooms.Short-livedraisedconcentrationsofNO

2inindooraircanalsoarisefromtheuseofoilinlampsorlargernum-

bersofcandles.Withprolongedhighlevelsofexposure,nitrogendioxidepromotestheonsetofdiseasesoftherespiratorytracts.

Table 3. Classification of indoor air quality in accordance with DIN EN 13779: 2007-09. The table contains the regulations from DIN EN 13779 in columns 1 to 3. Column 3 shows the relation of the CO

2 concentration in indoor air to the total CO

2 concentration. Column 4 indicates the absolute CO

2

concentrations in indoor air for an outside air CO2 concentration of for example 400 ppm.

Category Description Increase in CO2

concentration compared with out-side air [ppm]

Absolute CO2

concentration in indoor air [ppm]

Ventilation rate/ outside air flow volume [l/s/person] ([m3/h/person])

IDA 1Highindoorairquality

≤400 ≤800>15(>54)

IDA 2Mediumairquality

>400–600 >800–1000>10–15(>36–54)

IDA 3Moderateindoorairquality

>600–1000 >1000–1400>6–10(>22–36)

IDA 4Poorindoorairquality

>1000 >1400<6(<22)


39

Ozone(O3)canbeemittedintoindoorairinschoolsthroughtheuseofcopi-

ersandlaserprinters,oringeneralfrommachineswhichhavesourcesofUVrays(cf.SectionA-7).Modernofficeequipmentgivesoffsolittleozonethateveninsensitivepeoplebreathingdifficultiesandimpairmentsinlungfunctiondonotoccur.

Inhighsummerweatherconditionsozoneformedintheairoutsidealsoentersindoorspacesthroughventilation.Ingeneralozoneisquicklybro-kendownintheindoorenvironment.

B-2 Volatile organic compounds (VOCs)

Volatileorganiccompounds(VOCs)representagroupofairpollutantsubstancesthatpracticallyalwaysoccurinindoorair.VOCsarecharacter-isedasagroupofverydiversesubstancesbytheirboilingpointanddis-tinguishedfromtheveryvolatile,semi-volatileandnon-volatileorganiccompounds.Accordingtoconventionorganochemicalcompoundswithaboilingpointof50–100oCto240–260oCaredescribedasvolatileorganiccompounds(VOCs)(WHO1989).Inanalyticalpracticeorganiccompoundswhichcanbedeterminedintheelutionrangebetweenn-hexaneandn-hexadecanearedescribedasVOCs.Thesumofthevolatileorganiccompoundselutedbetweenn-hexaneandn-hexadecanearedesignatedTVOCs(totalvolatileorganiccompounds).Semi-volatileorganiccompounds(SVOCs)areorganiccompoundsthatlieintheretentionrangeaboven-hexadecaneuptoC

22,andveryvolatileorganiccompounds(VVOCs)those

thatappearbelown-hexane.Table4givesanoverviewofVOCsoftenrecordedinindoorspacesandtheirsources.


40

Inparticular,thefollowingVOCsareimportantforindoorareasinschools:

Alkanes and alkenes

Alkanesarestraight-chainsaturatedcompounds(aliphates)whicharedistinguishedbythenumberofcarbonandhydrogenatomsinthemol-ecule.Afterrenovations,butalsoaftercleaningofclassrooms,thegroupofnonanetotetradecane(9and14carbonatomsrespectivelyinthemolecule;C-9andC-14,respectively)isfoundespeciallyfrequentlyintheindoorair.Inunfavourablecircumstanceslightheatingoiltankscanbecomesourcesofalkanesinthegroupbetweentetradecane(C-14)andoctadecane(C-18).Thisgroupofalkaneswithboilingpointstoover300oCissometimesalso

Table 4: VOCs often recorded in indoor spaces and their sources; 1) except formaldehyde, which belongs to the VVOC group

VOCs and VOC groups Sources

Alkanes, alkenes and cycloalkenes

Outdoorair,motorisedtraffic,fuels,solvents(solventnaphta)invarnishes,resinsandstainremovers

Aromatic compoundsVehicleemissions,cigarettesmoke,solvents,carpetbackside(e.g.Phenylcyclohexene),foamproducts

TerpenesWood,solvents,“odourimprovers”,fragranceadditivesz

NaphthalenesBitumentiles,taradhesives,tarredfelts,mothrepellent

AlcoholsCleaningproducts,solvents,sub-productsfrome.g.plasticizers

Aldehydes 1)

Kitchenvapour,disinfectants,alkydresinpaints,oilpaints,linoleumby-products,corkflooring,woodproducts

Ketonessolvents(e.g.Methylethylketone),metabolites,sealcoatedsurfaces

EstersSolvents,softeners,heatingcostsdistributor(methylbenzonate)

Glycol ethersSolventsinwatersolublepaintsandvarnishes,cleaningproducts

Halogenated compoundsDegreasing,solvents,drycleaning(tetrachloro-ethene),Tippex(1.1.1-trichloroethane),toiletblocks(p-dichlorobenzol)

Other compoundsBondingagents(phenol),disinfectants(cresols),sealingcompounds(butanonoxime)


41

usedassolventsand,sincestrictlyspeakingitdoesnotbelongtotheVOCgroup,isonlymentionedforthesakeofcompleteness.Thisapplieslikewisetotheveryvolatilen-alkanes,suchasmethane(C-1)andbutane(C-4),whichareconstituentsofnaturalgasandarenotgenerallymeasuredwiththeusualindoorairanalysismethods.

Alkenes(olefins)areunsaturatedhydrocarboncompounds.Longstraight-chainolefincompoundsrepresentreagentsandby-products.Saturatedcy-clichydrocarbonssuchascyclohexaneandmethylcyclohexaneareusedassolventsinvarnishes,resinsandstainremoversintheindoorenvironment.

Aromatic compounds

Aromaticcompounds(arenes)arehydrocarboncompoundswithaclosedringstructure,inwhich,incontrasttosimplecycliccompounds,particularbondingpropertiesexistbetweenthecarbonatomsinthering.Inschoolspracticallytheonlysourceofbenzene,thebasicsubstanceinthearomaticgroupwith6carbonatoms,whichistoxicologicallyparticularlysignificantbecauseofitscarcinogeniceffect,istraffic-pollutedoutsideair(upto1%benzeneispermittedinfuel).

Inthepasttoluenewasfrequentlyusedasasolvent.Nowadayshigheraromaticcompoundswith8carbonatomsandmore(calledalkylarenes)areusedinplaceoftoluene.Theseoftenalsohaveanobviousodour.Thisisalsothecasewithstyrene,whichishoweverrarelyencounteredinschools.Polynucleararomatichydrocarbons(e.g.naphthalene,indenes)arealsogenerallyoflittlesignificanceintheindoorairinschools,exceptthatbitu-menandcoaltarproductswereusedinflooringconstruction,forexample(moisturestop,woodblockflooradhesive);compoundsofthatkindarethenreleasedintoindoorair.

Terpenes

TerpenesrepresentanimportantgroupofVOCs.Themonoterpeneslimonene,α-andβ-pineneandδ-3-carenearefrequentlyandincreasinglytobefoundinindoorspaces.Naturallyoccurringgasesfromwoodproducts,additionasfragranceanduseasa“natural”solventforvariousproducts(includingpaints,varnishesandwoodtreatments)aresubstantialroutesofentryintoindoorair.Terpenesarealsofoundincomparativelyhighconcentrationsinpreciselythosebuildingsandroomsconstructedorfittedaccordingtoenvironmentalprinciples,especiallyifwallsandceilingsarecladextensivelyinsolidpine.Variousterpenealcoholsandterpeneketones(e.g.geraniol,camphor)areintroducedintotheindoorairwithfragrances.


42

Alcohols

Apartfromethanol(alsocalledethylalcohol),colloquiallyknownas“alco-hol”,thereareothercompoundsbelongingtothechemicalclassofalcoholswhicharetobefoundinindoorair.Lowalcoholssuchasethanolorpro-panol,isopropanolundisobutanoloccurinverymanyhouseholdproducts(e.g.cleaningagents,solvents,disinfectantsandcosmetics).Asaresultofhydrolyticcleavageamongstotherthings2-ethylhexanol,analcoholwhichoccasionallycontributestoodourproblemsinindoorspaces,canentertheindoorairfromsoftenersandplastics.

Glycols

Glycolethersaretechnicalsolventsinfrequentuse,especiallyinvarnishes,dyesandprintinginks,stampingink,wallpaints,water-basedenamelsandballpointpenpastes,andareregularlydetectedinindoorair,sincetheyareusedassubstitutesfortheclassicaliphaticandaromaticsolventsmentionedabove.EvenenamelsdisplayingtheBlueAngellabelmaycontainupto10%glycolcompounds,andglycolcompoundswithboilingpointsabove200oCareusedinso-calledsolvent-freecarpetadhesives.Glycolsandglycolethers(suchas2-buthoxyethanol,phenoxyethanolanddiethyleneglycolmonoethylether)arepolarcompoundswithboilingpointsabove120oC.Onaccountoftheirrelativelyhighboilingpointtheycanbeemittedfromsurfacesoverlongperiods(months).

Aldehydes

Incontrasttothehigheraldehydes,thesimplestrepresentativeofthissub-stancegroup,formaldehyde,doesnotbelongtotheVOCgroup,buttotheVVOCs,onaccountofitslowboilingpoint.Becauseofitswidedistributionanditsimportancewithregardtohygieneaseparatesectionisdevotedtoit(seeSectionB-3).

Ofthestraight-chainaldehydesn-hexanalinparticularoftenoccursinindoorair.Importantsourcesarealkydresinpaintsandvarnishes.

Inthecourseofdrying,interlacingandalsotheoxidativedegradationoftheoil-basedbinders,thealdehydesaresplitoffandreleased.Sincelino-leumalsocontainsoil-basedbinders,aldehydescanbegivenoffintothesurroundingairfrompoorlymaintainedlinoleumfloors(cf.SectionA-2).Benzaldehydeisfoundasafragrance(likebitteralmonds)inperfumeditems.

Furfuralisanaldehydewitharing-shaped(cyclic)molecularstructure,whichcanentertheindoorairifusedinpressedcorkproducts(e.g.floor


43

tiles).Propanal(acrolein)isoneoftheunsaturatedaldehydeswithaparticu-larlypungentodour.Onewayinwhichthecompoundisproducedisinthethermaldecompositionoffats(cookingvapour).

Ketones

Butanone(methylethylketone–MEK)andhexanone(methylisobutylketone–MIBK)aresolventswithvarioususes,e.g.inall-purposeadhe-sives,andcanenterindoorairasthegluedriesout.Cyclohexanoneandacetophenoneareoccasionallygivenoffintotheindoorairfromsurfacecoatings.

Esters

Estersarefrequentlyusedsolvents:ethylacetate,butylacetateandisobutylacetatecanoccurinindoorair,particularlyafteralterationsandrenovationwork.Texanolisusedasanadditiveforvarnishes,woodfloorsealantsanddispersionpaints(latexpaints),andink-jetprinterinks,toimprovethefilmformation.Mixturesofestersandalcoholsarecomingontothemarketinincreasingquantities.Water-basedpaintscancontainsuchmixturesandgiveoffthecorrespondingcompoundsintotheindoorair.EsterTXIB(texa-nolisobutyrate)isnowusedasasubstituteforsofteners(cf.SectionB-4).

Halogenated organic compounds

Overthelasttenyears,concentrationsofpracticallyallhalogenatedorganiccompoundsinindoorairhavebeenfalling.Halogenatedorganiccompoundssuchas1.1.1-trichlorethaneusedtobefoundinthingssuchas“Tipp-Ex”fluids(useprohibitedsince1991).Othersubstancesandareasofusearep-dichlorobenzenefromtoiletdeodorantblocksandmothrepel-lents,strong-smellingmono-totrichloronaphthalenesfromwood-basedmaterialstreatedwithfungicides,andchloranisolsasdecompositionprod-uctsofwoodpreservatives.Ofsignificancewithregardtohygienearethehalogen-containingorganictrihalomethanesandchloramines,whichariseinindoorswimmingpoolsasreactionproductsfrompoolwaterchlorina-tion(cf.SectionA-4).

Siloxanes

Alsofindingincreasinguseassolventsinenamelsarevolatilesiliconcom-pounds,knownassiloxanes,suchasmethylpolysiloxanes(e.g.cyclopentasi-loxane),whichareoftendetectedintheindoorair.


44

Nitrogen and sulphur-containing organic compounds

Manyamines,anilinesandotherbasicorganiccompoundsareusedasproductauxiliaryagents.Theyareveryseldomdetectableinindoorairandmostlyhaveanoticeableodour.Dimethylformamidecanbegivenoffinsmallquantitiesintoindoorairfromacrylicfabric,andalsopossiblyfrommouldedlaminatedplasticparts.Sulphur-containingorganiccompoundsareusedforexampleasanodouradditive(sothatescapinggasissmelt)intownandnaturalgas.

Microbial volatile organic compounds (MVOCs)

Whenmouldgrowthoccursasaresultofdampdamageinindoorspaces(cf.SectionB-7)volatilemetabolicproductsofmicro-organisms,e.g.variousalcohol,aldehydeandketonecompoundscanenterindoorair.Someofthesemicrobiallyproducedvolatilesubstancesarelargelyspecifictomicro-organisms,whileotherscanalsoarisefromvariousothersources,suchassometerpenesoraromatichydrocarbons,liketoluene,forexample.ThesubstanceswhichshouldbeassignedmainlytomicrobialsourcesarecalledMicrobialVolatileOrganicCompounds(MVOCs).MVOCscanbemeasuredinindoorairbyspecialmethodsandusedasindicatorsforthepresenceofmicrobialdamage.IngeneralMVOCsarepresentinindoorspacesinsignificantlylowerconcentrations(lessthan1μg/m3)thanVOCs.However,owingtotheirlowodourthreshold,theycanproducenoticeableodours(seefollowingparagraph).Especiallyinthecaseofmouldgrowththatisnotimmediatelyvisibletothenakedeye,MVOCreadingscanbehelpfulinidentifyingthedamage(cf.SectionB-7).

RiskstohealthcannotbededucedfromcontaminationwithMVOCs.TheindicatoreffectofMVOCsisthesignificantpoint,andunusualreadingsshouldbeseensolelyasgroundsforacarefulsearchforhiddenmicrobialsources.

Odour active volatile organic compounds (OVOCs)

Mostvolatileorganiccompoundsdonotproducenoticeableodoursinnormallowindoorairconcentrations.Odouractivesubstances,whichexudeanoticeableodoureveninverylowconcentrationsandasaresultpossiblyalsooverafairlylongperiod,areknownasodouractivevolatileorganiccompounds(OVOCs).Theyhaveamolecularweightbelow300g/mol,arelativelylowboilingpointandeasilyenterthegasphase.Theyoftencontainpolarfunctionalgroupssuchashydroxylorcarbonylgroups,orheteroatomssuchassulphurornitrogen.Referencehasalreadybeenmadeinthepreviousparagraphstosomeexamplesofodouractivevolatile


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organiccompounds,suchasterpenes,2-ethylhexanol,aldehydes,ketones,esters,halogen,nitrogenorsulphur-containingorganiccompoundsandafewMVOCs.Acompoundofanewertypeisbutanonoxim,whichcanbegivenoffintotheindoorair,forexampleduringthehardeningofsealants.OVOCspresentamajoranalyticalchallenge,astheycanalreadyreleaseanoticeableodourinconcentrationswellbelowthenormalrequiredlimitof1μg/m3,andOVOCsareoftennotdetectedwithroutineVOCmonitoring.

BecauseofthemanydifferentVOCsitisparticularlydifficulttocarryoutacomprehensivehealthevaluationforthissubstancegroup.ManyVOCscancausenervedamageintheveryhighconcentrationsthatoccurincommer-cialworkplaces,althoughnotinschools.SomeVOCscantriggerinflam-mationoftherespiratorytract,asirritantby-productsareformedinthemetabolismofthenasalmucousmembrane.

Whetherasensitisationcanariseisamatterfordebate.SomeVOCsexhibitverylowodourthresholdsandcanthereforebesmeltintheindoorair.Insomecasestheodourthresholdsaresolowthatthesubstancescanbesmelt,andyetcannotberegisteredwithcertaintyusingtechnicalmeasur-ingmethods(seecommentsabove).

Furthermore,thetoxicpropertiesdescribedintheliteraturerelateasaruletoindividualsubstancesandtohighconcentrationsthatcouldgenerallyonlyoccuratspecificworkplaces.However,intherangeofconcentrationsthatalsoarisein“normal”indoorenvironments,non-specificcomplaintsandsymptomsareoftenassociatedwithexposuretoVOCs.Theseincludeirritationsoftheskin,eyes,mucousmembranesandrespiratorytracts,headaches,fatigue,poorconcentrationandmajorproblemswithunpleas-antodours.

TheevaluationofVOCconcentrationsinindoorairdependstoalargeextentontheaccuracyofthemeasuringcarriedoutpreviously.Beforemeasuringisundertakentheaimofthemeasurementmustbedefined.

EspeciallyafterbuildingandrenovationworkincreasedamountsofVOCsenterindoorairforashortperiod(fromdaystoseveralweeks).Raisedconcentrationscanbereducedbytheselectionofappropriatebuildingmaterialsandproducts,andthroughintensiveventilationduringandoncompletionofthework.VOCemissionscannotbeavoidedentirely.OwingtotheirdiversefieldsofuseVOCscanpracticallyalwaysbefoundinindoorair.Regularventilationistheprincipalmeansofloweringconcentrations.

How can the release of volatile organic compounds into indoor air be avoided?


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Checkingthataguidelinevalueisbeingadheredtorequiresthemeasuringtotakeplaceunderoperatingconditions.Inschoolsparticularattentionshouldbepaidtotheventilationconditions.Theresultofanindoorairmeasurementdependslargelyontheframeworkandmeasuringcondi-tions.Itisthereforeessentialtoensurethattherelevantrecommendationsareobserved(FederalEnvironmentAgencypublication.BeurteilungvonInnenraumluftkontaminationenmittelsReferenz-undRichtwerten–eineHandreichung[Assessmentofindooraircontaminationusingreferenceandguidelinevalues–sometips].Bundesgesundhbl-Gesundheitsfosch-Gesundheitsschutz50:2007,pp.990–1005;VDIGuidelinesseries4300).Onlylaboratorieswithadocumentedqualityassurancesystemwhoparticipatesuccessfullyinexternalgroupexperimentsand/orcomparativelaboratoryresearchprogrammesshouldbegiventhemeasuringcontract..

IndoorguidelinevaluesforindividualVOCsarededucedbytheadhocworkinggroup,composedofmembersoftheIndoorAirHygieneCommis-sion(IRK)andtheWorkingGroupoftheSupremeHealthAuthoritiesoftheFederalStates(IRK/AOLGadhocworkinggroup),inaccordancewithaproceduralscheme.Itisrecommendedthatthesevaluesarealsoadheredtoinsideschools(seeTable5).

Guideline value II (RW II) is a proven value relating to impacts, which is based on current toxicological and epidemiological knowledge of the impact threshold of a substance when uncertainty factors are introduced. It represents the con-centration of a substance which, when reached or exceeded, requires immediate action, since this concentration is likely to pose a health hazard, especially to sensitive individuals spending long periods in the rooms.

A reading in excess of RW II should be combined immediately with a control measurement under normal conditions of use and – as far as possible and rea-sonable – with an assessment of the internal exposure of the users of the room.

Guideline value I (RW I) is the concentration of a substance in the indoor air at which, within the context of a study of an individual substance, on the basis of current knowledge, no damage to health is to be expected, even with lifelong exposure. A value exceeding this is linked with hygienically undesirable con-tamination outside the normal range. RW I can serve as a remediation target. It should not, however, be an “end in itself”; if possible a lower value should be achieved.

AvaluehigherthanGuidelinevalueIindicatesincreasedexposureunac-ceptablefromahygieneperspective.Fromarealisticpointofviewnostruc-turalorotheralterationsrelatingtothesourceshouldbecarriedoutinthefirstinstance,butaboveallventilationand,dependingontheindividualcase,cleaningshouldbesteppedup.


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Table 5: IRK/AOLG ad hoc working group guideline values for indoor air (as at 2008): as well as VOCs this contains SVOCs (cf. Section B4) and a guideline value for mercury-containing vapours

Compound RW II (mg/m3) RW I (mg/m3) Year set

Toluene 3 0.3 1996

Dichloromethane 2(24h) 0.2 1997

Carbon monoxide 60(1/2h) 6(1/2h) 1997

15(8h) 1.5(8h)

Pentachlorophenol 1μg/m3 0.1μg/m3 1997

Nitrogen dioxide 0.35(1/2h) – 1998

0.06(1week) –

Styrol 0.3 0.03 1998

Mercury (as metallic vapour)

0.35μg/m3 0.035μg/m3 1999

Tris(2-chloroethyl) phosphate

0.05 0.005 2002

Bicyclic terpenes (lead substance α-pinen)

2 0.2 2003

Naphthalene 0.02 0.002 2004

Non-aromatic hydrocarbon mixtures (C9-C14))

2 0.2 2005

Atanytimethecurrentlistincludingfurtherinformationisdefinitive.Thisisavailableonlineat:http://www.umweltbundesamt.de/gesundheit/innenraumhygiene/irk.htm#4

TheIRK/AOLGadhocworkinggrouphasalsodrawnuprecommendationsonlimitsofindoorairconcentrationsforTotalVolatileOrganicCompounds(TVOCs).TheTVOCvalueisnottoxicologicallybased,owingtothedifferentcompositionofthemixtureofsubstancesoccurringinindoorair,butrepre-sentsatotalhygieneevaluationforVOCs.

TheTVOCevaluationisdividedinto5levels(seeTable6);therecommenda-tionsmadeatthepreviouslevelalsoapply–asfarasisreasonable–atthenextlevelup.TheprerequisiteforusingtheTVOCschemeisthattoxicologi-callybasedguidelinevaluesofindividualsubstancesarenotexceededindoingso.Aseparateassessmentisafundamentalrequirementifsubstanceswithlowodourthresholdsareinvolved,asthesecancauseproblemseveninlowconcentrationsbecauseoftheirodouractivity,orifabnormallyhighconcentrationsofindividualsubstancesoccur.


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Level 1

TVOCvaluesbelow0.3mg/m3arehygienicallyinsignificant,providedthatindividualsubstanceguidelinevaluesarenotexceeded.Theyaredesig-nated“targetvalues”(hygienicprecautionrange)andtheaimshouldbetomeetorifpossiblegobelowtheminindoorspaceswithinanadequateperiodaftercompletinganew-buildorrenovationwork.

Level 2

TVOCvaluesbetween>0.3and1mg/m3canbeclassifiedasstillhygieni-callyinsignificant,providedthatindividualsubstanceguidelinevaluesarenotexceeded.Thisconcentrationrangeindicatesforexamplethatsolventemissionsarenotyetcompletelyexpelledandpointstotheneedformoreintensiveventilation.

Level 3

TVOCvaluesbetween>1and3mg/m3shouldbeassessedasabnormalandapplyforalimitedtime(<12months)asupperlimitsforspacesintendedforlengthyoccupation.Inresidential,schoolorofficespacesinnormaluse,whererenovationorrefurnishinghasnotrecentlytakenplace,aTVOCconcentrationof1mg/m3undernormalconditionsofuseshouldnotbeexceededinthelongterm,asthiswouldbejudgedtobeanindicationofanadditionalandpossiblyharmfulVOCemission.Thehealthimplicationsofunusualinstancesofreferencevaluesbeingexceededshouldbeexam-ined.Anindividualtoxicologicalassessment,atleastofthesubstanceswiththehighestconcentrations,isrecommended.Thefollow-upmeasurementtotesttheindoorairqualityiscarriedoutundernormalconditionsofuse.

Level 4

SpaceswithTVOCvaluesbetween>3and10mg/m3areassessedashygi-enicallysignificantandshouldonlybeusedtemporarily(foramaximumof1month),ifnoalternativeisavailable,andwiththeimplementationofmoreintensiveregularventilationprocedures.Anindividualtoxicologi-calsubstanceevaluationorsubstancegroupevaluationshouldbecarriedout.Thefollow-upmeasurementtotesttheindoorairqualityiscarriedoutundernormalconditionsofuse.


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Level 5

TVOCvaluesbetween>10and25mg/m3areclassifiedashygienicallyunac-ceptable.Useoftheroomshouldasarulebeavoided;atthemostonlyshortperiodsshouldreasonablybespentthere(lessthanonehourperday),andmoreintensiveregularventilationproceduresimplemented.Atvalues>25mg/m3theroomshouldnotgenerallybeused.Thefollow-upmeasure-menttotesttheindoorairqualityiscarriedoutundernormalconditionsofuse.

AswellastheguidelinevaluesandTVOCclassificationsreferencevalues,whicharedeterminedfromthestudyofalargenumberofindoorspaces,canalsobeusedinmakingapreliminaryassessmentofVOCconcentra-tions.ThelatestreferencevaluescanbefoundinapublicationfromtheFederalEnvironmentAgency(Bundesgesundheitsbl-Gesundheitsforsch-Gesundheitsschutz50:2007,pp.990–1005).Ameasuringlaboratoryshouldspecifythesourceofthereferencevaluesusedandmustonnoaccountlinkanyhealthstatementstotheexceedingofareferencevalue(alsooftencalledanorientationvalue).

Table 6: Hygienic evaluation of TVOC values and resulting recommendations for action (Federal Environment Agency 2007)

Level / Concentration range / Questions requiring clarification / Recommendations

1

Hygienicallyinsignificant.Noproblemsasarule.

Areguidelinevaluesbeingexceeded?

Nofurthermeasures.

2

Stillhygienicallyinsignificant,providedthatnovaluesareexceededforindividualsubstancesorsubstancegroups.

Isolatedcasesofhealthproblemsorodourperceptions,e.g.afterminorrenovationworkornewfurnishingsinrecentweeks.

Areguidelinevaluesbeingexceeded?Arevaluessignificantlyabovereferencevalues?


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Aretheindoorclimateconditions(airexchange,temperature,humidity)perfect?

Adequateairing,especiallyafterrenovationwork.

IdentifyVOCsources(e.g.inspectionofthespace).

Checkuseofcleaningandpolishingproducts.

Follow-upreadingstomonitorvaluesexceedingtheguidelinevalueundernormaluse(seeChapter9).

3

Hygienicallysignificant.

Useofroomsthatareoccupiedregularlyonlyacceptableforalimitedperiod(<12months).

Within6monthsTVOCconcentrationsshouldfallsignificantlybelowtheTVOCvaluerecordedatthestart.

Incidentsofhealthproblemsorodourperceptions,e.g.aftermajorrenovationwork.


Arevaluessignificantlyabovereferencevalues?


Checkvaluesexceedingtheguidelinevalueimmediatelybyfollow-upreadingsundernormaluseconditionsandbearinmindadviceinChapter4whenmakingtheevaluation.

Testvaluessignificantlyabovereferencevaluesforrelevancetohealth.

Inallcases:carryoutsearchforsourceandcheckventilationroutines:implementintensiveventilationandifnecessaryestablishconditionsforuseandventilation.

Controlreadingorfollow-upreadingrecommendedafterapprox.1month(undernormaluse).

Ifafter12months,despitetheeffortsdescribed,theTVOCconcentra-tionremainsabove1mg/m3,adequateremediationmeasuresshouldbeincorporatedinfurtherplanning.


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4

Hygienicallysignificant

Useofroomsthatareusedregularlyonlyacceptableforalimitedperiod(<1month).

TVOCconcentrationsshouldfallbelow3mg/m3within1month.

Incidentsofincreasingnumbersofhealthproblemsorodourpercep-tions,e.g.aftermajorrenovationwork.




Checkvaluesexceedingtheguidelinevalueimmediatelybyfollow-upreadingsundernormaluseconditionsandbearinmindadviceinChapter4whenmakingtheevaluation.

Testvaluessignificantlyabovereferencevaluesforrelevancetohealth.Toxicologicalevaluationofindividualsubstancesorsubstancegroupsrequired.

Inallcases:carryoutsearchforsourceandimplementintensiveven-tilation;ifnecessaryestablishconditionsforuseandventilation,andarrangeappropriateminimisationmeasures.Iftheroommustbeused,thentolerableonlywithatimelimitperdayforamaximumperiodtobestipulatedbythehealthagency(perday/numberofhours/limitedperiod).

Controlreadingorfollow-upreadingrecommendedafterapprox.1month(undernormaluse).

Ifafter1month,despitetheeffortsdescribed,theTVOCconcentrationremainsabove3mg/m3,adequateremediationmeasuresshouldbeincorporatedinfurtherplanning.

5

Hygienicallyunacceptable.

Avoidusingroomifpossible.Atmost,usepermittedforalimitednumbersofhoursoverarestrictedperiod.

Atvaluesabove25mg/m3theroomshouldnotbeused.

TVOCconcentrationsshouldfallbelow3mg/m3within3months.


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Healthproblemsandodourperceptionsusual,e.g.afterfaultyapplicationoraccidents.




Monitorvaluesexceedingtheguidelinevalueimmediatelybyfollow-upreadingsundernormaluseconditionsandbearinmindadviceinChapter4whenmakingtheevaluation.

Testvaluessignificantlyabovereferencevaluesforrelevancetohealth.Tox-icologicalevaluationofindividualsubstancesorsubstancegroupsrequired.

Inallcases:carryoutsearchforsourceandimplementintensiveventila-tion;establishconditionsforuseandventilation,andarrangeappropriateminimisationmeasures.Iftheroommustbeused,thentolerableonlywithatimelimitperdayforamaximumperiodtobestipulatedbythehealthagency(perday/numberofhours/limitedperiod).

Controlreadingorfollow-upreadingwithin1month(undernormaluse).

Ifbyimplementingminimisationmeasuresavaluebelow10mg/m3isachievedwithinthetimeframeunderconsideration,butaconcentrationof3mg/m3stillexceeded,therecommendationsinLevel4apply.Ifafter1month,despitetheeffortsdescribed,theTVOCconcentrationremainsabove10mg/m3,theroommustnotbeusedandadequateremediationmeasuresshouldbearranged.

B-3 Formaldehyde

Formaldehyde(chemicalname:methanal–CH2O)isoneofthebestknown

andbestresearchedairpollutantsinindoorspaces.Asaresultofitsdiverseindustrialusesinthemanufactureofsheetandinsulationmaterials,paints,cleaningagentsandcosmeticsthesubstancecanusuallybedetectedinin-doorair.Wood-basedmaterials(particleboard,coatedparticleboard,woodcoreplywood,veneers,fibreboard)andarticlesproducedfromwood-basedmaterialssuchasfurniture,doorsandpanellingarestillthemostimportantsourcesofformaldehydeinindoorareas.

Formaldehydeisanimportantconstituentofadhesivesinthesheetmate-rialindustry.Amongstthoseusedareureaformaldehydeadhesiveresins(UFglues),phenol-formaldehydeadhesiveresins(PFglues),melaminefor-


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maldehydeadhesiveresins(MFglues)andmelamine-urea-formaldehydead-hesiveresins(MUFglues).Aftercompositewoodmaterialsmanufacturedinthiswaywereusedforlargesurfacesandinstallationstherewereincreasedemissionsofformaldehydeintheindoorairinschoolbuildingsinthepast,andeventodaytherestillarestilloccasionalinstances.

Sincethebeginningofthe1980sformaldehydeemissionsfromwood-basedmaterialshavebeenregulatedinGermany.TheChemicalsProhibitionOrdi-nance(Chemikalien-Verbotsverordnung)stipulatesthatonlythosecompositewoodmaterialswhichareprovennottoexceedanaverageconcentrationof0.1ppmunderdefinedtestconditions(“emissionclassE1”)maybeputonthemarket.Exceptionstothisarewood-basedmaterialstobelaminated,forinstanceformakingfurniture,whichisstillpermittedtoemitsignificantlymoreformaldehydenowadays.Asanexample,E1wood-basedmaterialsforuseasflooringarenowstandard.Sheetmaterialproductsthatareparticular-lylowinformaldehyde(averageconcentrationinatestchamber<0.05ppmunderdefinedconditions)canbeidentifiedbytheBlueAngel.Theamountofformaldehydegivenofffromcompositewoodmaterialsisalsoinfluencedbytheclimaticconditionsintheroom.Thushigherindoorairtemperaturesandhigherrelativehumidityleadtoanincreaseinemissionsrates.

Somemanufacturershavestoppedaddingformaldehydetotheirwood-basedmaterialsandinsteadusepolyurethanegluesforadhesion.Althoughthediisocyanatesinthesearelikewisenottoxicologicallyinsignificantduringthemanufacturingprocess,theydohoweverremainboundupinthewood-basedmaterialsafterwardsandthereforedonotentertheindoorair.

Intermsofhealthimpactsthroughexposuretoformaldehydeinindoorenvi-ronmentsirritationofthemucousmembranesisthemostsignificant.Withlong-lastinghighformaldehydepollution,whichoccurredatsomeworkplac-esinpreviousdecades,theirritationcanleadtochronicinflammationofthenasalmucousmembrane,fromwhichcancercandevelop.In2004formalde-hydewasclassifiedas“carcinogenictohumans”bytheInternationalAgencyforResearchonCancer(IARC).

Formaldehydehasapungentodour.TheWHOestimatesthatsomepeopleperceivetheodourofformaldehydeevenat0.03mg/m3.Aslongagoas1977theGermanFederalMinistryofHealth(BGA)recommendedaguidelinevalueof0.1ppm(=0.12mg/m3)offormaldehydeinindoorair,regardlessoftheactualindoorairtemperaturesandhumidity.Inviewofthere-evalu-ationofthecarcinogeniceffectofformaldehydethisvaluewasre-examinedandconfirmedbytheFederalInstituteforRiskAssessment(BfR)in2006.TheIndoorAirHygieneCommission’sadhocworkinggroupendorsedthisproposal.Intheviewofthesecommitteestheriskofcancerbelow0.1ppmofformaldehydeisnegligible.


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B-4 Semi-volatile organic compounds (SVOCs)

Thegroupofsemi-volatileorganiccompounds(SVOCs)includessubstancesandsubstancegroupswhoseboilingrangeliesabovethatofVOCs(seedefinitioninSectionB-2).FormostSVOCsingestionfromfoodsofanimaloriginrepresentsthemainexposurepath.However,SVOCscanalsobeabsorbedviaindoorair.IntheindoorenvironmentthevastmajorityofSVOCspresentareboundtosuspendeddustparticlesortosurfacesintheroom.AmongthemostfamiliarSVOCspresentinsignificantquantitiesarethefireretardantsandsoftenersusedinplasticproducts.Theseandothercompounds,whoseappearanceinrecentdecadeshasbeenthesubjectofparticularlyintensivediscussions,includinginschools,namelypolychlorin-atedbiphenyls(PCBs),agentsinwoodpreservativesandpolycyclicaromatichydrocarbons(PAHs)willbedealtwithinmoredetailbelow.

Fire retardants

Fireretardantsaredesignedtomakeplastics,woodandcompositewoodmaterials,insulatingmaterialsandtextilesnon-flammable.Thefireretard-antsareintheformofanadditivemixedintotheproducttobeprotectedorareboundupreactivelyinthematerial.Thesubstancesappliedasadditivesinparticularcanbereleasedintotheenvironmentagainlater.Variousinorganicand/ororganicsubstancegroupsareusedasfireretard-ants,inEuropebeingmainlyaluminiumoxides,boronoxides,magnesiumoxidesandantimonyoxides,chlorinatedparaffins,variousbrominatedcompoundssuchaspolybrominateddiphenylethers,andhalogenatedandnon-halogenatedorganophosphateesters(OPEs).Fire-retardantagentsinplasticsoftenalsoperformthefunctionofasofteneratthesametime(e.g.polybrominateddiphenylethers).

Todatethereleaseoffireretardantsintotheindoorenvironmentundernormallivingconditionsorduringnormalusehasbeenpoorlyunderstood.Researchintotheoccurrenceofphosphoricacidestersinindoorairwasonlycarriedoutinthe1990s.Phosphoricacidestersweredetectedeveninreadingsfromhousedust.

Aswellastheirtoxicpropertiesthedurability(persistence)andabilitytoincreaseinthebody(bioaccumulation)offireretardantsalsoplayapart.Aparticularlynegativeexampleofthisisthepolychlorinatedbiphenyls,whichhoweverhavenotbeenusedasfire-retardantagentsforsometime(seefollowingsectiononPCBs).TheorganobrominatedcompoundsandOPEsarealsocriticalinthisrespect.TheIRK/AOLGadhocworkinggrouphasproposedasumguidelinevalueforindoorair(RWI)of0.005mg/m3


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fortris(2-chloroethyl)phosphate(TCEP),tris(2-chloroisopropyl)phosphate(TCPP),tri-n-butylphosphate(TBP),tris(2-butoxyethyl)phosphate(TBEP),tris(2-ethylhexyl)phosphate(TEHP)andtriphenylphosphate(TPP)(cf.guide-linevaluesinSectionB-2).

Softeners, phthalic acid esters

Phthalicacidesters(phthalates)areaddedtoplasticsassoftenersinlargequantities(mostlymorethan10%).Forthisreasontheyaresomeofthesubstanceswhicharefoundinrelativelyhighconcentrationsinmostenvi-ronmentalmediaandespeciallyinfoodaswell.Owingtotheirlowvolatil-itysoftenersarefoundinindoorenvironmentslessintheairthanindustdepositsandonsurfaces.Potentialemissionsourcesofphthalicacidestersinindoorareasarewallcoverings,wallpaints,floorcoveringsandelec-tronicequipment.Buildingmaterialsforwallsandfloorscanbearelevantsourceofphthalicacidestersbecauseoftheconsiderableproportionofsurfaceareainaroom.ThePVCusedbypreferenceinwallandfloorcover-ingscanforexamplehaveaphthalicacidestercontentofmorethan30%.Untiltheendofthe1990sthismainlyinvolveddi-n-butyl-phthalate(DBP),diisobutylphthalate(DiBP)anddi(2-ethylhexyl)phthalate(DEHP).Nowadaystheuseofdi-iso-nonylphthalate(DINP)ispreferred.Thediacidesterssuchasadipateswhicharealsousedassoftenershaveasyetseldombeendetectedinindoorenvironments.Phthalicacidestersaresuspectedofencouragingthephenomenonof“blackhomes”(thefoggingphenomenon).

Polychlorinated biphenyls

Polychlorinatedbiphenyls(PCBs)wereproducedindustriallyfrom1929tothebeginningofthe1980s.Theyareamixtureofvariouschlorinatedsinglecompounds(amaximumof209differentcompoundtypes[conge-ners]).Inthepasttheywerewidelyusedasinsulators,fireretardantsandsofteners.TheirsaleandusehasbeenprohibitedinGermanysince1989onaccountoftheirpersistence,theaccumulationintheenvironmentandespeciallyinthefoodchain,andtheirtoxicity.Sincethenconcentrationsintheenvironmentandalsointhefattytissueofthehumanbodyhavebeenfallingslowly.

AttentionwasfirstdrawntotheoccurrenceofPCBsinindoorenvironmentsinthemid-1980sbyPCBsleakingfromcondensersforfluorescenttubes.Inthemeantimethesehavebeenreplacedanddisposedof,assince1.1.2000condenserswithaPCBcontentofover50mg/kgmaynolongerbeused.PCBswerealsousedonalargescaleassoftenersinjointingcompounds(onapolysulphiderubberbase)andinflame-retardantorsound-absorbingcoatingsforacousticceilings(seesectiononfire-retardants).Withthese


56

“open”applicationsPCBcouldenterthesurroundingairdirectly.InthecourseoftimeevenstructuralcomponentsanditemsoffurnitureintheseroomsthatwerefreeofPCBscouldbecontaminatedbythem,andtheninturncontributetoindoorairpollution(so-calledsecondarysources,e.g.floorandwallcoverings).Inthemainthisaffectedschoolbuildingserectedinthe1960sand1970s.

Owingtothehighcostoftakingreadings,notallpossiblePCBcongenersinindoorairaremeasured.Insteadmeasurementsarerestrictedtothe“in-dicatorPCBs”.TheseincludePCBs28,52,101,138,153and180.AssomePCBcongenersalsoexhibitadioxin-likeeffect,theFederalEnvironmentAgency’sadhocguidelinesworkinggrouphasrecommendedincludingPCB118,astheleadsubstanceinthissubstancegroup,since2007(Bund-esgesundheitsbl-Gesundheitsforsch-Gesundheitsschutz50:2007,pp.1455-1465),especiallywhenitisascertainedbyinvestigationsormeasurementsthatmainlyhighlychlorinatedclophenshavebeenused(perhapsinceilingboardsorcoatings).

Twocasesshouldthereforebedistinguished:

a)IfjointsealantscontainingPCBswithachlorinationgradelowerthanClophenA60aredefinitelypresent,thetotalPCBs,basedon6in-dicatorPCBs(excludingPCB118),serveasanassessmentcriterion.Measurestoreduceexposureshouldbeexaminedforindoorairconcentrationsabove3μgpercubicmetrefortotalPCBs.Atlowercon-centrationsventilationroutinesshouldbeinvestigatedandimprovedifnecessary.

b)ForceilingboardsandcoatingscontainingClophenA50orClophenA60andPCBsourcesthatcannotbeidentifiedwithcertaintythetotalPCBcontentcanlikewisebeusedtomakeanevaluation.Uptoaconcentrationof1μgtotalPCBs/m3willcertainlybebelowaTEQ(toxicequivalentquantity)valueof5pg/m3.AthighertotalPCBcontents(>1μg/m3)theconcentrationofPCB118shouldbeusedforassessment.Forindoorairconcentrationsabove0.01μgPCB118/m3measurestoreduceexposureshouldbeinvestigated.Atconcentrationsbelowthisventilationroutinesshouldbeinvestigatedandimprovedifnecessary.

AtpresentthereareconsiderabledifferencesbetweentheLänderwithregardtothehealthevaluationofPCBsinindoorairandtotheextentofnecessaryremediationmeasures.InmanyoftheLändersubstantialpartsoftheGermanInstituteforConstructionEngineering’s“GuidelinesfortheassessmentandremediationofPCB-contaminatedbuildingmaterialsandcomponents(PCBGuidelines)”havebeenintroducedastheacknowl-


57

edgedtechnicalrulesforworks,whileinotherLändertheyonlyapplywithsubstantialamendments.InordertofacilitateaprocedureforthewholeofGermany,theadhocworkinggrouprecommendsinits2007statementthatthehealthevaluationofPCBsiscarriedoutdependentonthetypeofPCBsource(sealants,ceilingboards,etc.).

TherearealsodifferentregulationsintheLänderwithregardtohealthandsafety.Thehealthandsafetyrecommendationsapplicableineachcaseshouldbeobserved.

Asabasisfororderingfurtheractiontobetakenacontrolmeasurementunderdefinedventilationconditionsshouldbeundertaken:inindoorspac-eswithventilationregulationssuchasschoolsnormallong-termmeasuringforPCBsshouldbecarriedoutduringseveralcyclesofuse,whileadheringtotheprescribedventilationwiththeroomsinnormaluse,withventila-tionduringbreaktimestakingplaceasprescribed.Themeasuringbeginsafterthefirsttimethewindowsareclosedandendsbeforethelasttimethewindowsareopened(includingseveralcyclesofuse).Themeasure-mentsshouldpreferablybecarriedoutwhiletheroomisinuse.Ifpossible,measuringshouldtakeplacethroughoutatleastonecompleteschoolday,inordertoregistertheinfluenceoftemperatureinthecourseoftheday.

ThefundamentalaimofPCBremediationshouldbetoremovetheprimarysourcesandminimisethesecondarysourcesasfaraspossible.Duringreme-diationworktheARGEBAU(ConferenceoftheLänderMinistersandSena-torsresponsibleforurbandevelopment,constructionandhousing)guide-linesfortheevaluationandremediationofPCB-contaminatedconstructionmaterialsandcomponentsinbuildingsshouldalwaysbeobservedintheversionapplicabletotheappropriateLand(cf.PartE).

Pentachlorophenol

Untilwellintothe1970stimberandtimbercladdinginindoorenviron-mentswasoftentreatedwithwoodpreservativescontainingpentachlo-rphenol(PCP),withpolychlorinateddibenzodioxinsanddibenzofuransascontaminants.Becauseoftheirlonghalf-lifeintreatedwoodPCP,dioxinsandfuranscanstillbedetectedintheseindoorareastoday,althoughtheuseofPCPhasbeenprohibitedinGermanysince1989.SomeofthePCPreleasedfromthewoodistakenupbythedustintheroomandbyfurni-ture,curtainsorcarpets.PCPuseshouldalwaysbeassumedifvaluesabove0.1μg/m3ofindoorair,morethan5μgPCP/ginaccumulateddust(olddust)andmorethan1μg/gin“freshdust”(dustthathasnotlainforlongerthanoneweekbeforethesampleistaken)aredetected.


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Iftheindoorairconcentrationtobeexpectedinthemiddleoftheyearisabove1μg/m3,remediationisrequired.Afterremediationtheaimshouldbetoachievelong-termindoorairvaluesbelow0.1μgPCP/m3ofair.RegulationsondeterminingtheneedforremediationinPCP-contaminatedspacesandsuggestionsforsuitableremediationaresetoutintheARGEBAUguidelinesontheevaluationandremediationofconstructionmaterialsandcomponentsinbuildingscontaminatedwithpentachlorophenol(PCP)(“PCPguidelines”)–seePartE.

Ifchemicaltreatmentagainstinsectswasneededatallforwood,dichloflua-nidwasthefirstsubstituteforPCPavailable,followedbytebuconazole,propiconazoleandotheragents.

Lindane

Lindane(gamma-hexachlorocyclohexane;γ-HCH)wasusedasaninsecticideinagricultureandforestry,woodpreservationandveterinaryandhumanmedicinefromaround1945.Foralongwhilelindanewasparticularlyim-portantincontrollingwood-destroyinginsectsandinpestcontrolmeasuresaspartoftheGermanFederalCommunicableDiseasesControlAct(Bundes-seuchengesetz).

Atthattimelindanewasusuallypresentin“WestGerman”woodpreserva-tivesincombinationwithpentachlorophenolinaratioofaround1partlindaneto10partsPCP.InEastGermanyacombinationoftheagentsDDTandlindanewaspreferred.Sincelindanewasgenerallyusedasanagentinwoodpreservativestogetherwithpentachlorophenol,itisprimarilythePCPcontaminationthatisinevidenceinaffectedschoolrooms.Therefore,bycarryingoutPCPremediationinaccordancewiththePCPguidelines,lindanecontaminationwillgenerallybereducedatthesametime.

It isnotnecessary tousechemicalwoodpreservativeswithbiocidalagents inindoorenvironments.Inthecaseofpestinfestationalternativewoodtreatments(e.g.thermalconditioning)canbeusedifneeded.

Chemicalwoodpreservativesshouldnotbeusedinconstructioncomponentsandfittingsthatarevisibleandaccessibletotheroom.

Is the use of chemical wood preservatives still permitted nowadays?


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Chloronaphthalenes

Untilwellintothe1970schloronaphthaleneswereusedaswoodpreserva-tivesinthemanufactureofbondedwood-basedmaterials,especiallyparticleboards.Thesewereusedasflooringsheetsandtoasmallextentaswallandceilingliningsaswellasindemountablebuildingswherechildren’sdaynurseriesandpre-schoolplaygroupswerehoused.Themixturesconsistedpredominantlyofmono-anddichloronaphthalenes.Chloronaphthalenescouldberecognisedbytheirtypicalmustysmell(cf.SectionD-2.2).

AguidelinevalueI(RWI)of20μg/m3andaguidancevaIueIIof200μg/m3fortheevaluationofchloronaphthaleneswereproposedbytheFederalMin-istryofHealthofthetime.Whenmakingahygieneevaluationofindoorenvironmentscontaminatedwithchloronaphthalenestheunpleasantodouremittedbythesubstancemustalsobeconsidered.Odourthresholdvaluesintherange4–10μg/m3arespecifiedforthemonochloronaphthalenes.

Polycyclic aromatic hydrocarbons

Polycyclicaromatichydrocarbons(PAHs)arisefromtheincompletecombus-tionoffossilfuelsorotherorganicmaterials.Morethan200ofthesecom-poundsexhibitingthreeormorebenzeneringsaretobefoundinoutsideair,especiallyinconurbations.InindoorenvironmentsPAHscanentertheairfrom,forexample,tobaccosmoke,leakingfluesfromcoalstovesandfromusingpoorlyfunctioningfireplaces.

TarandtarproductsalsocontainPAHs.Untilthe1950sand1960star-basedadhesives(ormixturesoftarandbitumen)weresometimesusedinlayingwoodfloorsandoccasionallyalsoinlayinglinoleumfloorcoverings,mainlyinhousesandflats.However,onlyafewcaseswhereadhesivesofthiskindwereusedinschoolshavesofarcometolight.Inindoorenvironmentswheretar-basedadhesivematerialshavebeenused,anincreasedPAHcon-tentinthegluecanalsocausehousedusttobecontaminatedbyPAHs.

ManyPAHsareclassifiedascarcinogenic,includingbenzo(a)pyrene(BaP),theleadsubstanceinthePAHs.In1998acommissionofexpertsattheFed-eralEnvironmentAgencyissuedrecommendedvaluesforbenzo(a)pyrene(BaP)asthePAHleadsubstanceforadhesivesandhousedustcontent.Thesewerealsoadoptedbytheconstructionauthority(ARGEBAU).Inaccordancewiththese,measurementsofhousedustconcentrationsaretobecarriedoutwhenconcentrationsinadhesivesexceed10mg/kgBaP,takingintoconsid-erationtheconditionoftheparquet.IftheBaPcontentexceeds100mg/kgofdust(dustdepositsnomorethanaweekoldatthetimeofsampling)measurestoreduceexposureshouldbeundertakeninschools(GermanInstituteforConstructionEngineering,“AdviceonPAHs”,June2000).


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B-5 Dust

Dustisthecollectivetermforsolidparticlesthatremaindistributedthroughtheairoverafairlylongperiod(suspended)orsettleonthefloorandonsurfaceswithinashorttime(sedimentary).Dustparticlescanvaryconsiderablyinsize.Particlessmallerthan100nmaretermedultra-fineparticulatematter,particlesupto2.5μmparticulatematterandparticleslargerthan2.5μmascoarserparticulatematter.Allparticlesuptoadiam-eterofaround30μmaresuspendeddust(TSPs–TotalSuspendedParticu-lates).Dependingonthesizeanddensityofthedustparticlestheseremainsuspendedforacertaintime.Particlesof10μmandmoreareoftendepos-itedwithinafewminutes.Finerparticlesof,forexample,1μm,canremainsuspendedforseveraldays.Veryfineparticlesof,forexample,10nm,reactwitheachotherintheairandformlargerparticles,oraretakenupbylargerparticles.

Thesmallerparticlesare,thefurthertheycanpenetrateintotherespiratorytracts.Particlesmorethan10μminsizewillbarelygetbeyondthelarynx,andonlyasmallminorityofthemcanreachthebronchialtubesandthepulmonaryalveoli.Ultra-fineparticlescanenterthebloodstreamviathepulmonaryalveoliandspreadthroughthebodyviatheblood.

Itisnotonlythesizeoftheparticleswhichiscrucialforthehealthim-pactofdusts,butalsotheirchemicalandbiologicalcompositionandtheirmorphologicalstructureandform.Aswithparticlesize,thecomposition,structureandformarecharacterisedbythetypeofsourcefromwhichtheyemanate.

Withregardtotheclassificationofdustsadistinctionshouldbemadebe-tweenparticulatesinoutsideandindoorair.Itcanbeassumedthatoutsidetheconcentrationofparticlesintheairisveryquicklydiluted.Theparticleconcentrationsandcompositionsareoftensimilar,exceptduringspecialweathersituationsandinspeciallocalconditions.

Thesituationinindoorenvironmentsisquitedifferent;herethedistribu-tionareasareconsiderablysmaller.Dilutioneffectsarenotasusefulasintheairoutsideandinthiscaseareparticularlydependentonventilationmethodsandaircirculationinthebuilding.Furthermore,inindoorareasitmustbetakenintoaccountthatparticleswillreactmorevigorouslywitheachotherorwillbegivenoffbywallsurfaces.Electrostaticprocessesintheairalsoinfluencethedistributionandemissionofparticles.Thesourcesintheindoorenvironmentvaryandaredependentonindividualuse.Sedimentaryparticlescanbereturnedtemporarilytothesuspendedstatethroughmechanicaldisturbance.Asthishappensthestructureandproper-


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tiesoftheparticlescanalter.Theprocessesmentionedarelargelydepend-entontheexistingstructuralconditionsatthesite.Thisallleadstoawidevariationinthelevelofpollutionanditscompositionintheindoorenvi-ronment,andtoitbeingheavilycharacterisedbytheprevailingindividualcircumstances.

Avarietyofsourcesofparticulatematteroccurinsideschools.Herewearemainlyconcernedwithcoarserparticulatematter.Sourcesofthisare:

Outsideair

Dustbroughtinonshoesandclothes

Particlesreleasedfromskinandhair

Particlesreleasedduringcookingandbakinginhomeeconomicspracticalareas(somecoarserparticles)

Workintechnologylessons,especiallysandingandsawing.

Inadditionsmallerparticlesalsooccur.Sourcesoftheseare:

Outsideair

UseofBunsenburners,andburningcandles

Smokeproductionfromchemistryandphysicsexperiments

Particlesreleasedduringcookingandbakinginhomeeconomicspracticalareas(somesmallerparticles)

Copiersandlaserprinters.Inthiscaseultra-fineparticlesplayapar-ticularlyimportantpart,asthemostrecentresearch,includingattheFederalEnvironmentAgency,shows.(Theresultsofthestudyareavail-ableat:http://www.umweltdaten.de/publikationen/fpdf-l/3016.pdf)

Outsideairconcentrationsofsuspendedparticulatematteralsohaveaconsiderableinfluenceontheconcentrationsoffinerparticlesinschools,whilethecoarserparticulatematterelementmostlycomesfromindoorsources(seeabove).Inareasoftheschoolusedregularlytheparticulatematterconcentrationinsidecanbemarkedlyhigherthanintheoutsideair.Thisappliesespeciallytothecoarserelementoftheparticulatematter.Thedustconcentrationinsideschoolsdependsamongstotherthingsonthefrequencyofuse(numberofpupils,howoftentheroomisused),thesizeoftheroomandthetypeofuse(classroomsfortheoreticalsubjects,laborato-riesforphysics,biologyandchemistryexperiments,craftrooms,etc.).

Intechnologylessonsdustiscreatedbysandingandsawing.InchemistryandphysicslaboratoriesdustiscreatedbyexperimentsproducingsmokeandbyusingBunsenburners(cf.SectionA6).Incidentsofdustpollution


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duringscienceexperimentsandcraftworkcanbeminimisedbyintensiveventilation,usingextractorsduringparticularsandingproceduresand–ifnecessary–wearingasimpleprotectivefacemask(e.g.fromtheDIYstore).

Besideschemicalsubstances,biologicalsubstances,suchasmicro-organ-isms,bacteriaandtheirmetabolicproductsandcellcomponents,pollenanditscomponents,aswellasallergensgivenoffbyanimals,arealsoboundtodustinschools.

Inthecaseofbiologicaldusts(cf.SectionB-7),weareconcernedpredomi-nantlywithcoarserdusts,whichcanproducesomeveryspecificimpacts,especiallyinpeoplewithcorrespondingpredispositions(e.g.thosewithallergies).Cellcomponentswhichcantriggerallergenicortoxiceffectscanalsomakeupanelementoffineorultra-fineparticulatematter.

Duringcombustionprocessesmainlyfineparticulatematterandalsosomeultra-fineparticulatematteraregivenoffintotheindoorair.Toasmallextentfineandultra-fineparticlesarealsoreleasedwhilelaserprintersandcopiersareinuse(cf.SectionA-7).However,thesedimentaryparticlesstirredupagainbymechanicalactivities,e.g.duringlessonsintheclass-room,arepredominantlycoarserparticles,whennotonlydustlyingonthefloororthedesksisraisedagain,butalsothatwhichisfoundontheskin,hair,clothes,etc.Itshouldalsoberememberedthatsomeofthisdustisbroughtinfromoutside,onshoes,forexample.

Ahealthevaluationofsuspendedparticulatematterinindoorenviron-mentsisdifficult,aspopulation-relatedstudiesoftheimpactofparticulatematterrelytoalargeextentondataonparticulatematterpollutionoftheoutsideair.Convincinglinkswerefoundbetweenthesuspendedparticulatematterconcentrationintheoutsideairandeffectsonhealth–eventhoughthepeoplewherethestudieswerecarriedoutspentthebulkoftheirtimeindoors.Fromthatcanbeconcludedthatevenindoorstheparticulatematterfromtheoutsideairmakesasignificantcontributiontotheeffectsobserved.Itisnotyetclearwhatfurthercontributionismadebyindoorsources.

IntheirlateststatementtheIRK/AOLGadhocworkinggroupalsocomestotheconclusionthatthehealthimplicationsofdustsinindoorenvironmentsaredifficulttoevaluateatpresent(IRK/AOLGadhocworkinggroup,2008:GesundheitlicheBedeutungvonFeinstaubinderInnenraumluft[Signifi-cancetohealthofsuspendedparticulatematterinindoorair],Bundesge-sundhbl-Gesundheitsforsch-Gesundheitsschutz,inpress).Theassessmentcriteria(limitvalues)usedtoassessparticlesinoutsideairarenotapplica-bletoschools,onaccountofthedifferentsourcesituationandcompositionofparticulatematter.


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Lateststudieshavethereforedetectedmainlycoarserparticulatematterparticlesinclassrooms.However,accordingtocurrentknowledgeitisinfactthesmallerparticles(especiallyPM2.5andevensmallerparticles)thatareparticularlyimportantfromahealthperspective.Biologicalparticlesrepresentonepossibleexceptiontothis.

Despitetheuncertaintiessurroundingthehealthevaluationofparticulatematterintheindoorenvironmentitseemsadvisable,bearinginmindthepossiblerelationship,tominimisethedustconcentrationinthesespaces.VariousstudiesinGermanyhaveshownthatareductionindustpollutioninschoolscanonlybeexpectedwithregularintensiveventilationandstrictadherencetocleaningrecommendations(cf.Appendix1).

B-6 Fibre dusts

Thetermfibredustsdenotesparticleswithafibrousorneedle-likestructure.Importantfromahygieneperspectivearefibreslongerthan5μm,withadi-ameterlessthan3μm,whichexceedalengthtodiameterratioof3:1.Thesefibresareknownascriticalfibres.Theycanpenetratethelungtissueduringinhalation.

Therearenaturalfibresandsyntheticallyproducedfibres.Thesetwocatego-riescanbefurthersubdividedintoinorganicandorganicfibres.

Amongthenaturalinorganicfibresareasbestos,talcumandgypsum,whilethenaturalorganicfibresincludesheep’swool,animalhairandcellulosefi-bres.Importantsyntheticallyproducedinorganicfibres–alsocalledsynthet-icmineralfibres(SMFs)–areglass(amorphous)fibressuchasmineralwool(glasswool,rockwool,slagwool),ceramicfibres,continuousglassfilamentsandcrystallinefibres/single-crystalfibres.Inadditiontherearesyntheticorganicfibres(fibresproducedfromnaturalorsyntheticpolymers).

Effectiveventilationiskeytoreducingconcentrationsofparticulatematter,espe-ciallycoarserparticulatematter,inindoorairinschools.Aslongasthereisnosmoking,theparticulatematterconcentrationinindoorspacesdependsmainlyonthequalityoftheairoutside.

Measures to reduce the entry of particulate matter from the outside air, suchasinstallingmechanicalventilationsystemswithfiltersforincomingair,shouldonlybeconsideredinsituationswithextremelypollutedoutsideair.Thesesystemsshouldbeservicedregularly(changingfilters,checkingthatventilationshaftsarecleananddonotleak).

How can particulate matter pollution in schools be reduced as quickly as possible?


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Asbestos

Buildingproductscontainingasbestoswerestillusedinschoolbuildingsintothe1980s,andadistinctionismadebetweenmaterialsmadeofasbes-toscement(withanasbestoscontentofapprox.15%byweight)andlooselyboundasbestosproducts(e.g.asbestosspray,withanasbestoscontentofmorethan60%byweight).Asbestoscementproductswereusedasroofandfaçadepanels,windowsillsorwindowboxes,drainpipesandforparti-tionwalls(lightweightwalls).Asbestosspraywaspreferredinair-condition-ingandshaftsystemsforfiresafetyreasons.

Asaresultofageingprocessesandyearsofusethesebuildingshavegradu-allybeguntoreleasefibres.Especiallywhereventilationshaftsystemshadbeenspray-coatedwithasbestos,fibresreleasedbythiscouldenteradjoin-ingroomsdirectlywiththeairflow.

Do asbestos and SMF fibres have the same importance for health?

Thestructureis importantforthereleaseoffibresofthecriticalsize.Asbestosfibresarecrystalline fibres,whereasSMFsaregenerallyamorphous.The latterexhibitasignificantly lowertendencyto formdust.Unlikeasbestos theybreakacross thegrainandhavea lowerbiopersistence.Theyarealsoboundbysyn-theticresinandotheradditives.Thesefactorsrestrictthereleaseoffibredust.

Is asbestos still a problem in schools today?

Buildingmaterialscontainingasbestosarenolongerusedinschools.Ingeneraltheasbestosfibresintheasbestoscementproductsinstalledinthepastarefirmlyboundinthebuildingproduct.However,ifanyworkisdoneontheseproducts(e.g. drilling, sanding or cutting), large numbers of asbestos fibres can be re-leased.Forthisreasonworkofthiskindisnotpermitted.Inthecaseofasbestosspray,whichwasfrequentlyusedinair-conditioningshafts,forsealingcavities,etc.,thefibresarelessfirmlyboundthaninasbestoscementproducts,sothatthereleaseoffibresasaresultofageingistobeexpected.


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Asbestosisclassedasaknowncarcinogenicforhumans.Theinhalationofasbestosparticulatemattercancausethreemaindiseases:

1. Asbestosis:hardeningofpartsofthelungtissue.

2. Lungcancer,oftenincombinationwithasbestosis,latencyperiod(timeuntilthediseaseemerges)20–30years.Smokersareespeciallyaffected.

3. Pleural/peritonealcancer(mesothelioma),latencyperiod30–40years.

Theseasbestos-relateddiseasesoccurredespeciallyamongemployeesintheasbestosindustry,inwhoseworkplacesupto100millionasbestosfibresm3ofairweremeasured.

Theevaluationofanddecisiononremediationforlooselyboundasbestosproductsinbuildingsmustnotbemadeonthebasisofairmeasurements,butusingtheasbestosguidelinesintroducedintobuildingregulationsin1996,inwhichtheneedforremediationandtheurgencyforitareestab-lishedaccordingtoapointssystem.Fibremeasurementsfromtheairareonlyrequiredtocheckthesuccessofthemeasurestaken.

Synthetic mineral fibres (SMFs)

Syntheticmineralfibresarefrequentlyfoundinschools.Incontrasttoasbes-tosfibresthesedonotoccurnaturally,butareproducedindustriallyfromvariousinorganicsourcematerials(glass,rockssuchasbasalt,oxideceram-ics).Theyareusedmainlyforthermalandsoundinsulation.ThusSMFshaveacompletelydifferentrangeofusesfrompreviousasbestosproducts.

SMFsareusedtomakemineralwool(e.g.glasswool,rockwool)forfelts,matsorboardsaswellasforloosewool.Syntheticmineralfibreproductsdisplayexcellentheatresistanceandgoodinsulatingproperties,andarerelativelyeasytoworkwith.Aswithallmineralfibreproducts,thosemadeofmineralwoolgiveofffibredusts,onaccountoftheparticularpropertiesofthemate-rial(seenotesinbox),althoughfarlessthanasbestosproducts,forexample,whichinanycasewereemployedinareasotherthanheatinsulation,asdescribedabove.

Sincethe1980s,andstillmoresincethe1995ThermalInsulationOrdinance[Wärmeschutzverordnung]andtheBuildingEnergyConservationOrdinanceof2002,severalmillioncubicmetresofmineralwoolproductshavebeenusedinbuildings.

MineralfibresbuiltintosuspendedceilingconstructionsforsoundinsulationpurposesorintheformofacousticceilingboardshaveprovokeddiscussionaboutthepossiblereleaseoffibresfromSMFproductsintoindoorair,since,toprovideeffectivenoisecontrol,theceilingconstructionsmustbeperfo-ratedontheroomside,withthemineralwooljustlyinglooselyontop.


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Extensivemeasurementscarriedoutinavarietyofbuildingsatthebegin-ningofthe1990sshowedthatingeneral,wheremineralfibreinsulationhadbeenusedasdirected,noconcentrationsofSMFsexceedingthenormalbackgroundconcentrationsintheairoutsidewererecorded.

Inthenormalusephaseofbuildings,theconcentrationsthereinofSMFfibresofcriticalsize,whichcanbeclearlyassociatedwiththeproductused,are:

usuallynot raisedbyfibreemissions,ifheatinsulationhasbeencarriedoutproperly(insulationontheoutsidewall;double-skinwallwithinsu-latinglayerbetween;installationinsidetheroomorintheroofspacebehinddensepanelling,e.g.plasterboard,woodpanelswithvapourbarrierbehind(polyethylenefilm)and/orcomparableconstructions);

usually moderately raisedbyfibreemissions,ifthemineralwoolproductsareinstalledinsuchawaythatairisexchangedbetweenthemandtheindoorenvironment.Thisismainlythecasewithsuspendedceil-ingswithoutaproperlyfunctioningfilterlayer;

inisolatedcasessignificantly raisedbyfibreemissions(uptoseveralthousandfibresperm3ofair).Thisisconstantwheretherearecon-structionalfailingsorstructures,whichdonotconformtothelatesttechnicalstandards,ortemporaryifstructuralworkisbeingcarriedoutonbuildingcomponentscontainingmineralwool.

Since1998,inaccordancewiththeHazardousSubstancesOrdinance,syn-theticmineralfibreshavebeenclassifiedbytheirsubstancecompositionusingtheKI-Index(carcinogenicityindex)1:

KIvalue<30:K2–substancesthatshouldberegardedascarcinogenicinhumans.

KIvalue>30to<40:K3–substancesgivingcauseforconcernbecauseofpossiblecarcinogeniceffect.

KIvalue>40:nocarcinogenicityclassification.

FibreswithaKI>40areconsideredfreeofsuspicionofcausingcanceronthebasisofcurrentknowledge,astheyhaveabiopersistenceofonlyapprox.30–40days.AccordingtotheChemicalsProhibitionOrdinancethebiosolubilitycanalternativelybeestablishedthroughothermethodssetoutinitandtheproductstestedinthiswaydeclaredfreeofsuspicionofcaus-ingcancer.Thereforethe“KIcriterion”isseldomusednowasevidenceofbiosolubility.

1 The KI value is derived from the difference in the mass contents of the oxides of the elements Na, K, B, Mg, Ca., Ba and

twice the Al oxide content


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Sinceabouttheendofthe1990sonlyappropriatelytestedbiosolubleSMFinsulationmaterialshavebeenavailableonthemarket.Thereisnorisktohealthfromthesematerials.InthecaseofSMFproductsinstalledearlier(un-tilabout1998)necessaryrenovationmeasures,inthecourseofwhichfibrescanbereleased,shouldbeundertakenwithcautionandwithgoodventila-tionduringtheworks.TRGS(technicalrulesforhazardoussubstances)no.521describestheprotectivemeasuresthatmustbetakenduringdemolition,renovationandmaintenanceworkwitholdmineralwool.

SMFscanthereforebeclassifiedasfarlesshazardousthanasbestosfibres.TodatetherearenostudieswhichindicateaclearlinkbetweencancerinhumansandanincidenceofSMFpollution.Thefollowingreasonsmaybesignificant:

Mineralwoolinsulationproduceslessfibredustthancomparableas-bestosmaterials.Thisisevidentbothintheworkplaceandininvestiga-tionsintheindoorenvironment.Afibre-relatedcancerriskcouldnotbeproveninthemineralwoolinsulationindustry,whereasitisconsideredprovenintheformerasbestosindustry.

Thelengthwisesplittingoffibresobservedinasbestos,whichincreasesitsdanger,isnotaconcernwithsyntheticmineralfibres.

Theso-calledbiopersistence(i.e.thetimeittakesforafibretobreakdowninthebody)ofSMFshasbeenshortenedstillfurtherinrecentyearsthroughsuitablematerialcomposition.

SMFscanhaveanirritanteffect.ThusSMFsreleasedfromacousticceilingconstructionscanleadtoirritationsoftheeyesandtheupperrespiratorytractsinpeoplespendingalongtimeinthecontaminatedroom.Thiscanbelargelyavoidedwithacousticceilingconstructionsbyinstallingafilterlayer.

Mineralwoolproductsshouldnotbecomparedwithasbestos–eitherintermsofareasofuseorofsignificancetohealth (seeboxpage --).Forprecautionaryreasons,whenusingmineralwoolproductsinindoorspacescareshouldbetakentoensurethatfibresdonotcomeintoopencontactwiththeairinsidetheroom(e.g.inthecaseofacousticceilingsbyinstallingafilterlayer).Thereisnoreasononhealthgroundstoremovecorrectlyinstalledmineralwoolinsulation.Innew-buildstheuseofmineralwoolproductswiththeenvironmentlogoortheRAL[GermanInstituteforQualityAssuranceandCertification]“Mineralwool”markisrecommended.

Are synthetic mineral fibres as dangerous as asbestos?


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B-7 Biological substances

Aswellasthechemicalandphysicalairpollutantsdescribedintheprevioussections,substancesofbiologicaloriginalsoalwaysoccurinsideschools.Thisisbasicallyunavoidable,asmostofthesesubstancesareeitherbroughtinbythoseusingtheroomorentertheroomwiththeoutsideairduringventilation.

Pollutionfrombiologicalsubstancesinschoolbuildingsdifferssignificantlyfromlivingspacesonsomepoints,whileonothersthereisnosubstantialdistinction.

Thus,incontrasttohomes,noteworthyinfestationswithhousedustmitesareonlyseldomtobeexpectedinschools(incosycorners,forexample).Biologicalwastebinswithkitchenandgardenwastearerarelyfoundinsideschoolsasarule.However,foodremainsleftlyingaroundarenotinfre-quentlythecauseofmicrobialcontaminations.

Animal allergensontheotherhandplayapartinbothprivatehouseswheretherearepetsandinschoolbuildings,astheyarebroughtfromhomebythepupilsandteachers.Studiesinschoolshaveshownthatrelevantcon-centrationsofpetallergenscanoccurthere,especiallyfromcatsanddogs.Thesecanbefarhigherthantheconcentrationsdetectableinhomeswherepetsarekept.Theallergensarebroughtinontheclothesofpeoplewholiveinhouseswithpetsorhaveregularcontactwith;them.

Theallergenscanbefoundonallsurfaces,suchastables,chairs,etc.orinhousedust,whichaccumulatesespeciallyreadilyincarpeting.Hardfloorcoverings,whichcanbewashedandthereforecollectlittledust,arethere-foremucheasiertokeepfreeofallergensthancarpets.However,dustismoreeasilyraisedfromhardfloorsiftheyarenotcleanedregularly,whichiswhythetypeofflooringandfrequencyofcleaningmustnotbeconsid-eredinisolationfromeachother.

Insomeclassroomsitisalsousualtokeepplantsoranimalsincages.Thiscancauseallergicreactionsinafewpeople.Ifcagedanimalsarekept,thereistheadditionalproblemthatthestrawandanimalfoodalsocontainmicro-organisms,whichcanbereleased.Likewisethesoilinplantpotscanbeasourceofmould(seebelow).

Afurtherproblemwhichcanaffectallbuildings,regardlessofthetypeofuse,isdamp-relatedmould damage.Ifasufficientlyhighlevelofdampispresentoverafairlylongperiod,mouldandothermicro-organisms(bacteria,yeasts,protozoa)willgrowinsideoronmostbuildingmaterials.Althoughattacksofmouldpresentaprobleminmanyschools,theywillnotbeexaminedindetailintheseGuidelines,astherearealreadytwosetsof


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guidelinesfromtheFederalEnvironmentAgencywhichaddressthisissue(FederalEnvironmentAgency2002and2005,seereferenceinChapterIII).Theprinciplescitedintheseguidelinesonthedetection,evaluationandremediationofsourcesofmouldinindoorareasarealsovalidforschoolbuildings.

Thecausesofexcessivemoistureandconsequentlyofmouldgrowthinschoolscanvaryconsiderably.Owingtopoorconstructiondampfromout-sidecanpenetrateintothebuilding,e.g.moisturefromtheground,ifcellarwallshavenotbeenmadesuitablywatertight,rainwaterifroofsleakandheavyrainiffacadesaredamaged.Watercanescapeinsidethebuilding,e.g.ifpipesorhosesbegintoleak.Withexcessivehumidityinthebuild-ingand/orstructuralcomponentsattoolowatemperature,condensationcanformonthesurfacesoffittings.Inthislastcaseitisoftennoteasytoestablishthecause,becausewhetheracomponentistoocoldasaresultofstructuralfailingsorbecauseofinadequateheating,whetherhighhumidityhasarisenthroughinsufficientventilation,orperhapsasaresultofasyetunidentifiedmoisturedamagetothebuilding,canmostlyonlybeestab-lishedbymeansofreadings,whichmustbetakenandinterpretedbyex-perts.TheFederalEnvironmentAgency’sguidelinesonmouldremediation(“Schimmelpilz-Sanierungsleitfaden”,UBA2005)containdirectionsforthesystematicinvestigationofthecausesofattacksandfortheirremediation.

Inadditiontomouldbacteriafromavarietyofsourcesalsooccurinindoorenvironments.Onesourceofbacteriaistheusersoftheroom.Allhumansarecolonisedonthesurfaceoftheskinandintherespiratorytractbyvari-ousphysiologicallyoccurringbacteria(e.g.coagulasenegativestaphylocci,micrococci,andcorynebacteria).Thesearealsoemittedintotheairasaresultofmovementorbyspeakingandcoughing,whichiswhybacteriaarealwaysdetectableintheairofroomsthatareinuse.Thisaircontaminationisunavoidableandunproblematic,exceptintherarecaseswhensomeonecolonisedbyorillfrompathogenicmicro-organisms(e.g.tuberculosisbac-teria)isintheroom.However,asairisanunfavourablehabitatformanyoftheseorganisms,theymostlyonlysurviveforashorttime.

Bacteriacan,however,alsogrowwherethereismoisturedamageindoors,butmostbacteriarequirehighermoisturelevelstogrowthanmould.Actinomycetesareoftendetectedwherethereismoisturedamage.Likemouldthesebacteriaformmyceliaandsporesandwerethereforeprevi-ouslyknownasrayfungi(actino=ray,mycetes=fungi).Someactinomyc-etescanproduceapowerfulodour(musty,earthy,mouldy).Thespectrumofvarietiesofactinomycetesoccurringwithmoisturedamageandtheirsignificanceforhealthisthesubjectofongoingresearchatpresent.Withremediationmeasurestocuredampandmouldattacksthegrowthofbacte-riacanalsobeprevented.


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Humidifiers,indoorwaterfountainsandold,poorlymaintainedair-condi-tioningsystemswithintegratedrotatingsprayhumidifierscanbeanothersourceofbacteria.Certainbacteria,e.g.typesofthepseudomonasspecies,canmultiplyveryeasilyinthepartscarryingwater.However,inschoolstheuseofsuchequipmentisgenerallysuperfluous,asthehumidityinclassroomsnormallyinintensiveuseishighenough,owingtothemoisturegivenoffbytheoccupants.

Aquitedifferentproblemcanariseinconnectionwithshowersinsportsfacili-tiesandchangingrooms.Insomecircumstanceslegionella,whichcanmulti-plyespeciallyeasilyinatemperaturerangeof25–45oC,canoccurinthehotwaterinstallation.Legionellaisthereforemainlyaprobleminlargerbuildingswithlongrunsandperiodiclengthystagnationofthewaterinthemainssys-tem.Topreventthegrowthoflegionellathecoldwatershouldalwaysbecold(<20oC)andthehotwaterhot(60oCandatleast55oCwhenitreachesthetap).Areductioninhotwaterinlettemperaturetobelow55oC(e.g.tosaveenergy)shouldbeavoided.Theonlyremedyforanincidenceoflegionellaisathoroughanalysisofthesystemwithregardtothefactorsencouragingitandifnecessaryariseinhotwatertemperaturetoatleast55oCwhenitreachesthetap,aswellaspossiblestructuralalterationstothemainswaterpipeslead-ingtothem,sothatdeadspacesorstagnationzonesarelargelyavoided.Innewinstallations,aswellasthegeneraltechnicalstandards,theregulationsintheDVGW(GermanTechnicalAssociationforGasandWater)factsheetW551forpreventinggrowthoflegionellashouldbeobserved(seealsoPartA-4).

Outbreaksofheadliceinchildrenarearecurrentprobleminschools.Control-lingoutbreaksofheadlicerequiresclosecooperationbetweenparents,schoolandhealthagency.Everycaseoflicemustbereportedbynameinwriting(byletter,faxore-mail)tothehealthagency,inaccordancewithArticle34oftheProtectionagainstInfectionsAct(IfSG).Apreciseplanofactionshouldbeputinplacefortheprocedureintheeventoftheoccurrenceoflice(seetheschoolsspecimenhygieneplaninAppendixIfordetails).

Thehealthassessmentofsubstancesofbiologicaloriginisverycomplexandmustthereforebeconsideredinaslightlydifferentway.Sensitivitiesandaller-gies,irritanteffects,infections,intoxications,unpleasantodoursanddiscom-fortmustberegardedaspossibleeffects.

Substanceswithanexclusivelyallergeniceffectonlyinducesymptomsinaller-gicpeoplewithasensitivitytothecorrespondingallergen.Withinschoolsthisappliesmainlytoallergensoriginatinginanimals.Wherethesearesuspectedtheallergologististhebestpersontogivefurtherhelp,asitisusuallynoprob-lemtodiagnoseanallergytoanimalhair,cockroachesorhousedustmitesbymeansofmedicaltests.


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Itisnotalwayseasytotakecountermeasureswhentypicalsymptomsoccuratschoolinindividualpupilsorevenstaffwithacorrespondingallergy.Contaminationcanbereducedthroughregularthoroughcleaningandbyusingcertainfurnishingmaterials,suchashardfloorsinsteadofcarpets.Itisnotpossibletopreventpupilsandteachersfrom“bringing”therelevantallergensfromhome.

Assessingthehealthrisksofmoulddamageissignificantlymorecom-plicated.Itisknownfromscientific,epidemiologicalstudiesthathealthproblemscangohand-in-handwithmoisturedamageandmouldgrowthintheindoorenvironment.Forthisreasonmouldgrowthindoorsshouldberegardedasahygieneproblemandshouldnotbetolerated.Neverthe-less,thediscoveryofasourceofmouldinsidethebuildingshouldnotbeequatedwithanacutehealthrisktoitsusers.

Thefundamentalassumptionisthatmanytypesofmouldcancauseal-lergicsymptomsiftheyhaveasuitablyintensiveorlong-terminfluence.Onthebasisofcurrentknowledgeintoxicationscanbepracticallydisre-garded,astheconcentrationsofmycotoxins(thetoxicmetabolicproductsformedfrommoulds)tobeexpectedinindoorareasaresignificantlybelowtheconcentrationsconsideredacutelytoxic.However,unspecificir-ritanteffectsofsomebioaerosolconstituents,whichcanleadtosymptomssuchasirritationsofthethroatandmucousmembrane,areapossibility.

Infectionswithmouldonlypresentadangertopeoplewithasuppressedorweakenedimmunesystem.Thisatriskgroupincludesmainlypeoplewhohaveundergonebonemarrowororgantransplants,andpatientsintheacutephaseofchemotherapyoronlong-termhighdosesofcorticosteroids(substanceshavingthesameeffectascortisone).

Theextentoftheactualhealthriskfrommouldisdependentonanumberoffactors,includingtheextentandtypeofdamage,butalsoontheindi-vidualsensitivityofthepersonlivinginorusingtheroom.Atpresentthescientificknowledgeavailableisunfortunatelyinadequateformakingaquantitativerecordofthedamagewithregardtothemedicalrisk,andtherearealsonomedicalteststhatcanattributethesymptomsunequivo-callytotheexistenceofmoulddamage.

ThelatestrecommendationfromtheRobertKochInstitute,„Schimmelpilz-bildunginInnenräumen–Befunderhebung,gesundheitlicheBewertungundMaßnahmen“[“Mouldformationinindoorenvironments–investiga-tionintothefindings,healthevaluationandmeasures”](Bundesgesundhbl-Gesundheitsforsch-Gesundheitsschutz50:2007,pp.1308–1328),providesassistancewithasemi-quantitativeriskassessment.


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Inconclusionitcanbesaidthatsourcesofmouldshouldberemovedorremediedforreasonsofpreventativehealthcare,i.e.theprecautionaryprinciple,bywhichcontaminationsshouldbeminimisedbeforeillnessoccurs(theminimisationrule),shouldbeapplied.

Asexplainedabove,althoughbacteriaoftenoccuraroundmoisturedam-age,littleisunderstoodabouttheirrisktohealth.Thereareafewstudiesinwhichtheassumptionismadethatimpactsonhealthareduetothepres-enceofbacteria.Thereforetheminimisationruleshouldalsoapplyforpre-cautionaryreasonsinrespectofthegrowthofbacteriainmoisturedamage.Thebacteriaandothermicro-organismsarealsodestroyedbytheremedia-tionmeasuresindicatedformould,sothatnofurtheractionisnecessary.

Toavoidpossiblehealthrisksfrommicro-organismspropercleaningofsanitaryareasshouldofcoursetakeplaceinschoolsaswell(cf.SectionA-2).

Anotherriskthatcanarisefrombacteriaandvirusesisthetransmissionofinfectionsfromonepersontoanotherthroughdropletordirectcontacttransmission.However,thetransmissionofillnessessuchasinfluenza,scar-letfever(streptococcuspyogenes)andwhoopingcough(bordetellapertus-sis)isnotaproblemspecifictotheclassroom.TopreventthesetherelevantguidancefromtheRobertKochInstitute(e.g.HinweisefürÄrzte,LeitungenvonGemeinschaftseinrichtungenundGesundheitsämterzurWiederzulas-sunginSchulenundsonstigenGemeinschaftseinrichtungen[Advicefordoc-tors,managersofcommunityinstitutionsandhealthagenciesonreadmis-siontoschoolsandothercommunityinstitutions],updatedJuly2006.FirstpublishedinBundesgesundheitsbl44(2001):830–843)shouldbeobservedandthechildreninstructedingoodhandhygieneandcoughetiquette.

B-8 Radiation (radon)

Manhasalwaysbeenexposedtonaturalradiation.Thisradiationismadeupofexternalradiationfromspace(cosmicradiation)andnaturalradioac-tivesubstancesinrocksandsoils(terrestrialradiation)aswellasinternal

Airhumidifiersandalsoindoorfountainscancontributetothespreadofgerms,if equipment is not regularly cleaned and the humidifier water not regularlychanged.Becauseoftheriskofmicrobialcolonisationthereshouldbenohumidi-fiersorindoorfountainsinschools.

Are air humidifiers a hazard inside schools?


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radiationfromnaturalradioactivesubstancestakeninwithfoodorfromtheair.

Asubstancethatarisesfromtheradioactivedecayofnaturallyoccurringuraniumorthoriuminrocksistheradioactivenoblegasradon.Itisanaturalradioactivenoblegaswithahalf-lifeof3.8dayswhicharisesfromtheradioactivedecayofuranium(half-life4.5bn.years)oritsdaughterproductradium-226(half-lifeapprox.1600years).Itiscolourless,tastelessandodourlessandoccursparticularlyinareaswithgraniterock.Asagasitmoveseasilythroughthesoilandpenetratesfromthesoilairthroughcel-larwallsandfoundationsintobuildings.Ifradonescapesfromthegroundintotheatmosphereitisveryrapidlydispersedintheoutsideair,sothatsignificantlylowerconcentrationsarepresentintheoutsideairthaninsoilair.Normalconcentrationsintheoutsideairarebetween10and30Becquerel(Bq)/m3(1Bqdenotesoneradioactivedisintegrationpersecond).InGermanytherearesomeregionswithaparticularlyhighradoncon-tentinthesoil.TheseincludesomepartsoftheBavarianForest,theBlackForest,theFichtelMountainsandtheErzgebirge(OreMountains)aswellastheEifelregion.(TheFederalOfficeforRadiationProtection’s“radonmap”(availableat:http://www.bfs.de/de/ion/radon/radon_boden/radonkarte.html)providesinformationontheradon-contaminatedregionsofGermany.)

Owingtoitsalpha-radiatingdecayproductsinhaledradonleadstoheight-enedradiationexposureofthelung.Thisincreasestheriskoflungcancer.AftertobaccosmokeradonisregardedasthesecondmostcommoncauseofcasesoflungcancerinGermany.Theleveloftheriskofdevelopinglungcancerriseswiththeleveloftheconcentrationofradoninindoorairandwiththelengthoftimespentintheroom.Accordingtotheresultsofepi-demiologicalstudiesoftheresidentialpopulationofSweden,EnglandandGermanytheriskoflungcancerincreasesbyaround10%whentheradonconcentrationrisesby100Bqperm3.Thismakesradonthemostimportantindoorcarcinogen.

Inthecaseofnew-buildsinradon-contaminateddistrictsappropriatestructuralmeasuresshouldbeincludedinthedesigntoreducetheradonriskinsidethebuildings.Forexample,groundsourceheatsystemssuchasthoselikelytobeusedincreasinglyinenergy-efficientnewschoolbuildingsinfutureshouldbesowellsealedthatradonfromthesoilcannotentertheheat-exchanger.Inexistingbuildings,intheviewoftheFederalOfficeforRadiationProtection,measuresshouldbecarriedoutforconcentrationsabove100Bqperm3,bearinginmindthepossiblerelationship.Increasingtheventilationintheroomisacheapmeasurethatcanbecarriedoutintheshorttermtoreduceradonconcentrations.


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PART C: Structural and indoor climate requirements

Thefollowingsectionsaddressthehygiene-relatedrequirementswhichmustbelaiddownforconstructionproductsandmaterialsusedinfixturesandfittingsforindoorareasinschoolconstructionorrefurbishmentprojects,fol-lowedbygeneralaspectsrelatingtoindoorclimateandventilation.

C-1 Structural requirements, fixtures and fittings for indoor areas

Since1989therequirementsforconstructionproductswhichrelatetohealthandenvironmentalprotectionhavebeenanchoredinlawintheECConstructionProductsDirective(Directive89/106/EEC).InGermanytheDirectivewasimplementedbytheConstructionProductsActin1992.Althoughbothrulingslaydowntheframeworkforhealthprotection,theirpracticalimplementationinstandardsandregulationsisstillpartlybeingworkedout.TheCommitteefortheHealth-relatedEvaluationofBuildingProducts(AgBB)whoseofficeislocatedintheGermanFederalEnvironmentAgency(UBA)wasfoundedin1997withtheaimofminimisingemissionsofchemicalsfromconstructionproducts.InthefollowingyearstheAgBBdevelopedaschemeforevaluatingemissionsfromvolatileandsemi-volatileorganiccompounds.Between2002and2004this“AgBBEvaluationScheme”wastestedwithaviewtopossiblyimplementingitinpractice.Theevalua-tionschemeclosesamajorgapwhenverifyingthefitnessforuseofacon-

structionproduct.Aconstructionproductisconsidered“fitforuse”ifitsatisfiesthetechnicalrequirementsanddoesnotimpairthehealthoftheindoorusers.

Likeothertestingcriteria,includingforexamplerecipespecificationsandtheexclusionofcertainhazardoussubstances,theAgBBschemealsoformsanintegralpartoftheprinciplesforevaluatingthehealtheffectsofconstructionproductsinindoorareas,whichservetheGermanInstituteforConstructionEngineer-ing(DIBt)asabasisforgrantingnationaltechnicalapprovals.TheGermanMarkofConformityisthelabelforconstructionproductswithnationaltechnicalap-proval(seeFigure1).

Bild1:„Ü-Zeichen“(Muster,

Inschriftenkönnenvariieren)


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Theadditionalnote“EmissionscheckedforconformitywithDIBtcriteria”indicatesthatanexaminationaccordingtotheAgBBschemehasbeencar-riedout.ThefirstconstructionproductwhichtheDIBtapprovedafteranemissionstestin2005wasatextilefloorcovering.Sincethentheinstitutehasapprovedrubber,PVCandlinoleumfloorcoveringsandlaminatefloor-ings,usingtheemissionstest.Moreconstructionproductswillfollow.

IncomparisontotheAgBBscheme,thespecificationsfortheBlueAngellabelforemissionsfromvolatileorganiccompoundsarestricter,thatis,theproductsmustcontainmuchlowerconcentrationsofthetestvalues.Inaddition,strictrequirementsalsoapplytoothersubstances,e.g.formalde-hyde,whichtheAgBBschemedoesnottakeintoaccount.

Inconclusion,itcanbesaidthatconstructionproductswhichhavepassedthehealth-relatedassessmentaccordingtotheAgBBschemesatisfythestatutoryminimumrequirements.TheBlueAngelincorporatesfurtherre-quirementsregardingenvironmentalandhealthprotectionandisavailableforconstructionproductswhichhavenotyetbeentestedinaccordancewiththeAgBBscheme.

C-1.1 Building shell

Theusualconstructionproductsforthebuildingshell(mineralbuildingmaterials,woodandmetal)donotposeanydangertotheoccupantsandbuildingusers.Byanalogythisalsoappliestomanyrenderings,paints,wallboardsandceramictiles.However,someoftheseconstructionproductscontainconstructionchemicaladditiveswhichmustbeconsideredsepa-rately.

Todayselectinglow-emissionconstructionproductsismorenecessarythanever.Stricterrequirementsforsavingenergymeanthatbuildingenvelopesaremadeincreasinglyairtight.Withoutadequateventilationtheeffectcanbetocreateanaccumulationofchemicalandbiologicalsubstancesreleasedintotheindoorair.Using low-emission constructionproducts aswell as increasing the ventilationcanhelptopreventthis.ProductswiththeÜMarkhavebeentestedforpollutantsandfulfilthestatutoryminimumrequirements.

ProductswiththeBlueAngelmarkandaddednote“weilemissionsarm”(lowinemissions)or“weilschadstoffarm”(lowinhazardoussubstances)areevenmoresuitable.


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Thespecificpropertiesofbuildingmaterialsusedforthebuildingshellsofschoolsareoutlinedbelow.Particularlyproblematicmaterialsintermsofhygieneareaddressedbywayofexample.

Concreteisbyfarthemostcommonbuildingmaterialinbuildingshells.Itconsistsofcementasabindingagentandnaturalaggregatessuchassandorgravel,whichhardentoformastone-likemasswhenmixedwithwater.Bothconcreteandcementandcertainaggregatesarestandardisedortestedfornationaltechnicalapprovaliftheydeviatefromthestandard.Inthese“certificatesoffitnessforuse”possible,harmfuleffectsonhealthortheenvironmentareconsidered.

Bricks,lime-sand bricks,concrete blocksandporousconcreteblocksandthewallandrenderingmortarrequiredtobuildwiththemareoftenusedfortheexternalmasonry.Wallbricksareformedfromclay,sand,limestoneandwater,towhichsmallquantitiesofauxiliarymaterials,e.g.porosityenhanc-ingagentsareadded,andfiredattemperaturesofover1,000oC.Inthefiringprocessorganicpollutants,alsointroducedintothe“mouldedbricks”whenresiduesareused,aredestroyed.Thereforeoncefired,bricksdonotposeanyhealthriskatallasarule.

Lime-sandbricksareproducedfromlime,sandandwaterandhardenedattemperaturesof160-220oC.Giventhesebasematerials,theydonotcauseanyhealthproblemseither.Similarly,theinformationonconcretegivenaboveappliestoconcreteblocksandporousconcreteblocks.Heretoothegeneralpointshouldbemadethatthemajorityofwallbricksareregulatedbystandards,andthatdeviationsfromthestandardsaredealtwithaccord-ingtotheproceduresfornationaltechnicalapprovaldescribedabove.

Eventhegasconcreteandporousconcreteblocksinpopularusetodayaspartofenergysavingimprovementsinconstructionarefreeofadditivesandposenohealth-relatedrisk.Thisisnotthecasewithexternalwallswhicharebuiltusinguprights(wood,usuallysteelinschools)withcavitiesinbetweeninordertosaveenergy.Thesearethenfilledwithinsulatingmaterialsandhaveonlyplankingmadeofplasterboardorsimilarsubstanc-esandavapourbarrierbeneaththisattachedontheinside.Insulatingma-terialscancontainchemicalslikeformaldehydeand/oralreadybecontami-natedbymicrobesbeforedeliveryonsite.Thisdoesnotnecessarilycauseindoorairpollutionlatersincethevapourbarrier,provideditissealedandinstalledcorrectly,alsohelpstopreventpollutantsenteringtheindoorair.

Problemsonlyarisewhencracksandleaksemergeinthewalls,allowingsubstancesfromthecavitiestogetintotheindoorair.Problemsalsooccurifdamppenetratesthecavitiesduringconstructionorlateronandcan-notdryoutanymore.Microbescanthengrowconcealed,whichcanhave


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detrimentaleffectsonthehealthoftheusersoftheindoorareas(cf.SectionB-7).Therefore,particularcaremustbetakenineverydaypracticetoensurethatnodamageiscausedbydampgettingintocavitywallconstructions.

Mortarforwallsandrenderingismadefrommaterialsbondedwithcementorlimewhichhardenwhenwaterisadded.Aswellasaddedmaterialssuchassand,gravelorlimestone,arangeofauxiliarymixingmaterialsisused,butsincetheproportionsaresmall,theyareratherinsignificantasregardshygiene.

Woodisthebuildingmaterialmanhasusedforlongestandwhich,asarenewablerawmaterial,hasalwaysbeenavailablealmostanywhere.Sincewoodisflammableandsusceptibletoanimalandplantpestshowever,itisimportanttofollowcertainruleswhenusingwoodinconstructiontopreventinfestationfrominsectsorfungiwhichdestroywood.AccordingtoDIN68800-2“Woodpreservation–Part2:Preventiveconstructionalmeas-uresinbuildings”,todaybuildingscanbeconstructedinsuchawaythatload-bearingtimbercomponentsandbraces,includingtheroofstructure,donothavetobetreatedwithwoodpreservativesiftherelevantcompo-nentsarevisibleorpermeabletoliquids,gasesandinsects.Thetimberscanbepre-treatedbyphysicalprocesses(thermaldrying)sothatonlyasmallamountofmoistureremainsinthewood.Moreover,ifthisremainsthecaseinthebuildinglateron,itwillatleastbeverydifficultfororganismswhichdestroywoodtogrowthere.Itishowevertruethatdispensingwithchemi-calwoodprotectionrequirescarefulplanningandexecutionandcanlimitthechoiceofmaterials.

Iftheparticularconstructiondemandsofabuildingmeanthatpreventivetreatmentwithwoodpreservativescannotbeavoided,onlytechnicallyap-provedwoodpreservativescanbeusedonload-bearingcomponentsandbraces.

Withintheframeworkoftheapprovalproceduresforthesekindsofmateri-als,theireffectsonhealthandtheenvironmentaretestedandassessed,tak-ingaccountoftheirintendeduse.

Itcanbepresumedthattechnicallyapprovedwoodpreservativesposenoriskstothebuildinguserswhenusedcorrectly.

Withcomposite wood panels(e.g.particleboardorOSBpanels)whicharemainlyusedforlargeareas(e.g.asflooringpanels),aboveallthereleaseofformaldehydeemissionsshouldbeborneinmind(cf.SectionB-3).Nowadaysflooringpanelsareusuallygluedwithwaterproofadhesives(V100).Thesegluesemitlittleornoformaldehyde.Theproductsarealsoclearlylabelledfortheuserswiththe“E1”emissionsclassmarkforlow-formaldehydeorhave“formaldehyde-free”printedonthem.Withthe


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latter,isocyanateshavebeenaddedtothegluebutcannolongergetintotheindooraironcethegluehashardenedduringtheproductionprocess.Todaythelargestquantityofcompositewoodpanels(e.g.particleboardandplywoodwhichisnotgluedwithawaterproofadhesive)isstillgluedwithurea-formaldehyde-resin-basedadhesiveswhichcanmorereadilyemitformaldehydeovermanyyears(seealsoC-1.3).Formaldehydeemissionscanbereducedbymeansofcoatingsnotpermeabletoformaldehyde.WithOSBpanels,higher-orderaldehydesandcarboxylicacidsinparticularcanproduceunpleasantodoursintheindoorair.Nowadaysusingbiocidesincompositewoodpanels(V100G)isnolongerpermittedinindoorareas.

Withmetalsusedinbuildingshellsadistinctionmustbemadebetweenironorsteelandnon-ferrousmetalssuchasaluminium,zincorcopper.Theyposenoproblemasregardshygienesincetheyemitnopollutantsintotheindoorair.However,thisappliestothemetalsthemselves,nottotheircoat-ingsorvarnishes.Essentially,materialswhicharepowdercoatedexfactory(e.g.radiators)areemission-free.

C-1.2 Extensions and conversions

Emissionsfromconstructionproductsdonotalonedetermineindoorairquality.Materialsusedinfixturesandfittingsalsoplayapart.Therangeofproductmaterialsusedinindoorareasisjustasvariedasthatofthemateri-alsusedinbuildingshells.Itisalsothecaseherethatusingeco-friendlyandlow-emissionproductscannoticeablyreduceindoorairpollution.

Therecommendationslistedtogetherbelowcanserveasinitialinformationforworkdonebyspecialistfirmsandin“self-help”situations.Obviously,aswellastheiradvice,therecommendationsforuseandmanufacturer’sinstructionsonthepackagingmustbefollowed.

Besidestechnicalapprovalwhichregulatesthehealth-relatedfitnessforuseofconstructionproducts,theBlueAngelindicatesparticularlylow-emissionconstructionproductsandfurnishingsusedinindoorareas(cf.Table7).Inordertodeterminethehealtheffectsofvolatileorganiccompounds(VOCs),theBlueAngelalsousestheschemeforassessingconstructionproductsintermsofhealth(AgBBscheme)withmanyproducts.However,therequire-

Extensionsandconversionsinschoolbuildingsshouldprimarilybeundertakenbyspecialistfirms.Sinceteachers,parentsandpupilsareincreasinglyresortingto“selfhelp”inviewofthefinancialsituation,expertsshoulddefinitelybecon-sultedbeforethiskindofworkisbegun.


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mentsforthemaximumvaluesforTVOCs(totalvolatileorganiccom-pounds)andSVOCs(semi-volatileorganiccompounds)aremuchstricter.WiththesetheBlueAngelreducestheamountofpollutantspermeatingtheindoorairandcontributestowardspreventivehealthcare.

Tabelle 7: The Blue Angel for low-emission products

Criterias for Blue Angel label Awarded products

RAL-UZ 12aLow-emissionpaintsandvarnishes

Clearandcolouredpaintsandvarnishes,glazes,primers,radiatorpaints,etc..

RAL-UZ 38Woodandwood-basedproducts

Furniture,parquet,laminate,linoleum,panels

RAL-UZ 76 CompositewoodpanelsParticleboard,fibreboard,floorboards

RAL-UZ 102 WallpaintsEmulsionpaints,latexpaints,Mixingpaints,silicateemulsionpaints

RAL-UZ 113Floorcoveringadhesivesandotherinstallationmaterials

Adhesivesforflexiblefloorcover-ings,parquet,fillers

RAL-UZ 117 Upholstery Chairs,armchairs

RAL-UZ 119 Mattresses Springcoilandfoammattresses

RAL-UZ 120 Flexiblefloorcoverings Rubberfloorcoverings,linoleum

RAL-UZ 123 Sealantsforindoorareas Silicones,acrylates

RAL-UZ 128 Textilefloorcoverings Carpets

Furthermore,therearemorelabelsoriginatinginprivateinitiativesandusedbyvariousproducersinternationally.Theseinclude“natureplus”fromnaturepluse.V.(environmentorganisation)forvariousconstructionprod-ucts,‘GUT’fromGUTe.V(theorganisationoftheEuropeaneco-friendlycarpetproducers),“EMICODEEC1”fromtheGemeinschaftEmissionskon-trollierteVerlegewerkstoffee.V(AssociationfortheControlofEmissionsinProductsforFlooringInstallation)andthe“ScandinavianTradeStandards”.Withtheselabellingsystems,thetestinginstitutionsalsodetermineemis-sionsaccordingtoENorISOstandardsorrelatedmethods.


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Varnishes:

Conventionalalkydresinvarnishescancauseconsiderableindoorairpollutionduetotheirsolventcontent(35-55%w/w)andduetothefis-sionproductsofthedryingoils(aldehydesandcarboxylicacids).Thejointrecommendationforusing“solvent-reducedconstructionvarnishes”,publishedbytheWorkgroupforInstitutionsforStatutoryAccidentInsur-anceandPreventioninConstruction(Bau-BG),theGermanpaintersandvarnishersguild,thepaintandvarnishindustryandtheGermanFederalEnvironmentalAgencyamongotherscomestotheconclusion:“Takingtheirrespectivepropertiesasawhole,dispersionvarnishesareatechnicallyequivalentalternativetoconventionalalkydresinvarnishesformostareasofapplication.Furthermore,becauseoftheirreducedsolventcontent,dis-persionvarnishesaregenerallymuchmorecompatiblewithhealthandtheenvironmentandthereforeusingtheseispreferabletousingconventionalalkydresinvarnishes.”Morerecentinvestigationsontheirfitnessforuseandemissionsperformanceconfirmthisstatement.

ManydispersionvarnishescarrytheBlueAngelmark.Foralongtimethetriedandtestedalternativestoconventionalvarnisheshavebeen“low-pol-lutantvarnishes”withtheRAL-UZ12aeco-label(max.2–10%w/wsolventcontent),whichusuallycontainalcoholsandGlycoletherinplaceofaliphat-icandaromatichydrocarbons.Duetotheirlowsolventcontent,comparablelow-pollutantvarnishescausenoticeablylessindoorairpollution.

Beforepaintingandvarnishing,acheckshouldbemadeonwhethertheworkrequiresusingvarnishes,oremulsionpaintscouldbeused instead.Emulsionandlatexpaintsarethepaintssuitableformineralsubsurfaces(wallsandceilings).

Low-pollutantvarnishesorwoodglazeswiththeBlueAngellabelarethemostsuitableforprotectingthesurfacesofnon-load-bearingtimbersinin-doorareas(livingareas).Low-pollutantvarnishesforprotectingthesurfacesofwoodencomponentsorobjectsexposedtotheweatherarealsosold.

Surfacetreatingagentswithahighsolventcontentshouldnotbeusedforvarnishingparquet.Water-basedsurfacetreatingagents(waterseals)basedonacrylicorpolyurethaneresinshouldbeusedinstead.

What must be noted when using varnishes in renovations?


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Wall paints, (emulsion paints, silicate paints):

Emulsionpaintsaregenerallyheldtobeeco-friendly.Basicallythisistrueforthemainingredients:water,fillers(e.g.chalk),titaniumdioxideasapigment(provideditisproducedaccordingtotheECDirective)andbind-ers.However,emulsionpaintscannotbeproducedfromtheseingredientsalone.Useableemulsionpaintsneedvariousadditivesaswellandtheycontainpreservatives.Ifalotoftheseareused,theycancauseindoorairpollutionundercertaincircumstances.Silicatepaints,alsocalledmineralpaints,containwaterglassastheirbinderaswellasinorganiccolourings.Usingmodern(eco-friendly,low-emission)emulsionpaintsorsilicatepaintscansignificantlyreduceindoorairpollution.Theseemulsionpaints,alsotermed“ELFpaints”(emissionandsolventfree)havebeensoldbythepaintandvarnishesindustryforseveralyearsnow.Theyhavenotyetbecomeestablishedonthemarketbecausetheyaremoreexpensivethanconven-tionalemulsionpaints.

Floor covering adhesives:

Likevarnishes,floorcoveringadhesivesconsistoffourgroupsofmateri-als:binders,solvents,fillersandadditives.Todaymodernfloorcoveringadhesivesusuallycontainonlywaterastheirsolvent.However,theemis-sionsfromtheseadhesivescandifferintermsoftheirdifferentproductionprocessesandadditives.Forcertainbonds,forexample,parquetondifficultsubsurfaces,adhesivescontainingsolvents,evenadhesiveswithquitealotofsolvents,arestillusedtoday.Sometimes,usingtheseadhesivesinindoorareascanstillaffectpeople’shealthadverselyalongtimeaftertheirappli-

Emulsionpaintsaresuitablepaintsforcoveringlargeareasofwalls,ceilingsandfaçades.Usingvarnishesisnotnecessaryhere.

Paintsontheinsideofexternalcomponentsshouldnotadverselyaffectthewatervapourdiffusionperformanceoftheseexternalcomponents.

As farasprotectinghealthand theenvironment is concerned,only low-emissionwallpaintsshouldbeusedinindoorareas.Mattemulsionpaints,silkglossandglosslatexpaintsandsilicateemulsionpaintswhichhardlycontributetoindoorairpollutionwithvolatileorganiccompounds(VOCs)ordonotdosoatall(ELFpaints)havetheBlueAngellabel“weilemission-sarm”(lowinemissions)

Preservatives included in the contents declaration on the cans of water-basedpaintsshouldbenoted,inordertoprotectallergysufferers.

What should be considered when using emulsion paints (wall paints)?


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cation.Thereasonsforthiscanbethepoorconditionofthesubsurface(e.g.highlyabsorbentsubsurfaces),incorrectsubsurfacepreparationorhigh-boilingsolventsintheadhesiveswhichrequirealongtimetoevaporatecompletelybecauseoftheirlowvapourpressure.Topreventthisindoorairpollution,alreadyensuringattheplanningstagethatthefloorcoveringonthesubsurfacecanbelaidwithalow-emissionfloorcoveringadhesiveand,ifnecessary,includinglow-emissionfillerandprimer,isrecommended.

Thelow-emission“BlueAngel”eco-labelforlow-emissionfloorcoveringadhesiveshasbeeninexistencesinceJune2003.ThebasicawardcriteriaarebasedontheevaluationschemedevelopedbytheCommitteefortheHealth-relatedEvaluationofBuildingProducts(AgBB).TheaimoftheAgBBisauniform,comprehensible,health-relatedevaluationofconstructionproductsinGermany,withspecialreferencetoemissionsfromvolatileorganicsubstances.TheGemeinschaftemissionskontrollierterVerlegewerk-stoffe(GEV)(AssociationfortheControlofEmissionsinProductsforFloor-ingInstallation)alsoawardstheEC1markforrelativelylow-emissionfloorcoveringadhesives,forwhichtherequirementsarelessstrict.

Withfloorcoveringadhesivesbasedonemulsions,isolatedemissionscanbedetectedwhichdonotoriginatedirectlyfromthesubstancesthemselves,butaretheresultofreactions(secondaryemissions).Thesesubstancesarecarbonylcompounds(aldehydes,ketonesandorganicacids),someofwhichhaveonlybeenfoundaftertestslastingmorethan28days.Someofthesubstanceshaveverylowodour-thresholds,i.e.theycanbesmelledeveninlowconcentrationsandcouldthereforeberesponsibleforunpleasantsmellswhichinpracticeareusuallythemaincauseofcomplaint.Theoriginofthesesecondaryemissionscouldbelinkedtotheuseoftallresins(resinfrombeechtrees,isusedindustriallyinpaperadhesivese.g.)ortalloilsinadhesives.Thesecancontainunsaturatedfattyacidssuchaslinoleicacidandoleicacidwhichareknowntobeconvertedintothesubstancesreferredtothroughoxidationbyatmosphericoxygen.FloorcoveringadhesiveswiththeBlueAngelmarkcannotcontainoxidisableingredients.

Nowadays theadhesives industry sells solvent-free, low-emission floor coveringadhesives for all types of floor coverings (flexible floor coverings, carpets, par-quet).Givensuitablepre-treatmentofthesubsurface(e.g.filling),theseadhesivescanbeusedonall subsurfaces.Adhesive residues fromold coveringsmustberemovedbeforehand.

Which floor covering adhesives should be used?


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Floor coverings:

Floorcoveringsformthetoplayerofthefloor.Increasingly,concernsrelatedtoenvironmentalandhealthprotectionalsoplayapartintheirselectionbesidestechnical,functionalanddesignaspects.Itisoftennotenoughtoconsiderthefloorcoveringalonesinceitsemissionsperformancecanbeinfluencedstronglybythesubsurface,forexample,byabsorbentscreedwhichcanretainsolventsortheadhesivesapplied.Forthisreasontheentirestructureofthefloor,togetherwiththeunderfloor,thelayingtechniqueandmaterialshouldbeincluded.Onlyfloorcoveringswhichcanbedampwipedshouldbeusedifpossibleafternewbuildorrenovationsinschoolbuildings.

Textile floor coverings:

Textilefloorcoveringsshouldnotbeusedinschoolsbecauseofthecompar-ativelyhighcostofcleaningintermsoftimeandexpense(cf.SectionA-2).

C-1.3 Fixtures and fittings for indoor areas

Furniture,particleboardandotherproductsmadeofwood-basedmaterialsrepresentapotentialsourceofemissionsduetotheirnumberandtherela-

Asregardsdampwipefloorcoverings,thereisno“ideal”floorcovering.De-pendingontheintendedareaofuseandthenecessarystandardrequired,a selection shouldbemade from threedifferentproductgroups suchaswood/wood-basedproducts, flexibleandceramicfloorcoveringsthatwillenableittobeusedforthelongestpossibletime.Asregardsthecostofcareintermsoftimeandexpense,nogreatdifferencebetweentheseproductgroupscanbeexpected.

Floorcoveringsinclassrooms(notincorridors)aresubjecttoapprovalbytheGermanInstituteforConstructionEngineering(cf.C-1).ForthisreasonitisessentialtolookforthepresenceoftheÜmark(seeFigure1,SectionC-1)whenpurchasingfloorcoverings.

SincethenithasbeenpossibletoawardtheBlueAngelmark“weilemis-sionsarm”(lowinemissions)toarangeoffloorcoverings:rubberandlino-leumcoverings,parquet,corkandlaminate.

Ceramicfloorcoveringsshouldbeusedanywherewheretheymustprovedurablegivenconstant,heavyuseandfrequentcleaning(e.g.sanitaryfa-cilities,cf.SectionA-2).

Which floor coverings should be used in schools?


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tivelylargeareatheyoccupyinteachingareas.Thevarietyoftheproductsusedinindoorareasandthechemicalproductsusedintheirmanufacturehasincreasednoticeablyinrecentyears.Thusfurnitureandwood-basedmaterialscancontributetoindoorairpollutiontoaveryvaryingextent.

Wood-basedmaterials(particleboard,coatedparticleboard,woodcoreplywood,veneers,fibreboard)andproductsfromwood-basedmaterialssuchasfurniture,doorsandpanelsareamajorsourceofformaldehydeinindoorareas.Thereleaseofformaldehydeislimitedtothesekindsofparti-cleboardandotherwood-basedmaterialswhichhavebeenmanufacturedusingadhesivesbasedonurea-formaldehyderesins(cf.SectionB-3).Onlylow-formaldehydeorformaldehyde-freefurnitureproductsshouldbeusedinschools.

Withlong-livedproductssuchasschoolandofficefurniturewhichcanhaveaconsiderableeffectontheindoorairoveralongerperiodoftime,anindicationthattheproductsarelessharmfultohealthandtheenvironmentisenormouslyimportanttotheuser.Buildingontheresultsofearlierre-searchprojectsbytheGermanFederalInstituteforMaterialsResearchandTesting,extendedbasicawardcriteriaweredevelopedfora‘Low-emissionfurniture’eco-label.Thesebasicawardcriteriawhichstillapplytodayarebasedontheproductlifeoffurnitureitems.Anessentialrequirementlimitsemissionsfromfurnitureitemsintotheindoorair.

TheDeutscheGütegemeinschaftMöbele.V.(GermanFurnitureMakersQualityAssociation)awardsaqualitymarkforqualityfurniture(RALmark).Incontrasttotheeco-label,withRALlabels,itisfirstandforemostthematerialsused,theirtreatmentandprocessingandcompatibilitywiththeenvironmentandhealthwhicharetestedonthebasisofexistingstatutoryregulationsandtherelevantstandards.Theapplicationareaofthequalitymarkincludesschoolfurniture.

Purchasing items of school furniture which are largely made of woodshouldbebasedontherequirementsforawardingtheeco-labelRAL-UZ38(seeTable7,SectionC-1.2).

It is also recommended that, when purchasing furniture which is mademainly of materials other than wood, products which fulfil the require-mentsoftheGermanFurnitureMakersQualityAssociation(RAL-RG430)es-peciallyasregardstheirfitnessforuseanddurabilityshouldbeconsidered.

Inindividualcasesa“furniturepassport”isalsoavailablewhichgivesinfor-mationaboutthetestresultonpossibleemissionsfromtheproduct.

What should be considered when purchasing school furniture?


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C-2 Building climate

C-2.1 General physiological requirements

Humanbeingsrelyoncomplexregulatorymechanismstokeeptheirbodytemperatureconstantindependentlyoftheambienttemperatureasfaraspossible.Theyonlyachievethisaimofmaintainingaconstantbodytemperatureof37oCiftheheattheydevelopmatchesthetotalheattheygiveoff.Hypothermiaandoverheatingareunlikelytooccurifthebalancebetweenheatproductionandheatlossismaintainedandtherearenosub-stantialvariations.Thebody’sheatproductiondependsprincipallyontheperson’sactivitylevel(seeTable8).Heatexchangewiththesurroundingsisdeterminedaboveallbyheatlossthroughtheskin.

Table 8: A person’s metabolic heat production when resting or taking part in some typical activities

Activity Heat production, watt/person

Rest (basic metabolic rate) 80

Sitting activity (reading, writing) 100–125

Light activity (laboratory) 150

Moderately vigorous physical activity (climbing stairs etc.)

170–230

Vigorous physical activity (competitive sport, construction work)

400–600

Thefollowingfactorsinfluencetheheatexchangeofhumanbeingswiththeirenvironment:

Thermalconduction(e.g.throughcontactwithfurniture,floorsetc.)

Convection(heattransfer,e.g.viaaircurrents)

Evaporation(constantwaterevaporationthroughskinandmucousmembranes,occasionalevaporationthroughsweating)

Heatradiation(e.g.heatemissiontocoldersurfaces)

The(purelyphysical)processofheatexchangewiththesurroundingsisalsosubstantiallyinfluencedbytheschoolpupils’clothes.


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Underthethermalconditionsusuallyencounteredinsocialareas90%oftheheatisexchangedbyconvectionandradiation.Onlyatelevatedambienttemperatures(at27oCandabove)orduringvigorousactivities(P.E.lessons,playingontheplayground)isasignificantproportionofheatlostthroughevaporation.Convectionandradiationareinvolvedinheatexchangetoalmostthesameextent.Forthisreasonthetemperaturefeltbyhumanbeings(=operativetemperature)canbecalculatedasanarith-meticalmeanvalueofthetemperatureofthesurroundingareas(radiatedtemperature)andairtemperaturewithreasonableaccuracy.

Thetypicalsituationsinschoolswhichcanbelinkedtothermalloadin-cludeaboveall:

Warmconditionsatthestartoflessonsduetoincreasedheatlossafterbreaktimeactivity.

Uncomfortablywarmconditions,e.g.nearwindowfrontagesduetoincreasedabsorptionofradiatedheat(solarradiation,radiator).

Uncomfortablywarmconditionsatlessonstartduetointenseheatfromsolarradiationandnoactivesunprotectioninindoorareasfacingeast.

Uncomfortablywarmconditionsatlessonstartduetooverheating,solarradiationintheafternooninindoorareasfacingwest(evennorth-west)andduetoinactiveornon-existentsunprotectionandnocoolingduringthenightorearlymornings.

Riseinoperationaltemperatureduringheatwavesinsummer.

Riseinoperationaltemperatureandrelativehumidityduringlessonsduetoheatandwatervapourlossfromtheoccupantsinsituationswithinadequateventilation.

Uncomfortablycoldconditions,e.g.nearwindowfrontagesduetoincreasedthermalradiation(coldoutsidewall)orincreasedconvection(draughts).

Uncomfortablycoldconditionsinthemorningsduetolatestartofheatingfollowingovernightdropintemperature(heatingsystemonnightsetback).


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C-2.2 Technical requirements

Structuralandtechnicalprerequisitestoensureperfectindoorairqualityandagoodbuildingclimateinschoolbuildingsalsoincludeafavourablesituationandsizeoftheschoolsiteintermsofurbanplanningandmicro-climate.Theseincludeareasonableamountofsunshine,hardlyanyeffectsfromthewindorturbulence,nolargeemissionsourcesintheimmediatevicinityoftheschoolandaquietlocationawayfromtraffic.Alsonecessaryaregoodbuildinggroundandagoodarchitecturalsolutionforthebuild-ingitselfwhichtakesappropriateaccountoftherequiredsize,locationandfixturesandfittingsoftheteachingroomsandallotherfunctionalrooms.

Forseveralreasonsprotectingtheclassroomsfromheatloadinsummerasaresultofsunlightoverheatingindoorareasandhighexternaltempera-turesisbecomingincreasinglyimportant,thatis:

Inclassroomsarelativelylargenumberofpeople(particularlywithlargerclasses)occupyafairlysmallspaceduringlessons.Theresultisaheatlossthathastheeffectofinternalheatload.

Comparedtothepast,inmodernschoolstheceilingsinindoorareasarenowlowerthantheyusedtobeforcostreasons.Highceilingsarenolongercommon.Thisreducesairvolumeandthepossibilityofphysiologicalheatlossthroughconvection.

Fordesignreasons,largerwindowareashavebecomeestablishedinmodernschoolbuildingarchitecture.However,insummerthesecangiverisetounwelcomesolarradiation.

People’s thermal comfort is influenced above all by air temperature, ambienttemperatureandairmovement.

Physically comfortable operative temperatures (for classrooms accordingtoseasonandasafunctionofexternalair temperaturebetweenapprox.20–26oC)shouldbemaintainedthroughouttheyearasfaraspossible.

Walls,floorsandceilingsmustbedesignedinsuchawaythatnounpleas-antthermalradiationexchangewithcoldsurfacesoccurs.

Draughtsshouldbeprevented.

Individualclothingshouldbesuitablefortheseasonalandspatialcondi-tionsandmovement(academiclessonssittingdown,P.E.lessonsetc.).

What are the physiological requirements of human beings which must be considered in teaching rooms?


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Thinpartitionwallsand(forsoundpurposes)suspendedceilingswithalmostnocapacitytoabsorbheathavebecomecommoninteriorfix-tureswiththeresultthatinsummeranunwelcomeamountofheatisgeneratedinindoorareas.

Inaddition,thereisthefactthatthepossibleeffectsofclimatechangewhichareonlystartingtobefeltnow,willposeafargreaterproblemforfuturegenerationsofschoolpupilscomparedtotoday.Conservingheatinthewinterwillperhapsnolongerbethemainproblem,butpreventingindoorareasoverheatinginsummer.

Thegreatnumberofcausesmakespeopleassumethattherearealsomanyinfluencingfactorswhichmakeitpossibletocountersolarradiationinsummereffectively.Someofthesefactorsaredescribedinmoredetailinthefollowingsections.

Buildingorientationtogetherwiththeorientationofthemainbuildingfaçadescontainingwindowsarecrucial.North-southfaçadesperformfavourably,east-westfaçadesunfavourably.Contrarytopopularopinion,southfaçadesarenotgreatlyirradiatedbysunlightinsummerbecausethesuninthesouthatitszenithisperpendiculartotheearthatmiddayandthereforeonlyshinesonthefaçadeatanangle.Ontheotherhand,westfaçadesareaffectedbyalmostdirectsolarradiationwhenthesunislowerintheafternoon,causingconsiderableproblemsinwest-facingindoorar-eas.Moreover,duringsummerafternoons(fourtofiveo’clock)theexternalairtemperaturesarealsoattheirhighest,meaningthatalmostnoneoftheheatindoorscanbe“extractedoutside”insummer;ventilatingtheindoorareasatthistimebringsmoreheatintotheclassrooms.Thesameappliestoeastfaçadesduringthemorning.Mostindoorareasfacingeastwardshavealreadybeenwarmedupbeforethestartoflessonsorareheatedupatthestart.Incontrasttowest-facingindoorareas,thosewhichareeast-facingcanbewellventilatedinthemorningsbecausetheexternalmorningairisstillrelativelycoolinsummer.North-facingindoorareasreceivetheleastamountofsolarradiationandonlydiffusealmostneverdirectradiation.However,diffuseradiationgivesnorth-facingindoorareasexcellent,natu-rallightwithnoglareandforthisreasonartstudiostendtofacenorth.Rooflightsreceiveveryhighamountsofsolarradiationinsummer.How-ever,north-facingwindowsarerarelyusedinenergysavingconstructionmethodsbecausepeoplewanttomakeuseofthesunasapassiveenergysourcetowarmindoorareasinthewinter,autumnandspringmonths.

Thesize of the transparent window area playsacrucialroleinheatinginsum-mer.Façadeswithglazingproportionsexceeding40-50%arenottoberec-ommended.Togetherwiththethennecessarysun-protectiondevices,theycostseveraltimestheamountofnon-transparentwallsmadeoftraditionalbuildingmaterials.


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Dependingontheorientation,largeareasofglassrequiresun-protection devices.Asun-protectiondevicemustbeexternalinordertobeeffectiveinenergyterms.Deviceslocatedindoorshavenoenergy-relatedeffectasarule;atbest,theycanshieldagainstglarebutoffernothermalprotec-tion.Sun-protectiondevicescanberigidormoveable.Generallyarigiddevice,e.g.intheformofacanopy,isonlyinthecorrectposition(ifatallnecessary)ifsouth-facingbecausethecanopypreventsverticalradiationtherefromthesunatitszenith.Atthesametime,however,fixedsun-protectiondevicesreducetheamountofdaylightcomingintoareasfurtherbackinside.Eastandwest-facingwindowsneedmoveabledevices.Nosunprotectionisneededfornorthfaçades(butitisfornorth-eastandnorth-westorientationsinsummertopreventindoorareasheatingupintheearlymorningsandlateafternoons).Moveabledevicescanbecontrolledautomaticallyormanually.Theyshouldbeautomaticallycontrollableforeastfaçadesbecausethesensorstherehavetorespondasearlyasshortlyaftersunrise(atapprox.fiveo’clock).Solarcontrolglassisnottoberecom-mendedinschoolbuildings;glasswithhighlighttransmission,moderate,non-heat-gain-optimisedgvalue(totalenergytransmissionlevel)oftheglazingandexternallylocatedsunprotectionispreferable.Thesun-protec-tioneffectisindicatedbythe“totalsolarenergytransmittance”;itmustbeverifiedforthesun-protectiondevicetogetherwiththeglazingbyatestcertificatefromanaccreditedtestinginstitution.

Glass atria or foyers with glass roofsrequiretheinvolvementofbuildingphysicsexpertstobeproperlydesignedandconstructed.Insummerhorizontalglassroofsreceivethestrongestradiationofallbuildingcomponents.Thiscanbeasmuchas1,000W/m2atmiddayinextremecases.Sun-shadingintheformofexteriorawningsorsimilarareindispensablehere.However,theawningsmustnotobstructtheroofopeningsforventilationorsmokeextraction.Externalsun-protectiondevicesmustbeprotectedagainstdam-agefromsnoworfreezingwaterinwinter.Thesameappliestophoto-voltaicelementsinstalledintheroof.Onthereversesidethephotovoltaicelementsemitrelativelystrongheatflowstowardstheinside.Thisisoftenunderestimated;thesehavetheunwelcomeeffectofadditionalpowerfulradiatingceilingheatersinthesummeriftheyarenotputupatadistanceandback-ventilatedwithairfromoutside.

Heat-retaining componentsinbuildinginteriors(solidwallsandceilings)absorbindoorheatinsummer.Theindoorcomponentsareimportant;theretain-ingeffectoftheremainingsectionsofexternalwalls(nearthelargeareasofglass)isnegligible.Itispossibletopreventsolarradiationcominginfromoutsideinsummerbyhavingindoorcomponentsoftherightdimen-sions.Iftheyareintendedtoservetoretainheat,thesurfacesofsolidindoorcomponentsshouldnotbecoveredwithheat-insulatingcoatings


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becauseotherwisetheradiatedenergycannotbeabsorbed.Carpetsorhangingrugsreducetheretainingcapacityofaconcreteslabforexample.Usingwhatareknownasphasechangematerials(PCMs)canhelptopre-ventclassroomsoverheatingduringtheday.Dependingonthesettransi-tionpoint(e.g.25oC),thesematerialswhichresemblewaxaremelted,andtheheatwhichisabsorbedwithoutthetemperatureofthematerialsrisingfurthercanbe“discharged”duringthenightthroughventilation.

Theheatretainedintheindoorcomponentsduringthedayhastoberemovedfromtheinterioragainthroughincreasednight ventilation.Ifthisdoesnottakeplace,theindoortemperaturekeeps“swinging”higherdaybydayinsummer.Fortunately,inourclimatetheexternalairtemperatureatnightisusuallyloweveninsummer(thisisoftennotthecaseininnercitylocations)anditispossibletocoolindoorareasbyventilatingthematnight.However,largeopeningswhicharedesignedtobesecureagainsttheweatherandintrudersorcanbemonitoredbythecaretakermustbeinplacetoensureschoolindoorareasareairedatnight.Alternatively,ven-tilatingindoorareasearlyinthemorningsinsummerwhenhighoutdoortemperaturesareexpectedcancertainlybeeffectiveandpossiblyeasiertoorganise.

Evidently,protectingschoolindoorareasfromoverheatinginsummercanbeachievedthrougharaftofmeasures;notallofthesemustbeadoptedatonceinindividualcases,rather,theyshouldbeselectedsinglyorincombi-nationasappropriate.AmongothersDIN4108(Part2)givesguidanceonthis(duetothehighinternalloadresultingfromthelargenumberofpeopleinclassroomsitisnotexpectedthatthemaximumtemperaturesgiveninDIN4108(Part2),includingtheshortexceedancetime,willbeadheredto).

Permissibleindoorairtemperaturesinschoolsandofficesinsummercauseregu-lardiscussionsbetweenbuildingoperatorsandthoseaffected.However,accord-ingtotheWorkplaceOrdinancethere isarecommendation (notamandatoryregulation)thattheindoorairtemperatureintheworkplaceshouldnotexceed26oC.Yetthegeneralbuildingphysicsprinciplethatinourlatitudesitmaybehotterforshortperiodsduringthedayinsummerapplies.Itispossibletoadheretothisbuildingphysicsprincipleinalmosteverycaseiftheinfluencingfactorsreferredtointhissection(C-2.2)areconsistentlyborninmindthroughoutthedesignphase.Strictlymaintainingtherecommended26oCwouldrequiretheuseofair-conditioningsystemsinschools.

How high can the indoor air temperature in indoor areas in schools be in summer?


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C-2.3 Ventilation technology

Free ventilation:

Thisiswindowventilation,alsocalled“free”or“natural”ventilationwherebynoventilationsystemsorotherventilationequipmentisused.

Inschoolsthepreferenceforusingfreeventilationoftenrepresentsacom-promisebetweencostandsuccess.Classroomscannotbeventilatedbywin-dowsthroughouttheyearinsuchawaythatthedesiredlimitsofthermalcomfortandairqualitycanbemaintainedatalltimes(cf.SectionC-2.1).Particularlyinwinteritcanhappenthatthosesittingnearthewindowscomplainoffeelingcoldwhenthewindowsareopenedforalongtimetoventilatetheroom.Ontheotherhand,adheringtothehygienerequire-mentsintermsofcarbondioxidemustbeensuredifpossibleduringandattheendoflessons(cf.SectionB-1).Forthisreasonitisessentialthat,eveninthewinter,classroomsareconsistentlyventilatedduringbreaktimes,aswellasduringlonglessonsoriftheclassesareveryfull.

Rooflightsandpivot-hungwindowsshouldstayopenatnightduringperi-odsofwarmweather(providedtheyaresecuredagainstbreak-in),sothattheindoorareascancooloffmoreeffectively.Howcanthewayinwhichusersventilateschoolshelptoimproveairquality?

Mechanical ventilation:

Mechanicalventilation(ventilationsystem)offerstheadvantageofmain-tainingacertainminimumnumberofchangesofairindependentofthebuildingusers.Moreover,mechanicalventilationhastheaddedenergy-relatedadvantagethatitcanbeconnectedtoaheatrecoverysystem.Theaircirculatedtotheindoorareasshouldconsistof100%freshairwithoutanyadded“recirculatedair”(“recirculatedair”referstoairextractedfromonearea,whichhasbeenfilteredandthenrecirculatedbacktotheindoorareas).Correctdesignandconstructionandoperationandmaintenancerequireapplicationoftherelevantstandardsandguidelines,inparticularDINEN13779andVDI6022.

Ventilatingregularly,ideallyusingcrossventilation.

Ventilatingregularly,ideallyusingcrossventilation.

Avoidingallowingindoorareastogettoohotortoocold.

How can the way in which users ventilate schools help to improve air quality?


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Mechanicalventilationcanhelptowardscoolingthebuildingwithinten-siveventilationatnightduringthesummermonths(cf.notesonnightventilationinSectionC-2.2).

C-2.4 Acoustic requirements

Eveninthebestschoolsteacherscannotteachiftheintelligibilityoftheirspeechsuffersonaccountofpooracousticsinthebuilding.Notonlyisitimportanttopreventtheeffectsofnoisefromoutside.Equallyimportantarethedesignandconstructionrequirementsinandonbuildingstoim-provetheacousticsinside.

Theacousticdesignofschoolsandteachingroomsaimstocreateopti-mumconditionsforpromotingratherthancompromisingthehealthandachievementofpupils.Thisappliestotheuseandusabilityofteachingrooms,dependingontherelevantenvironment(schoolbuildings,sur-roundingarea),butindependentofpedagogicplanningandtheindividualrequirementsofthechildren.Afurther,fundamentalaspectofthesustain-ableacousticdesignofteachingroomsisseeingacousticsasanintegral,indispensablepartofbuildingdesign.

Area of application:

Acousticdesignaffectstheacousticpropertiesoftheentireschoolbuilding,includingthebuildingitselfandtheindoorareas,thatis:

generalteachingrooms,

specialistteachingrooms(music,sportetc.),

socialareas,including

corridorsandstairways.

Onlybyconsideringtheseholistically(seeFigure1),isitpossibletoachieveoptimumworkingandlearningconditions.Thebuildingacousticsproper-tiesincludethesoundinsulationofwalls(externalandinternal),ceilings,roofs,doorsandwindowsagainstnoise(e.g.trafficnoiseoutsideandvoic-es,musicetc.inside),offloorsagainstimpactsound(e.g.peoplewalking,includingchairmovementetc.)andagainstnoisefrombuildingservicesequipmentandinstallations.

Thepropertiesoftheacousticsinindoorareasincludemutualspeechintel-ligibilityandthewaytheareahelpstoamplifyormufflethesounds,inparticularofspeech.


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Thelawsofphysicsresultinvaryingdegreesofinteractionbetweenstruc-turalandacousticpropertiesinbuildings.Thustheresultingsoundinsula-tionbetweenadjacentareasdependsonboththesoundreductionofthewallcomponentsandthesoundproofingintheroomsthemselves.

Acoustic parameters and values: A) Sound insulation

BuildingacousticsvaluesandtheirrespectivelimitvaluesaresetouttogetherinTables9-11.

Table 9: Required minimum sound reduction (weighted sound reduction index Rw) of components between indoor areas in school buildings according to DIN 4109

Component part between teaching rooms and..Min. sound reduction index Rw [dB]

Walls Teachingrooms 47

WallsSpecialistteachingrooms(music,sport,workshopsetc.)

55

Walls Corridors 47

Walls Stairways 52

Doors Corridors 32

Table 10: Maximum impact sound pressure level (weighted normalised impact sound pressure level Ln w) in indoor areas in school buildings, according to DIN 4109

Component partbetween teaching rooms and..

Max. normalised impact sound pressure level L’n,w [dB]

Walls Teachingrooms 46

WallsSpecialistteachingrooms(music,sport,workshopsetc.)

46

Ceilings under corridors 53


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Table 11: Maximum noise level (characteristic sound pressure level LA f) in teaching rooms caused by building services systems, installations and various systems in school buildings with reference to DIN 4109

The effect of noise in ... Max. Sound pressure level (sum level) LA, f [dB(A)]

Teaching rooms 30

Specialist teaching rooms (music, sport, workshops etc.)

35

ThevaluesinTable11onlyapplyduringtheday,i.e.duringschoolhours.Itisessentialthatstrangenoises,e.g.isolatedorrecurringvolumepeaksorvolumefluctuationsandisolated,pronouncedsoundsbeavoided.

Withreferencetosoundinsulationagainstoutsidenoise,therequirementsofDIN4109applytotheexternalcomponentsofschoolbuildings.Inpar-ticular,noisesresultingfromtrafficorothersources,whichhaverecurringvolumepeaksorvolumefluctuationsandisolated,pronouncedsoundsmustbetakenintoaccount.

B) Indoor acoustics

Traditionally,thebestknownparameterfordescribingtheacousticproper-tiesofindoorareasisreverberationtime.Thevalueswhichmustbead-heredtoaregivenaccordingtoareaandapplytotheareaswhenunoccu-pied.TheyaresummarisedinTable12.Thevaluesapplytotheusualaudiofrequencyrange,i.e.totheoctavebandsfrom63Hztoapprox.8KHz(mid-frequencies).

Table 12: Obligatory reverberation time values, including tolerance, in indoor areas in school buildings

Area type Reverberation time T in s

Teaching rooms (with a volume below 300 m3)

recommended0.5±0.05s

Teaching rooms, sports halls, gyms and swimming pools (dependent on volume)

accordingtoDIN18041“Audibilityinsmalltomediumsizedrooms”

Ahighlevelofspeechintelligibilityisimportantinschools.Therever-

berationtimesgiveninTable12thereforedifferslightlyfromthoseinDIN18041.Noise-absorbentceilingsshouldnotbeusedalonetoreducereverberationtime.Therearwallareabeneaththeceilingisalsosuitable.


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Ahighlevelofspeechintelligibilityisimportantinschools.Thereverbera-tiontimesgiveninTable12thereforedifferslightlyfromthoseinDIN18041.Noise-absorbentceilingsshouldnotbeusedalonetoreducerever-berationtime.Therearwallareabeneaththeceilingisalsosuitable.

Inlargersportshallsandareasusedforsimilaractivities,acorrectlydeter-minedreverberationtimewhichtakesaccountoftheoftenvariedusesofthehallshouldbemaintainedinanyevent.Itisrecommendedthatspecialconsiderationandtreatmentbegiventotheindooracousticsinspecialisteventandmusicareas,e.g.schoolhalls.

RecommendationsforadditionalindoorareasinschoolbuildingscanbefoundinTable13.Theydonottargetgoodspeechintelligibilitysomuchasattenuationofveryloudnoiseswhichoccurtherefromtimetotime.

Tabelle 13: Recommended reverberation time values, including tolerance, in indoor areas of school buildings (cf. Figures 2 and 3)

Raumart Nachhallzeit T in s

Corridors, stairways T=V/1000m3+0.8

IntheequationtheVisthevolumeforconnectingareas,e.g.thosesepa-ratedbydoors,inm3.Thecalculatedvaluesshouldbeconsultedforareasmeasuringapprox.100m3to800m3.ReferencevaluesforsmallorlargervolumesareshowninFigure2.

Besidesthereverberationtime,theambientnoiselevelalsodeterminestheacousticpropertiesinindoorareas.Theambientnoisesproducedoutsidetherelevantareaatleastareaddressedthroughthepropertiesinpara-graph“A”(soundinsulation).


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General advice on practical acoustic design:

Instandards,guidelines/directivesandotherliterature,thereisawealthandvarietyofbuildingdesignoptionsforallaspectsofsoundinsulation(e.g.DIN4109)andforconfiguringindooracousticconditions(e.g.DIN18041).Inmanycases,especiallyfornewbuildingsorlargerrefurbishmentsorextensions,anacousticsexpertshouldbeconsultedifpossible.

Acousticqualityasdescribedinthisguideisimportantforbothexistingandnewschoolbuildings.Withproperplanningalltheparametersreferredtocaneasilybeimplemented,usingcommerciallyavailablecomponents.This isalsotrueinthe context of the remaining structural andbuildingphysics requirements forschoolbuildings.


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Reve

rber

atio

n ti

me

Volume m3

Figure2:Indooracoustic(1–reverberationtime)andbuildingacoustic(2–soundinsulationofwallsetc.,

3–impactsoundinsulationofceilingsandfloors,4–soundinsulationofexternalbuildingcomponents

5–noisefrombuildingservicesinstallations)influencesonthequalityofschoolbuildings

Figure3:Recommendedreverberation-timevaluesasafunctionofthevolumeforcorridorsandstairways

inschoolbuildings.


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PART D: Procedures in problem cases

D-1 Basic procedures

Inthissectionexamplesofproblemcases(casestudies)arepresented.Aware-nessofproblemsinsideschools,nurseryschoolsanddaynurserieswillgener-allyberelatedtothecause,inmostcasesbecauseofsymptomsofillnessoraparticularoccurrence.However,specificenquiriesbecauseofmediareportsorroutinechecksandprecautionaryinvestigationscanalsobethecatalyst.

Inmostcasespublichealthserviceinstitutions,i.e.thehealthandenviron-mentagencies,theindustrialhealthserviceortheappropriateaccidentinsurersareinvolvedastheprimarycontactsoftheinstitutions’control-lingauthorities.Inthesecasesastructuredprocedureshouldbeexpected,generallyresultinginarationalandefficientsolutiontotheproblem,which,inthecontextofriskcommunication,shouldleadtoacceptancebythoseaf-fected.

Thesituationoftenbecomesmoredifficultifaneedforseriousactionisestablishedfrominappropriatemeasurementsandexaggeratedevaluations,andextensiveunnecessaryfollow-upinvestigationsandrecommendationsforremediationensue.

Thefollowingcasestudiesaresetoutasastructuredprocedureanddealwiththecause(e.g.healthproblems),asummaryofthesituation(Siteinspec-tion,questionsasked,buildingconstruction,files),furtheractionthroughinvestigations(readings,enquiries),evaluationoftheresults,theconsequentrecommendedactionandmeasures,andtheoutcomeachieved(continueduse,acceptance).

Thefollowingactionplan,whichclarifiestheindividualstages,canbeseenasasuggestedprocedureinproblemcases.Itdoeshoweverdependonbring-inginexpertcompetencefromthehealthauthoritiesatanearlystageandinvolvingthoseresponsible(schoolauthority,buildingauthority,industrialhealth,accidentinsurers,etc.)andthoseaffected(e.g.parents,users)equallythroughtransparencyoftheprocess;moreover,allparticipantsshouldun-derstandandacceptthestepschosenanddecisionstaken.Thisalsoincludestakingthecomplaintsandhealthproblemsseriously,makinginformationavailableatalltimes,involvingthoseaffectedinthedecision-makingprocess,andcommittingoutsideagents(measuringinstitutes,renovationcompanies,tradesmen,etc.)toqualityassurance(e.g.minimummeasuringrequire-ments),aswellascarryingoutafinalcheckandinspection(assessmentofsuccess),ifpossiblewithallparticipants.


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Diagram4:Flowchart:proceduresincasesofillness,seedoublepagefollowing.

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D-2 Case studies

D-2.1 Mineral fibres from suspended ceiling construction

Cause/authority contacted:Healthagencynotifiedbyschoolauthoritybecauseofteachers’healthproblems.

Situation:Teacherscomplainingofeyeandthroatirritationsanditchyskin.

Site inspection:Suspendedconstructionslattedceilinginthestaffroom.Fornoisecontrol,mineralwoolmatshavebeenlaidontheslatswithoutafilterlayer.Theventilationsystemblowsincomingairdirectlyintothesuspendedceilingabovetheleveloftheslatsandinsulationmats.Thereareconsider-abledustdepositsonthecupboards.

Investigations:Anexaminationoffibres(inaccordancewithVDI3492)revealedacombinationofmineralfibreswithaKIof<30andaclassifica-tioninthecategoryK2.Indoorairmeasurementsproducedarespirableinorganicfibre(WHOfibre)contentof7000/m3.

Evaluation:Theconstructionisevaluatedasinadequateandunacceptable(nofilterlayer,incomingairblowingthroughit).Theemissionoffibresissignificantlyraised(tomorethan1000fibresperm3),sincethetechnicalconstructiondoesnotmeetwithup-to-datetechnicalstandards.

Recommendations:Removethemats,observinghealthandsafetyatworkcon-ditions,andreplacewithaproblem-freematerialwithafilterlayer.Altertheairsupplyintotheroombyputtinginventsattheleveloftheslatsorbyturningofftheventilationsystem.Washsurfacesintheroomsregularly.Usevacuumcleanerswithparticulatematterfilters(HEPAfilters).

Action and outcome:Riskcommunicationwithschoolmanagementteamandstaff,explanationofthetoxicologicalevaluationofsyntheticmineralfibres.Clearreadingaftercompletionofremediation(<500F/m3).Noproblemssince.


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D-2.2 Chloronaphthalene in prefabricated school buildings

Cause/contact with authorities:Requestfromtheschoolauthority(localauthor-ity)tothehealthagencyowingtounpleasantodours,presumablybecauseofamouldattackfollowingflooddamageinaschoolcomplex.

Situation:Thisconcernsa1970sschoolcomplexofprefabricatedconstruc-tion.Waterdamageoccurredintheroomsasaresultofleakingflatroofs.Unpleasantodourshadbeenevidentforsometime,whichwereattributedtotheflooding.Mouldreadingshadalreadybeentakenbythelocalhy-gieneinstitute,showingaraisedgermcountintheindoorair.Noexplana-tionfortheunpleasantodours.Schoolchildrencomplainedofstingingeyes,burningskin,sorethroatsandheadaches.Theparentsreportedasmell“clinging”tothechildren’sclothes(“staleschool”).

Investigations:AnalysesoftheindoorairproducedanunremarkablesampleoftheusualVOCs,butwiththeunusualadditionofchloronaphthalenes(CNs)atlevelsupto50μg/m3.Furtherreadingsrevealedasignificantdependenceontemperatureandaconcentrationrangeof1–5μg/m3fornaphthaleneandbetween2and50μg/m3formono-anddichloronaphtha-lene.A“musty”odourwasrecordedbythepeopletakingsamples.Exami-nationofthematerialsamplesidentifiedthesourceoftheCNsastypeV100Gwaterproofparticleboard.FurtherenquiriestothemanufacturerrevealedtheuseofthewoodpreservativeBasileumSP-70,whichcontainschloronaphthalene,onthereversesideoftheboards.

Evaluation:Theevaluationwascarriedoutusingaprovisionallyderivedguidelinevalue(interventionvalue)of200μg/m3andanenvironmentalhygienetargetvalueof20μg/m3becauseoftheunpleasantodourandthecredibleeffectsobservedonhealth.

Recommendations:Fromanindoorhygienepointofview,becauseofthewa-terdamageanddetectionofthelocalisedmouldattack,andbecauseoftheamountsofchloronaphthalene,acomprehensiveremediation(removaloftheV100Gboards,roofrenovation)orrebuildingwasrecommended.

Action:Localcouncil,staffandparentswereinformedofthefactsinpublicbriefingmeetingsheldjointlybythehealthagencyandthespecialistagen-cies.

Outcome:Thelocalauthoritydecidedtodemolishtheschool,becauseofitsage(intendedfor20years’usewhenerected)andthehighcostofrenova-tion,anderectedanewbuildinginsolidconstruction.


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D-2.3 Odour pollution in classrooms after the long holidays

Reason/contact with authorities:Healthagencycontactedbytheschoolauthor-ityonaccountofanunusual“chemicalsmell”ineightclassroomsataprimaryandsecondaryschool.

Situation:Thisconcernsroomsintheoldpartofaprimaryandsecondaryschool,whichaccordingtotheseniormanagementis100yearsoldandhasneverbeenaffectedbyhealthproblemsorbadodoursuntilnow.Twoyearsagotheoldbox-typewindowswerereplacedwithmodernplasticwindows.Atthebeginningofthesummerholidaysthecleaningstaffpolishedthewoodblockfloor–asusual–withaliquidwax.Fromthesafetydatasheetitcanbeseenthattheproductcontainsnaphtha(petroleum,lowaromaticcontent).

Site inspection:Oldbuildinginverygoodstateofrepair,withold,wellmain-tainedwoodblockfloor.Strongodourof“floorpolish”.

Investigations:Indoorairreadingsusingactivesample-taking(NIOSHtubes)overfourhours,afterdoorsandwindowswerekeptclosedovernight.Result:veryhighsolventconcentrationsinalleightroomswithTVOCcon-tentsbetween10and23mg/m3.TheguidelinevalueRWIIwasexceededforthealkaneandaromaticgroupofsubstancesandfornaphthalene.Theprofileoftheindoorairmatchedthecompositionofthefloorwax,towhichtheintensiveodourofalkylaromaticswastracedback.Asconstitu-entsofthesolventthesehavealowerodourthresholdthanthealkanes.

Evaluation:AccordingtotherecommendationsoftheIRK/AOLGadhocwork-inggroup(cf.SectionB-2)thepollutionshouldbeclassifiedas“category5”:TVOCvaluesbetween>10and25mg/m3areclassifiedashygienicallyunac-ceptable.Usingtheroomshouldgenerallybeavoided,althoughspendingashorttimeiniteachday(lessthan1hourperday)isreasonableifmoreintensiveregularventilationmeasuresarecarriedout.Atvalues>25mg/m3theroomshouldnotbeusedatall.ValuesexceedingRWIIdemandanimmediateinspection,e.g.regardingmeasuresanddecisionstoreduceexposure.Thefollow-upreadingtochecktheindoorairqualitytakesplaceundernormaluse.

Theuseofthefloorpolishatthebeginningoftheholidayswasestablishedasthecauseoftheunpleasantodour.Thiscontinuedtohaveaneffectoverafairlylongperiod,astherewasnoactiveventilationintheholidaysafterthepolishingtookplace.Asaresultofinstallingtightlyclosingwindowsthenaturalairexchangewasnolongersufficienttoremovethesolventodourfromtheairinside,asithadbeeninpreviousyears.


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Recommendations:Sincetherewasnoalternative,itwasrecommendedthattheroomsbeusedonconditionthatparticularlyintensiveventilationmeas-ureswereimplementeduntiltheoutcomeofthecontrolreadings.

Action and outcome:Follow-upreadingswereimmediatelyarrangedundernormalconditionsofuse.TheresultsshowedTVOCconcentrationsbetween0.06and0.4mg/m3.Thenaphthalenecontaminationoftheindoorairwasbetween3and10μg/m3andthusintherangebetweenRWIandRWII.ThecomparativeTVOCreadingsunderstandardisedconditions(withoutairingbeforehandandwindowsclosedovernight)showedasignificantdrop(previously23,now1.5mg/m3).

Theresultsweresetoutinariskcommunicationtoseniormanagementandstaff,parents’representatives,educationauthorityandplanningdepart-mentandcontinueduseassessedastolerablewithstrictadherencetoven-tilationmeasures.Follow-upinspectionsinfourweekswerearranged,anditwasrecommendedthatinfutureafloorwaxwithoutaromaticcontentshouldbeused,ensuringadequateairingafterthefloorispolished.Themanufacturerwascontactedwiththerecommendationtoincludeadviceonincreasedventilationafteruseintheinstructionsandtocheckthecombina-tionofsolventsusedintheformulation,since,contrarytotheinformationgiven,aproductcontainingaromaticshadpresumablybeenused.

Twomonthsaftertheincidentthemanufacturerrepliedthatadifferentsol-venthadbeenusedintheformulationfromtheonehehadspecified.Thefaultybatchwastakenoffthemarket.


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D-2.4 Persistent indoor air pollution resulting from the use of solvent-based cleaner on woodblock floors

Cause/contact with authorities: Telephonecallfromtheheadteacher10weeksafterthoroughcleaningonaccountofaturpentine-likeodour.

Site inspection:Two-storeyextension(builtin2000)ataprimaryandsecond-aryschool,containingfourclassrooms,agrouproomandacomputerroom.Floorconsistingofunsealedwoodenboards(robust,canbesandedrepeat-edly).

Facts:Thoroughcleaningduring2003summerholidayswithC4,asolventfor–accordingtothemanufacturer–“effortlessremovalofoldlayersofwax,oil,fatandgrease”,thenhardglosswax.Sametreatmentinallroomsexceptcomputerroom,especiallystrongodourinoneclassroomonthegroundfloor.

Investigations:InitialmeasurementofVOCcontentintheclassroom,takingthrougharound600litresofair.Samplealready“overloaded”,noanalysispossible.Thefollow-upVOCreadingshowedbetween7and40mg/m3forthetotalVOCs.AnalysisofthecleanerC4showedacorrespondingspectrumofVOCs.Comparativereadingsintheoldbuildingproducednothingunu-sual.Inthefollowingyearsrepeatedreadingsinallaffectedroomsundercontrolledconditionsandinnormaluse(upto17readingsinoneclass-room).

Useoftheroomswassubjecttoastrictventilationregime,whichwasfol-lowedrelativelywell.

Outcome:Theprofileoftheanalysesremainedsimilarthroughoutandonlyfellveryslowly(alkanes,terpenes).Undernormalconditionsofusethevalueswerealwayssignificantlylower.Overthewholeinvestigationperiodtherewerenocomplaintsaboutadverseeffectsonhealth.Theclassroomwhichwasinitiallymostcontaminatedalsoretainedanoticeablesolventsmellforthelongesttime.ThelastreadingsinFebruary2006wereintheorderoflessthan1mg/m3.

Action:Despitetheclaim“Foruseonsolvent-proofflooring,e.g.unsealedwoodfloors”itisrecommendedthatthisproductshouldnotbeusedonwoodfloors,especiallywheretherearecracksandeasilyaccessiblecutsurfaces.Correspondingadvicetothemanufacturertochangetheclaimac-cordinglyhasreceivednoresponsetodate.

Recommendation:Totheschool:Continuewiththoroughairing.Useaspecial-istflooroilanalysedinalaboratorybeforehand,appliedsparinglytothesurface.Tothecleaningstaffinthebuilding:C4cleanershouldnolongerbeusedintheareaconcerned.


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D-2.5 Indoor air contamination with dibasic dimethyl esters (DBE)

Cause/contact with authorities: Healthofficeinformedbytheschoolauthorityafterabnormalindooraircontaminationestablishedbyacontractedlabo-ratory.Whendoingthis,thelaboratoryreferredtotherecommendationexpressedbytheIRK/AOLGadhocworkinggroupintheinstructionsforevaluatingindoorairpollutantstocallintheappropriateregionalauthor-ityincasesofraisedvalues.Thereadingsweretakenbecauseofcomplaintsofhealthproblemsamongchildrenandteachers.

Site inspection:Primaryschoolingoodstateofrepairwithcarpetedfloorsintheclassrooms.Unpleasant“sweet”smellinasectionofthebuildingrenovatedsixmonthsearlier.Therewerenoindicationsofthisintheotherpartsofthebuildingthathadbeenupgradedpreviously.

Facts:Inthesecondhalfof2007thispartofthebuildingwasrenovatedfol-lowingthesamepatternasothersectionstheyearbeforeandnewcarpet-ingwaslaid.Intheinvitationfortendersthearchitectexpresslyspecifiedtheuseofenvironmentallyfriendlyproducts.Aftertherenovationtherewereimmediatecomplaintsaboutbadodoursandadverseeffectsonhealth(irritationoftherespiratorytracts).Atfirsttheodourwasconsideredtoberelatedtotherenovation,andowingtothechoiceofmaterialsandtheinformationonthesafetydatasheetsitwasassessedasharmlesstohealth.Afterthecomplaintshadpersistedforsixmonthsanenvironmentallabora-torywasfinallycommissionedtotakeindoorairreadings.

Results of the investigations:Intheroomsconcerned,exceptforsignificantlyraisedconcentrationsofdibasicdimethylesters(sum∙ 1500μg/m3),anoth-erwisenormalVOCprofile(otherVOCsapprox.300–400μg/m3)wasfound.

Outcome:Theprofileoftheanalyseswassimilar(C4-C6dibasicdimethylestersbetween600–1600μg/m3)intheroomsthatwererenovatedsixmonthsearlier.Innormalusewithintensiveventilationthevalueswerelower(under100μg/m3).

Action:Inaprovisionalevaluationtheregionalauthorityresponsiblede-rivedaprovisionalguidelinevalue(interventionvalueof500μg/m3andatargetvalueof50μg/m3forthesumoftheC4-C6dibasicdimethylesters(CAS95481-62-2).Becauseoftheexcessvaluesandtheadverseeffectsonhealthreportedallsuspectedroomswereimmediatelytakenoutofuse.Furtherreadingswerearrangedtoclarifytheextentofthecontaminationandtoestablishthesource/cause,includingbycoresamplesandtestsonmaterials.Theparentsreceivedaletterinformingthemofthesituationandaquestionnairewasdistributedtofindoutaboutadversehealtheffectsamongchildrenintheroomsconcernedandinuncontaminatedrooms(controlgroup).Withinaweek230outof350questionnaireswerereturned


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andanalysed.Theseshowedahigherprevalenceofnasalirritations,sorethroatsandhoarseness,coughsandshortageofbreath,andheadachesamongthechildreninthecontaminatedroomscomparedwiththecontrolrooms.Theincreasedandunusualdisordersamongthechildrenwhohadbeenexposedcouldplausiblybeattributedtothetoxicityofthedibasicesters.Theresultsoftheinvestigationsandthesurveywereexplainedatapublicmeetingattheschool,whereparentsreportedanimmediateim-provementinthesymptoms.Asecondsurveyfollowedthreeweekslater.Bythistime,havingvacatedtherooms,thechildren’sdisordershadsubsidedandwereatthesamelevelasthecontrolgroup.

Recommendation:Roomsnottobeuseduntilthecauseofthecontaminationwasidentifiedandeliminated.AsthiswasthefirsttimethatDBEshadbeenshowntocontaminateindoorair,acorrespondingreportwassubmittedtotheFederalInstituteforRiskAssessmentinaccordancewithArticle16ChemG.Thecasewassubsequentlyexaminedfurtherwiththeparticipationoftheconstructioncompanyandthemanufacturerofthebuildingmateri-alsused.TheywereabletopinpointthecauseastheuseofapolyurethanelevellingcompoundwithahighDBEcontentinthefloorconstruction.Aftertheseexperiencestheuseofdibasicestersinindoorenvironmentsmustberegardedascritical.

Theexampleshowsthatincasesofunusualindoorcontaminationwith“new”substancesandoftheexistenceofadverseeffectsonhealththeap-propriateprofessionalinstitutionsshouldbeinformedimmediately,andthat–despitetheinstructiontouseenvironmentallyfriendlyproducts–abnormalindoorairpollution,inthiscaseevendetrimentaltohealth,canoccurtimeandagain.


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D 2.6 Health problems in a new wing of a primary school

Cause: Twoyearsafterbuildinganewschoolwingwithatotalof4class-roomsand2multipurposeroomsobvioussymptomsfirstappearedinpu-pilsandstaffattheendofSeptember/beginningofOctober.Parentsreport-edthat10childrenweresufferingfromseveretoveryseveresymptomsandthat9outof10ofthechildrenweregoodtoverygoodpupils.Thefollow-ingcomplaintswerereported:severeheadaches(6children),stomachacheandnausea(7children),peribronchitis(1child),skinrashesorunexplainedallergies(2children),redandstingingeyes(3children).Theskinreactionsextendedtothelegsandoccasionallyalsotothefaceandneck.Someofthechildrenhadalargenumberofabsences.Onechildwasexaminedbydoc-torsforatumourbecauseofextremeheadaches–withnegativeresults.Itwasnoticeablethatthesymptomsfirstarosewhentheheatingwasonandthat4ofthe10childrensatdirectlynexttotheheaters.Itwasalsostrikingthatsymptomssuchasreddeningoftheeyeshadalwaysbeguninschoolandsubsidedintheafternoon.Thechildrenwereallreceivingmedicaltreatment,andnocausecouldbeidentified.Thedoctorsruledoutorganiccauses.Theteacherscomplainedofheadachesandsorethroats.

Action:Afterthefirstcomplaintshadbeenlodgedwiththetowncouncilanindustrialhealthinstitutionwascommissionedtocarryoutairmeasure-ments(passivecollectors).Nothingunusualwasfound.However,in6airreadingsaltogetheronlytoluene,xylenesandethylbenzeneswereana-lysed.Basedonthevaluesmeasuredthedirectorofthedistricthealthofficegavetheall-clear.

Course of events:Thehealthproblemscontinuedtoincreaseduringthefollowingthreeyears.Inparticular,moreandmorechildreninthe“newclassrooms”inthiswingweresufferingsymptoms.Eventuallytheparentsof16childrenrefusedtoallowtheirchildrentohaveanyfurtherlessonsinthenewbuilding.Atthattimefiveteachersinallwerekeepingawrittenrecordoftheappearanceofthesymptoms,especiallyheadaches,butalsodifficultiesinswallowing,throatirritations,andreddeningoftheskin.Theclassesweremovedtootherroomsintheoldbuilding;teachers’andpupils’symptomsdisappearedcompletely.


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Investigations:31/2yearsafterthefirstindoorairreadingsweretakenfurtherinvestigationswerecommissioned.Firstly,afteraninspectionofthepropertyinquestion,aVOCairmeasurementwithactivatedcarbonandsilicagelcollectorsandaMVOCairmeasurementwithactivatedcarbontubeswerecarriedout(activesampling).Theseproducedindicationsofmicrobialdamage(evidenceofthemainindicators1-octen-3-ol,3-methyl-furananddimethyldisulphide).TheVOCairmeasurementproducedaverylowtotalTVOCconcentrationof230μg/m3,althoughat24.2μg/m3therewasanabnormalconcentrationof2-ethyl-1-hexanol,whichwastracedtothehydrolyticdisintegrationofthesoftenercompoundDEHP.Themeasure-mentwithsilicagelcollectiontubesrevealed109μg/m3of2.6-di-t-butylcresol.

Inallsevenmaterialsamplesofinsulationmaterial(polystyrene)andthedividinglayers(foilandpaperboard)weretakenoutofthefloorsandana-lysed.Infiveofthesevensamplesamassivemicrobialinfestationwasde-tected:thiswasparticularlysevereintheinsulatingmaterial,with850,000CFU/gofmould(aspergillusversicolor,penicilliumspp.,acremoniumsp.)and14,000,000CFU/gofbacteria(actinomycetesandbacillusspp.).Emis-sionsanalysesoftheflooringmaterials(PVCwithadhesiveandfiller)re-vealedabnormalemissionsof2-ethyl-1-hexanol.Whenthefloorwasopenedupitwasdiscoveredthattherewerehighlevelsofdampinthefloorundertheinsulationlayerandthattherewasanobvioustostrongmustyodourfromthefloor.

Thecauseofthehighmoisturelevelswasestablishedafterlengthyinves-tigations.Inthiscasetheywerenotcausedbystructuralfailings,butbythecleaningstaff,who,inthecourseofwashingthePVCfloorseachweekalwaystippedlargequantitiesofwaterontothemandlikedtosweepittothesideswith“squeegees”.Thewaterranintothegapsattheedges.

Recommendation:Thefloorswererenovatedonaccountofthefindings.Afterthatthesymptomssubsided.TheMVOCconcentrationsintheindoorairweremonitoredover12monthsinall,andonlyreachedbackgroundlevelsafteraboutayear.Asthesymptomshaddisappearedcompletelyaftertheremediation,despiteMVOCconcentrationsthatwerestillraisedatthestart,thisisaclearindicationthattheMVOCsdidnotdirectlycausethesymp-toms,butweresimplyanindicatorofthemicrobialdamage.


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PART E: Remediation guidelines and procedures

Inresponsetothecontaminationofbuildingswithhazardoussubstanceswhichbecameapparentsincethe1980s,the“pollutants”projectgroupoftheBauministerkonferenz[buildingministers’committee](Arbeitgemein-schaftderfürStädtebau,Bau-undWohnungswesenzuständigenMinisterder16Länder[ConferenceoftheLänderMinistersandSenatorsresponsibleforurbandevelopment,constructionandhousing]–ARGEBAU)devisedasetofguidelines.ThesewereintroducedascompulsorytechnicalbuildingregulationsinthemajorityoftheLänderandshouldthereforegenerallybeobservedduringremediationwork–inschoolsaselsewhere.Inaddi-tionARGEBAUpublishedthePAK-Hinweise[AdviceonPAHs](June2000),throughtheGermanInstituteforConstructionEngineering(DIBt),whichcanbeconsultedasnon-bindingrecommendationsforrenovatingwood-blockfloorslaidwithtar-basedadhesives.Theguidelinesandrecommenda-tionsreferredtoaresetoutinbriefbelow.

E-1 Asbestos

InMay1989the“RichtlinienfürdieBewertungundSanierungschwachge-bundenerAsbestprodukteinGebäuden”(Asbest-Richtlinien)[Guidelinesfortheevaluationandremediationoflooselyboundasbestosproductsinbuild-ings(AsbestosGuidelines)]werepublishedbytheARGEBAUprojectgroup.ArevisededitionwasissuedinJanuary1996andsubsequentlyintroducedastechnicalbuildingregulationsbytheconstructionauthorityinallLänder.

Theseguidelinesincludevariousevaluationfigures,accordingtothetypeofasbestosproduct,thestructuralcondition,theavailabilityoftheprod-uct,andthenatureandfrequencyoftheuseofthespacebythegroupofpeopleconcerned.Thesumoftheevaluationfiguresthenshowswhetherremediationisrequiredimmediately,inthemediumtermorinthelongterm.Insomecasesanindoorairmeasurementmayalsobenecessary.Oncompletionofremediationwork,tomonitoritssuccess,readingsoftheconcentrationofasbestosfibresintheindoorairshouldbecarriedoutinaccordancewiththeasbestosguidelines.Aftersuccessfulremediationtheasbestosconcentrationshouldbebelow500fibres/m3ofair.

Formostoftherelevantschoolbuildings,whichwereconstructedinthe1960sand1970s,thisevaluationmaybecompletedinthemeantimeusingtheasbestosguidelinesandappropriateremediationmeasurescarriedout.


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Theprinciplesofasbestosremediationaresummarisedinthefollowing(inanextractquotedfromtheasbestosguidelines):

1. “Remediationmeasuresmustbeplannedasaclosedconceptfromthebeginningoftheworktothedisposalofthewasteinaccordancewiththeapplicableregulations.

2. Onlythosefirmsshouldbecommissionedwhoarefamiliarwiththework,thehazardsarisingfromitandthenecessaryprotectivemeas-uresandwhohaveaccesstothenecessarytoolsandequipment.

3. Protectivemeasuresarenecessaryatalltimesduringtheremediation.”

Theplanningdepartmentsareresponsiblefortheremediationworks,andappointcompetentfirmsinaccordancewithPoint2.Iftheremediationhasnotyetbeencarriedout,itisessentialtoensurethatfibresarenotreleasedintotheindoorairthroughservicing,cleaningormaintenancework.

E-2 Polychlorinated biphenyls

AftertheproblemofcontaminationofbuildingswithPCBs–mainlyemittedbysealantscontainingPCBs,whichweremanufacturedanduseduntilthemid-1970s–cametolight(cf.SectionB-4),the“RichtliniefürdieBewertungundSanierungPCB-belasteterBaustoffeundBauteileinGebäu-den(PCB-Richtlinie)”[GuidelinesfortheevaluationandremediationofPCBcontaminatedmaterialsandcomponentsinbuildings(PCBguidelines)]weredevisedbythepollutantsprojectgroup.Theseguidelinescontainahealthevaluation,listremediationprocedures,evaluatetheirurgencyandgiveadviceontheup-to-datehealthandsafetyatworkregulationsaswellasanoverviewofrelevantlawsandordinancesrelatingtothedisposalofPCBcontaminatedproducts.InadditionrecommendationsfordeterminingthePCBsintheindoorairanalyticallyareprovided.TheguidelineswerepublishedinthereportsoftheGermanInstituteforConstructionEngineer-ing(DIBtNo.2,1995,pp.50–59).TheyhavebeenintroducedastechnicalbuildingregulationsbytheconstructionauthorityinmostLänder,evenifwithconsiderablealterationsinsomecases,andassuchshouldberegardedasbindinginconstructionlaw.

Itisaprerequisiteforproperremediationthatthemeasuresareplannedasaclosedconceptfromthebeginningoftheworktothedisposalofthewaste,andthatonlythosefirmsarecommissionedwhoarefamiliarwiththerelevantproblemsandpotentialhazardsandwhohaveaccesstothenecessarytoolsandequipment.Theremediationworkmustbecarriedoutwithaslittledustaspossible.Thefirststageofapermanentremediation


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isgenerallytheremovaloftheprimarysources.InsomecasesseparatingofftheareaofthebuildingcontaminatedwithPCBsfromunpollutedareaswithsolidstructures(dividingwalls,etc.)canalsobeasensibletemporarymeasure.Iftheindoorairconcentrationcannotbeloweredtothetargetvaluesspecifiedintheguidelinesimmediatelywiththesemeasures,there-mediationofsecondarysourcesisnecessaryaswell.Thesecondarysources,oftencoveringlargeareas(e.g.wallsandceilings),canberesurfaced,sepa-ratedofforevenremoved.

AfterremediationthePCBconcentrationintheindoorairshouldnotexceed0.3μg/m3ofairinthemiddleoftheyearifpossible.AsthePCBconcentrationinindoorairissubjecttoseasonalvariationsintemperature,asinglereadingisnotnecessarilyrepresentativeofthemid-yearvalue.VDIGuidelines4300part2containsinformationonasuitablemeasuringstrat-egyfordeterminingPCBsinindoorair.

E-3 Pentachlorophenol

In1996theARGEBAUpollutantsprojectgroupdevisedguidelinesfortheevaluationandremediationofPCP-contaminatedbuildingmaterialsandcomponentsinbuildings(thePCPGuidelines).TheGuidelineswerepub-lishedintheGermanInstituteforConstructionEngineeringreports(DIBtNo.2,1997,pp.6–15).ThePCPguidelineswerealsointroducedbythecon-structionauthoritiesinmostLänder.

Theflowchartshownintheguidelinesfordeterminingtheneedforreme-diationenvisagesthatitwillfirstbeestablishedwhetherwoodpreservativeshavebeenusedinconstructionmaterialsandcomponentsinthebuildinginquestion,orwhetherotherPCPsourcesshouldpossiblybesought.Ifwoodpreservativeshavebeenused,stagedtestswillbeneededonthedust,thetreatedwoodandtheindoorair,inaccordancewiththeaforemen-tionedflowchart.Theremediationdecisionshouldbededucedfromtheseonthebasisofthelimitvaluesstipulated.Possibleremediationmeasurescouldbe–ifviablefromaconstructionperspective–boththeremovalofthetreatedmaterialsandmeasuressuchasresurfacingandliningorseparatingofftheareawithtreatedcomponents.Theapplicablelegalre-quirementsforthedisposalofmaterialscontainingPCPsaresetoutintheguidelines.

Forprecautionaryhealthreasonsanindoorairvalueof<0.1μgPCP/m3ofindoorairshouldbethelong-termgoaltoaimatwhencarryingoutreme-diationwork.Thesuccessoftherenovationshouldbeverifiedbydetermin-


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ingthePCPcontentoftheindooraironthebasisoftheVDIGuidelines4300part4and4301part2.

InwoodpreservativesPCPwasusuallypresentwiththeinsecticidelindaneintheproportion10partsPCPto1partlindane(cf.SectionB-4).Accord-ingtotheevaluationoftheformerFederalInstituteforHealthProtectionofConsumersandVeterinaryMedicine(BgVV)adversehealtheffectscanveryprobablyberuledoutifanindoorairvalueof1μglindane/m3ofairismaintained.Indoorairvaluesof1μglindane/m3ofairandaboveareonlyreachedafterusingwoodpreservativesifthePCPpollutionisalsosignificantlyabove1μg/m3.ThePCPrelatedremediationthenrequiredalsoreducesthelindaneconcentrationfarenough.

E-4 Polycyclic aromatic hydrocarbons

In2000theARGEBAUpollutantsprojectgroupdevisedthe“HinweisefürdieBewertungundMaßnahmenzurVerminderungderPAK-Belastungdu-rchParkettbödenmitTeerklebstoffeninGebäuden(PAKHinweise)”[AdviceonevaluationandmeasurestoreducePAHcontaminationbywoodblockflooringwithtar-basedadhesivesinbuildings(PAHAdvice)].Thiswaspub-lishedinDIBtreportNo.4(2000)pp.114–123.

Thetar-basedadhesivesthatwereusedtogluewoodblockflooring,mainlyinthe1950sbutoccasionallyrightuptothe1970s,camebrieflytopublicattentioninthe1990s,afterraisedPAHconcentrationswerediscovered,forthemostpartinbuildingsformerlyoccupiedbyUSforcesinGermany.Theseweretracedbacktoadhesivesunderdilapidatedwoodblockfloors.Asthesemi-volatilePAHsaremainlytakenupbydust,theprojectgroupreachedthefollowingevaluation:“InthecaseofPAHcontaminationbytar-basedwoodflooradhesivesnoriskthresholdcanbeset,atwhichmeasuresareurgentlyneededtomeetplanninglegislation,overandaboveprecau-tionarymeasures.However,theadhocworkinggroupconsiderstheoccur-renceofcertainBaPconcentrationsundesirableonhygienegrounds…”

Benzo(a)pyrene(BaP)isregardedhereastheleadsubstanceforthegroupofpolycyclicaromatichydrocarbons.


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Theprojectgroupassumedthatingeneralrepairingthedamagedwoodfloorbyfillingthedefectivejointsandthensealingitissufficientandcom-pleteremovaloftheflooringandstrippingofforsealingoffthetar-basedadhesivesisonlynecessaryinseverecases.Theprojectgroupcametothefollowingconclusionforevaluatingthesuccessoftheremediation:

1. Inroomsusedforlongperiodsmeasurestoreduceexposureshouldbeintroducedifhousedustconcentrationsexceed100mgBaP/kgoffreshdust.

2. Inhomesorotherspaceswherebabiesorsmallchildrenregularlyspendseveralhoursadayoverafairlylongperiodandwhereexpo-suretodustistobeexpectedfromthetypeofuse,e.g.indaynurseriesorchildren’shomes,measurestoreduceexposureshouldbecarriedoutifhousedustconcentrationsexceed10mgBaP/kgoffreshdust.

Insomejustifiedcasesadditionalmedicalexaminationswererecommend-ed.ThePAHAdvicealsocontainsrecommendationsforhealthandsafetyatworkandfordisposalofwastecontainingPAHs.


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Appendix 1:

(Specimen) school hygiene plan

InaccordancewithArticle36para.1oftheProtectionagainstInfectionsAct(IfSG)schoolshaveadutytosetoutinternalproceduresforthemain-tenanceofinfectionhygieneinhygieneplans,inordertominimiseriskofinfection.Theplansshouldbedrawnupinthefollowingstages:

Analysisoftherisksofinfection

Evaluationoftherisks

Riskminimisation

Establishmentofmonitoringprocedures

Reviewofthehygieneplan

Documentationandtraining.

Thefollowingspecimenhygieneplanprovidessuggestionsfordevisingahygieneplanappropriatetothespecificcircumstancesoftheschoolcon-cerned.

Cleaning plan

Thecleaningplanshouldbeappropriatetothespecificcircumstances(hardwashablefloororcarpeting)oftheschoolconcernedinaccordancewiththeguidelinesinDIN77400“CleaningServices–SchoolBuildings–Clean-ingRequirements”forboththeschoolbuildingsandtheattachedsportsfacilities(seealsoA-2CleaningProcedures).

Thefollowingareasshouldbetakenintoaccount:

theentrancearea

thegroundfloortrafficareasandthestairstothefirstfloor

theremainingcorridorsandstaircases

classrooms

sanitaryareas,includingchangingrooms


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staffrooms,schooloffices,administrativeareas,officesandmeetingsrooms

storerooms

gymnasia

schoolmealskitchens,homeeconomicsroomsanddininghalls

Thoroughcleaningandmaintenanceshouldbecarriedoutinallareasoftheschoolatleastonceayear.Forroutinecleaningandtheannualinten-sivecleaningormaintenanceonlycleaningproductswhichposenohealthriskshouldbeused.Ifseveralcleaningproductsareused,acheckshouldbeundertakentomakesurethattheproductsdonotreactwithoneanotherandthatmixingthemdoesnotproducesubstanceshazardoustohealth.

“Cosycorners”inschoolsshouldbeavoidedifpossible.If,however,thesedoexist,itmustbeensuredthattheyarecleanedthoroughlytoanappro-priatestandardeveryweek.

Ventilation plan

Iftheschoolhasnomechanicalventilation,theclassroomsshouldbeaired,wherepossiblewithcross-ventilation,atleastaftereverylesson(45min-utes)andatthebeginningandendoftheschooldayduringterm-time.Theseniorstaffdecideswhoairstheclassroomaftereverylessonandhowitistobeaired.Inthelowerschooltheteacherwhoispresentshouldberesponsibleforthis.Intheupperschoolapupilrotacanbedrawnupforthisfunction.

AshumanshavenosensoryorganfordetectingtheCO2contentoftheair,

ventilation“trafficlights”canbeameansofvisualisingtheindoorairqual-ity.“Ventilationbehaviourtraining”canbecarriedoutinthisway.

Besidesregularmaintenance,existingindoorair-conditioningsystemsmustbeinspectedinaccordancewiththetechnicalregulations(VDI6022–Hy-gienerequirementsforair-conditioningsystemsandappliances).Aspecialinspectionisneededforthesystemcomponentswhichcontainmoistureintheformofwaterorcondensingwater,suchashumidifiersorheatex-changers.


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Noise reduction plan

Inschoolsthenoisefromthevicinity(road,railandairtraffic,industrialactivities),frompoorroomacousticsorfromthepupilsthemselvescanpresentaparticularproblem.TheWorkplacesOrdinanceprescribesanaveragemeasurementof55dB(A)forworkplaceswithpredominantlyintel-lectualactivity.

1. Noise from the surrounding area

Possiblemeasurestoreducetheeffectoftrafficnoisefrombusyroads:

Ventilationburstsinsteadofcontinuousventilationtoreducetheentryofnoisefromoutside

Installationofsoundproofwindows

2. Room acoustics

Speechintelligibilityisinfluencedmainlybythereverberationtime.Theacousticpropertiesofaroomareestablishedandevaluatedobjectivelybymeasuringthisreverberationtime.Thereverberationtimeinaclassroomshouldbeintheregionof0.5seconds.Byinstallingnoise-absorbentmateri-alinaroomthereverberationtimeisreducedandtheacousticsoptimised.

Simplemeasuresforimprovingroomacoustics:

Mufflingcontactofmoveablefurniturewiththefloor

Fittingfeltpadstochairandtablelegs

Oilingsqueakingdrawers

Installingnoise-absorbentfurnishings

Puttingupcurtainsatthewindows

Puttingupwallhangingsorcorktiles(e.g.pinboards)

Installingpanellingonwallsfromfloorleveluptoabout1.5metres(agreementfromeducationdepartmentorpublicworksdepartmentrequired)

Checkingceilingpanelsandinstallingnoise-absorbentceilingandwallpanelsifnecessary(agreementfromeducationdepartmentorpublicworksdepartmentrequired)

Usingquieterappliances(e.g.computerstationswithquietfans)


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Whenconstructingnewschoolbuildings,undertakingremediationorreno-vationorsubmittingcomplaintsthenewApril2004editionofDIN18041“Acousticqualityinsmalltomedium-sizedrooms”shouldbereferredto.

3. Organisational and educational recommendations

Puttinguprulesforhearingandlistening

Coveringthetopic„Noiseandtheeffectsofnoise”inclass(materialsforthisareavailablefreeofchargefromtheFederalCentreforHealthEducation(BZgA))

Usingvisualaidsfornoisereduction,e.g.Soundearor“noisetrafficlights”

Reducingclasssizes

Havingshortbreaksinthemiddleofdoublelessons

Conductingtraininginimprovedsocialbehaviour

Speakingslowlytoimprovespeechintelligibility

Ensuringeyecontactbetweenspeakerandlistener

Introducingsomephysicalexercisesifconcentrationflags

Voicetrainingforteacherstoprotectvocalcords

Stressmanagementprogrammesforteachers

Water hygiene

Inschoolsshowersinsportsfacilitiesandswimmingpoolscanposeapartic-ularproblemwithregardtolegionellacontamination.Topreventlegionel-lashowersthatarenotusedeverydayshouldberinsedthroughbyrunningthehotwaterdailyforaround5minutes(setthemaximumtemperaturetoatleast60oC).Limescaledepositsshouldberemovedfromtheshowerheadsattherequiredintervals.Thehealthagencyshouldbeconsultedaboutthenecessityforregularbacteriologicalinspectionsforlegionella.

Ifdrinking waterisusedinthepreparationoffoodordrinks,thewaterinthepipesshouldberunofffirst.

Thewaterinschool swimming pools shouldbetreatedinaccordancewiththeguidelinesinDIN19643.Itmustbeensuredthatthewaterinswimmingandbathingpoolsdoesnotposeanyhealthrisk.TheProtectionagainstInfectionsAct(Article37)providesthelegalbasisforthis:“Waterinswim-


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mingandbathingpoolsincommercialoperations,publicbathsandinothernotexclusivelyprivately-usedfacilitiesmustbesuchthatthereshouldbenoconcernthatanyharmtohumanhealth,especiallyfrompathogens,couldarisefromusingit”.

Inthisregardparticularattentionshouldbepaidtotheproperdisinfectionofthepoolwater.Thelimitvaluefortrihalogenmethanesof20μg/llaiddowninDIN19643mustbecompliedwith.Itmustbeensuredthatthestaffresponsibleforthepoolmachineryreceiveregularfurthertraininginthisfield.WithregardtothistherecommendationsoftheFederalEnviron-mentAgency/theBathingWaterCommission(seeBundesgesundheitsbl–Gesundheitsforsch–Gesundheitsschutz9,2006)andotherhygienerecom-mendationsshouldbetakenintoaccount.

Verruca infections in swimming pools and gymnasia /sportshalls

Besidesthegenerallywidespreadathlete’sfootinfectionstheoccurrenceofverrucasissometimesobservedinrelationtotheuseofswimmingpoolsandsportshalls.Verrucas/wartsandmolluscumcontagiosum(MC)areamongthemostcommonskincomplaintscausedbyviruses.Theycanoc-curatanyage,butwarts,especiallyMC,areparticularlycommonamongchildrenandadolescents.

Wartvirusesareusuallytransmittedbydirectorindirectcontact.Thiscanoccurthroughphysicalcontact,butalsothroughshareduseoftowels,sandalsetc.orthroughcontactwithflakesofskinonthefloor.Properlydisinfectedpoolwaterplaysnopartintransmission,asthepathogensarerenderedinactivebythechlorineinthewater.Itismorelikelythattransmissionarisesthroughdampseatingandfloorsroundthepoolandintheshowerandchangingroomcubicles,ifthesehavepreviouslybeenusedbyacarrierofverrucasorathlete’sfoot.Forthisreasonthesesurfacesaredisinfectedatleastonceadayatpublicbaths.

Measurestopreventtransmission(prophylaxis):

Teachers,especiallyP.E.andswimminginstructorsandpre-schoolstaffshouldbeinformedabouttransmissionroutes.

Parentsshouldalsobeinformedandshouldexplaintherelevantmeas-urestotheirchildren.Thesolesofchildren’sfeetandbetweentheirtoesshouldbeinspectedfrequently.

Beforeswimmingoneshouldwashthoroughlyfromheadtotoe,sothatthechlorineinthewaterdoesnotloseitsdisinfectanteffectbe-causeoforganicsubstances(sweat,oils).


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Sandalsshouldbeworninindoorpoolsandchangingrooms.

Shareduseoftowels,lotionsetc.byseveralpeopleshouldbeavoided.

Oneshouldnotwalkaboutbarefootincommunalfacilitieswithath-lete’sfootorverrucasthathavenotclearedup.

ThedoctoradministeringtreatmentshoulddecideonparticipationinswimmingorP.E.lessons,ifthisinvolvesphysicalcontact(possiblywithawrittencertificate).

Operatorsofswimmingpools,saunasandsportsfacilitiesshouldcarryoutorarrangeforthecleaningofpassageways,showersandchangingrooms,aswellasotherareasusedwithbarefeet,everyday,orwherenecessary,severaltimesdaily.

Attheendoftheworkingdayallsurfacesusedwithbarefeetinswim-mingpools,saunasandsportsfacilitiesshouldbecleanedusingadis-infectanttestedforitsvirucidalefficacy.Theproductshouldbeappliedwiththescrubandwipeprocedure.Sprayingaloneisnotsufficient,asskinflakesarenoteffectivelyremovedbythis.

Kitchens

Homeeconomicskitchensandschoolmealskitchensshouldbetreatedinthesamewaywithregardtothehygienerequirementstobemetinthem.PeoplesufferingfromaninfectionasdefinedbyArticle42oftheProtec-tionagainstInfectionsAct(IfSG)orfrominfectedcutsorskincomplaints,fromwhichthereisariskofpathogensbeingtransmittedviafood,maynotbeemployedinthekitchen.InaccordancewithArticle43oftheActthekitchenstaffshouldbeadvisedoftheworkingrestrictionsonceayear.

Thekitchenstaffshouldreceiveannualtraininginfoodhygiene.

Hand disinfectionbythoseworkinginkitchensisrequiredinthefollowingcases:

whenstartingwork

afterbreaks

aftereachvisittothelavatory

afterdirtyjobs

afterworkingwithcriticalrawgoods(e.g.rawmeat,poultry)

aftercoughingorsneezingintoone’shand,everytimeafterusingahandkerchief.


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Onlypreparationsthathavebeentestedandproveneffectivemaybeused.InthecaseofhanddisinfectantproductstheseshouldbechosenfromthedisinfectantslistissuedbytheDeutscheGesellschaftfürHygieneundMikro-biologie[Germanassociationforhygieneandmicrobiology].

Walldispensersshouldbeprovidedatwashbasinsforwashinganddisin-fectinghandsinthekitchenarea.Thecontentsofsoapanddisinfectantdis-pensersshouldbecheckedweekly.Beforerefillingthedispensersshouldbecleanedout.Liquidsoapsanddisinfectantsshouldbekeptintheiroriginalcontainers.

The procedure should be described:

Forexample:bothsidesofthehandstobecovered,togetherwithwrists,betweenthefingers,fingertips,cuticlesandthumbsandleftfor30secondsforthedisinfectanttowork.3to5mlofdisinfectant(acuppedhandfull)isneeded.

Thefloorsinthekitchenareashouldbecleaneddaily.Protectiveclothingshouldbeprovidedforparticulartasks(e.g.cleaningfloors).Thisprotectiveclothingshouldbechangeddaily,orasnecessary.

Surface disinfection is necessary:

whenworkingwithcriticalrawgoods(e.g.rawmeat,poultry)

afterfinishingworkonsurfaceswhereanimalproductshavebeenprepared.

Thedisinfectantisappliedtothesurfaceconcernedandspreadvigorouslywithaclothorsponge(scrubandwipedisinfection).Thedisinfectantmustbelefttotakeeffectbeforethesurfaceisusedagain.Surfacesthatcomeintocontactwithfoodshouldberinsedwithcleanwaterafterwards.

Topreventdeteriorationinfoodqualitythroughpestinfestationsfoodstuffsshouldbepackagedcorrectly(e.g.wrappeduporinbins)andthepackageslabelledwiththedateopened/dateprocessedandthecontents.


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Thefollowingin-housefoodinspectionsshouldbecarriedout:

goodsinspectiononarrivalforpackaging,bestbeforedates,varioustypesofdamagetogoods

dailytemperaturechecksonrefrigeratorsandfreezers(refrigerator<8oC,***freezer<-18oC)

weeklycheckonbestbeforedatesonfoods

inthecaseoffoodspreparedonsite,samplesshouldbestoredinfreez-ersfor96hours,separatedaccordingtoingredients.

Animal pests (parasites)

Inschoolsanimalpestscanbothattackhumansintheformofparasitessuchaslice,oroccuraspestsinclassrooms.

Outbreaksofheadliceinchildrenarearecurrentprobleminschools.Con-trollingoutbreaksofheadlicerequiresclosecooperationbetweenparents,schoolandhealthagency.Everycaseoflicemustbereportedbynameinwriting(byletter,faxore-mail)tothehealthagency,inaccordancewithArticle34oftheProtectionagainstInfectionsAct(IfSG).Apreciseplanofactionshouldbeputinplacefortheprocedureintheeventoftheoccur-renceoflice.

Example:

Ifachildisfoundtohaveheadlice,he/sheshould(afterconsulta-tionwiththeparents)besenthomeassoonaspossible,tocommencetreatment.ifthatisnotpossible,e.g.becausetheparentscannotbecontacted,thechildcanremaininthebuildinguntiltheendofhis/herusualsession.Closecontactduringthefollowinghoursshouldbeavoidedviadiscreetmeasures.

Withtheagreementoftherelevanthealthagencytheschoolinformsthepupils’parentsorguardiansoftheoutbreakoflice.Indoingsoanydiscriminationagainstthechildrenaffectedshouldbeavoided.

Theparentsareaskedtoexaminetheirchildrencarefully,andinthecaseofinfectiontocarryouttreatmentasdirectedbyadoctor.Atthesametimeexaminationandifnecessarytreatmentofallcontacts(families,friendsetc.)shouldtakeplace.


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IftreatmentoftheheadliceinfectionisundertakenimmediatelyandaccordingtotheencloseddirectionsusingaproductrecommendedbytheRobertKochInstitute(doctor’sprescriptionadvisable,alsoregardinginsuranceclaims),theaffectedchildrencan,dependingontheinfection,return to school straight away on the day after the initial treatment,iftheparentsconfirmthecorrectimplementationofthismeasurebywrittenreplyoradoctorcanruleoutthefurtherspreadofheadlicewithahighdegreeofcertainty.Thereplyshouldreachtheformteacherpromptly,withinthreedaysatthelatest.Itisessentialthattheparentsshouldbemadeawarethatasecond treatment is neces-sary within 8-10 days.

Ifnoreplyisreceivedwithinthisperiod,theestablishmentshouldwherepossibleattempttocontacttheparentsofthechildrenaffected(e.g.bytelephone).Ifnecessarytheyshouldbeaskedtoattendanotherexamination.Ifindividualparentsarenotwillingtocooperatedespitetheinformationreceived,alegalbasisforfurthersteps(meetingwithparents,examinationtoestablishfitnessforschool)isavailableintheeducationact.

TheProtectionagainstInfectionsActlaysdownthatthechildshouldbereadmittedtoschoolassoonas“intheopinionofadoctor”thereisnolongeranyriskofafurtherspreadoflice.TheActdoesnotdemandawrittencertificate.Inpracticeitcanbeassumedthatthedoctorinformsthepatientatthestartoftreatmentwhentherewillnolongerbeanyriskofcontagion.Adoctor’scertificateshouldbepresentedifthesamechildisre-infectedwithheadlicewithinfourweeks.

Inthecaseoffrequentoccurrencesofheadliceinoneschooladvicetoparentsandchecksonrepliesinparticularshouldbesteppedup.Thisappliesbothtorepliesfromtheaffectedchildrenandtorepliesfromchildrenwhohavehadcontact.Onlywhenalltheparentsofchildrenincontactsendrepliesorotherwiseconfirm,e.g.bytelephone,thattheirchildrenarefreeoflice,cantheschoolbesurethattheinforma-tionhasreachedallparentsandthatperhapspreviouslyunidentifiedcasesoflicearethereforebeingtreated.Theextentandtypeofadviceandtheproceduresshouldbelaiddowninconsultationwiththerel-evanthealthagency,which,dependingonthesituation,supportstheschoolincarryingoutthenecessarymeasures.

Kitchenareasareparticularlyatriskfromanimalpestinfestations.Kitchensshouldthereforebeinspectedregularlyforpest infestations.Intheeventofaninfestationpestcontrolmeasuresusingthemostup-to-datemethods


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shouldbecarriedoutbyaspecialistcompany.Particularcareshouldbetakensothatfooddoesnotcomeintocontactwithpestcontrolprepara-tionswhilethisistakingplace.

Foodwastemustbestoredinsealablecontainers,whichshouldbecleanedouteachtimetheyareemptied.Wastestoresmustbeabletobekeptcleanandfreeofanimalpests.Kitchenwindowsthatcanbeopenedtotheout-sideshouldbefittedwithinsectmesh.

Infectious diseases

Ahygieneriskfrombacteriaandvirusescanarisethroughtransmissionofinfectiousgermsfromonepersontoanotherviadropletorcontacttransmission.Thetransmissionofdiseasessuchasinfluenza,scarletfever(streptococcus pyogenes)andwhoopingcough(bordetella pertussis)ishowevernotaproblemspecifictoschools.TopreventthemtheencloseddirectionsfromtheRobertKochInstitute(e.g.HinweisefürÄrzte,LeitungenvonGemeinschaftseinrichtungenundGesundheitsämternzurWiederlassunginSchulenundsonstigenGemeinschaftseinrichtungen[Advicefordoctors,managementofcommunityfacilitiesandhealthagenciesonreadmittancetoschoolsandothercommunityfacilities],updatedversionofJuly2006,firstpublishedinBundesgesundheitsblatt44(2001):pp.830-843)shouldbeobservedandthechildreninstructedinhandhygieneandcoughetiquette.

First aid

Minorcutsshouldbecleanedwithtapwater(drinkingquality)beforedressing.

Thefirstaidershouldweardisposableglovesanddisinfecthis/herhandsbeforeandafteradministeringaid.Thenatureoftheinjuryshouldbeenteredintheaccidentbookinthefirstaidcabinet.Theparentsshouldbeinformedofthecause,natureandseverityoftheinjury.


127

Informationshouldbeprovidednearthefirstaidcabinetonwhothefirstaiderinthisareaisandwhichdoctortocall(providetelephonenumber)formoreseriousaccidents.Thisnoticeboardshouldalsodisplayinstruc-tionsonhowtodealwithcasesofpoisoning(provideemergencynumberforpoisons)andfires.

Checking first aid contents

Suitablefirstaidmaterialsinaccordancewiththepreventionofaccidentsregulation“GUVErsteHilfe0.3”arecontainedin:

largefirstaidchestequippedinaccordancewithDIN13169

smallfirstaidchestequippedinaccordancewithDIN13157.

Thefirstaidcabinetshouldadditionallybeequippedwithanalcohol-basedhanddisinfectantinasecurelysealedcontainer.Usedmaterials(e.g.dispos-ableglovesandplasters)shouldbereplacedpromptly,andregularchecksshouldbeundertakenonthecontentsofthefirstaidchests.Inparticular,theexpirydateonthehanddisinfectantshouldbechecked.

Treatment of contaminated surfaces

Surfacescontaminatedwithblood,vomitorotherpotentiallyinfectiousbodilyfluidsshouldbescrubbedwithadisinfectant-soakedclothandtheaffectedsurfacedisinfectedagainafterwards.Disposableglovesshouldbewornthroughout.

Procedures in the event of hygiene problems

If“classic”hygieneproblemsariseinaschoolorindoorcontaminationwithharmfulsubstancesissuspectedorestablished,thefirstactionistoinformtheschoolauthorities.Theywillinformtherelevanthealthagencyandtherelevantoccupationalhealthdepartment.Theseinstitutionswilltogetherputinplacethenecessarycrisismanagementmeasures.Thiscrisismanage-mentincludesinformingteachers,pupilsandparents.Ifitisnecessarytoundertakeenvironmentalhealthinspectionsorbuildingsurveysorcallinfurtherprofessionals,theseshouldbeorganisedbytheschoolauthoritiesafterconsultationwiththerelevanthealthagencyandtherelevantoccupa-tionalhealthdepartment.Theschoolauthoritiesareresponsibleforcheck-ingthenecessarycompetenceofthetradesmenbroughtin.Theteachingstaff,pupilsandparentsshouldbeinformedoftheresultsoftheseinvestiga-tions.


128


129

Symbols1.1.1-trichloroethane. 432-ethylhexanol. 42,.45α-pinene. 41β-pinene. 41δ-3-carene. 41

AAcetophenone. 43Acrolein. 43Acrylic.fabric. 44Actinomycetes. 69Acoustics. 93,.95Acoustic.ceiling.boards. 65Acoustic.ceiling.constructions. 67Acoustic.parameters. 94Acoustic.requirements. 93Acoustic.quality. 97Added.disinfectants. 23Adhesives. 83Ad.hoc.working.group. 13,.38,.46,.62Adipates. 55AgBB..(Ausschuss.zur.gesundheitlichen..Bewertung.von.Bauprodukten.–..Committee.for.the.Health.Evaluation.of.Building.Products). 75AgBB.evaluation.scheme. 30,.75Agents.in.wood.preservatives. 54Airborne.pollution.in.the..surrounding.area. 17Air.change.number. 24,.36Air-conditioning.scheme. 11Alcohols. 42,.81Aldehydes. 23,.42Aliphates. 40Alkenes. 40,.41Alkyd.resin.varnishes. 81Allergens. 68,.70

AOLG. 13Animal.allergens. 68Aromatics. 104,.105Aromatic.compounds. 41Asbestos. 63,.64Asbestosis. 65Asbestos.guidelines. 65Asbestos.product. 64Asbestos.spray. 64

BBacteria. 69Benzaldehyde. 42Benzene. 41Benzo(a)pyrene.(BaP). 59,.114Biological.substances. 68Biopersistence. 64,.67Biosoluble.SMF..insulation.materials. 67Blue.Angel. 81Blue.Angel.ecolabel. 29Bricks. 77Bromine. 26Brominated.compounds. 54Bronchial.tubes. 60Building.climate. 86Building.products. 30,.75,.76,.83Building.products.containing. 64Building.shell. 76Butanone. 43Butanonoxim. 40,.45Butyl.acetate. 43

CCarbon.dioxide.(CO

2). 25,.35

Carbon.monoxide.(CO). 35,.38Carcinogenicity.Index.(KI-Index). 66Carpeting. 21Case.studies. 99,.102

Appendix 2: Index


130

Changing.rooms. 22Chemical.wood.preservatives. 58Chemistry.laboratories. 32Cleaning.intervals. 19Cleaning.procedures. 19,.20Cleaning.products. 23Chloranisols. 43Chlorine.gas. 26Chloronaphthalene.in..prefabricated.school.buildings. 103Chloronaphthalene. 59,.103Classrooms. 17,.21Cloakrooms. 18Clophen.A50. 56Clophen.A60. 56CMR.substances. 33CO

2.concentrations. 36,.37

CO2.content.of.outside.air. 35

CO2.problem. 37

Coal.stoves. 59Coarser.particulate.matter. 60Complaints,.authorities..responsible.for. 29,.99Combustion.processes. 62Composite.wood.panels. 78Comprehensive.hygiene.plan. 23Concrete. 77Construction.Products.Act..(Bauproduktengesetz). 75Convection. 86Copiers. 34Corridors. 20Cosy.corners. 21Critical.fibres. 63Cross-ventilation. 25Cyclohexanone. 43

DDay.lighting. 24Demountables. 8Di-2(ethylhexyl)phthalate.(DEHP). .55Dibasic.dimethyl.esters. 107

Dichlofluanid. 58Diisobutyl.phthalate.(DiBP). 55Diisocyanates. 53Dimethylformamide. 44DIN.77400. 19Dining.rooms. 22Disinfection.by-products.(DBPs). 26Disinfectant.cleaning. 20Di-n-butyl-phthalate.(DBP). 55Di-iso-nonylphthalate.(DINP). 55Dust. 60

EEC.Construction.Products.Directive.75ELF.paints. 82EMICODE. 80Emulsion.paints. 82EN.13779. 37Energy.Conservation.Ordinance..(Energieeinsparverordnung,.EnEV).7,.11Esters. 43Ethanol. 42Ethyl.acetate. 43Evaluation.for.carbon.dioxide. 35Evaluations.of.VOC.concentrations. 45Evaporation. 86Extraction.systems. 24Extractor.hood. 33,.34

FFibre.dusts. 63Fine.particles. 34Fire.retardants. 34,.54First.aid.contents. 127Fixtures.and.fittings.for..indoor.areas. 84Floor.coverings. 84Floor.covering.adhesives. 82,.83Food.distribution.points. 22Formaldehyde.(CH

2O). 42,.52,.53

Formaldehyde.emissions. 53Formaldehyde-free. 78,.85


131

Free.ventilation. 92

Fundamental.hygiene.requirements.17

Fume.cupboards. 32

Furfural. 42

Furnishings. 18

GGas.cookers. 38

General.hygiene.requirements. 17

Glass.roofs. 90

Glasswool. 63,.65

Glutardialdehyde. 23

Glycols. 42

Glycol.ether. 42,.81

Glyoxal. 23

Guideline.value.I.(RW.I). 13,.46

Guideline.value.II.(RW.II). 13,.46

Gyms. 22

HHalogenated.organic.compounds. 43

Hand.disinfection. 122

Hazardous.Substances.Ordinance..

(Gefahrstoffverordnung). 8,.16

Head.lice. 70

Health.evaluations.of.particulate..

matter.in.indoor.environments. 62

Health.impact.of.dusts. 60

Health.problems.in.a.new.wing. 109

Heating. 18

Heat-retaining.components. 90

Home.Economics.practical.areas. 33

Hot.water.temperatures. 70

House.dust.mites. 68

Humidifiers. 70,.72

Hypochlorite.compounds. 26

IIll-fitting.windows. 11Indoor.Air.Hygiene.Commission..(Innenraumlufthygiene-.Kommission,.IRK). 13Indoor.acoustic.properties. 96Indoor.air.quality.in.schools. 7Indoor.contamination.with..dibasic.dimethyl.esters. 107Indoor.air.temperatures. 91Indoor.fountains. 72Inorganic.gases. 35Isobutanol. 42Isobutyl.acetate. 43Isocyanates. 79Isopropanol. 42

KKitchens. 22,.122

LLaboratories. 18,.32Laminate.floors. 76Laser.printers. 34,.62Legionella. 27,.70Light.conditions,.Lighting. 11Linoleum. 21,.42Linoleum.floor.coverings. 76Lime-sand.bricks. 77Limonene. 41Load-bearing.timber.components. 78Low-emission.floor.covering..adhesives. 83Low-formaldehyde. 78,.85Lung.cancer. 65

MMechanical.disturbance. 60Mechanical.ventilation. 92


132

Melamine-formaldehyde..adhesive.resin. 52Mesothelioma. 65Methyl.polysiloxanes. 43Micro-organisms. 68Mineral.fibres.from.suspended..ceiling.construction. 102Mineral.wool. 65Mineral.wool.products. 67Minimum.cleaning.frequencies. 20Minimum.requirements.for..cleaning.school.buildings. 19Minor.building.works. 28Moisture.damage. 69Mono-.and.dichloronaphthalenes. 59Mono-.to.trichloronaphthalenes. 43Mould. 68Mould.attack. 69Mould.damage. 68,.71Mould.growth.in.schools. 69,.44MVOCs. 44Mycotoxins. 71

NNaphthalene. 41Natural.air.exchange. 24Natural.ventilation. 92Need.for.remediation. 58,.68,.113Necessary.air.exchange. 25n-hexanal. 42Night.ventilation. 91Nitrogen.dioxide.(NO

2). 35,.38

Nitric.oxide.(NO). 38Nitrogen.oxides.(NO

x). 38,.33

Noise.insulation. 17Nonane. 40Non-specific.complaints. 45

OOctadecane. 40Odours. 29Odour.active.volatile.organic..compounds. 44

Odour.emissions. 30Odour.pollution.in.classrooms. 104Office.furniture. 85Olefins. 41Organophosphate.esters.(OPEs). 54OSB.panels. 78OVOCs. 44Ozone.(O

3). 34,.35,.39

PPAHs. 59PAH.concentrations. 114PAH.contamination.by.wood.-.block.floors. 114PAH.lead.substance. 59Particles. 34Particle.board. 59,.78Particle.size. 60Particulate.matter. 60Particulate.sources. 61PCBs. 54,.55,.112PCB.congeners. 55PCB.Guidelines. 56ff,.112ffPCB.remediation. 57p-dichlorobenzene. 43Pentachlorophenol. 57,.113Pettenkofer.number. 35Phenol-formaldehyde..adhesive.resins. 52Phosphoric.acid.esters. 54Phthalates. 55Pivot-hung.windows. 92PM.2.5. 63Polychlorinated.biphenyls..(PCBs). 54,.55,.112Polycyclic.aromatic.hydrocarbons.(PAHs). 54,.59,.114Polyurethane.glues. 53Porous.concrete.blocks. 77Preservatives. 82Preservatives.in.cans. 82Pressed.cork.products. 42Printers. 34


133

Procedural.model.for..indoor.guideline.values. 46Propanal. 43Propanol. 42Propiconazole. 58Pseudomonas.aeruginosa. 27Pulmonary.alveoli. 60

QQuaternary.ammonium.compounds.(QUATS). 23

RRadiation. 72Radon. 73Radon.risk.inside.buildings. 73Recirculated.air. 92Rendering.mortar. 77Renovations. 11,.29Reverberation.time. 95,.96Risk.of.lung.cancer. 73Rockwool. 65

SSanitary.facilities. 84Sawdust. 32School.furniture. 85School.offices. 22School.swimming.pools. 26Sealing.compounds. 40,.55Sealants.containing.PCBs. 112Sedimentary.particles. 60Semi-volatile.organic.compounds.(SVOCs). 54Silicate.paints. 82Siloxanes. 43SMF. 63,.65SMF.fibres.of.critical.size. 66Smoke.production. 32Softeners. 54,.55Solar.radiation. 89

Solvent-based.cleaning.products..on.wood.floors. 106Staffrooms. 22Stairwells. 20Structural.noise.insulation. 17Sun-protection.devices. 90Surface.disinfection. 20,.123Styrene. 41SVOCs. 31,.39,.54Synthetic.mineral.fibres. 63,.65

TTall.resins. 83Tall.oils. 83Tar-based.adhesives. 59Tar.products. 59Tebuconazole. 58Technology.lessons. 61Thermal.conduction. 86Thermal.radiation. 87Terpene.alcohols. 41Tetradecane. 40Texanol. 43Timber.cladding. 57Titanium.dioxide. 82Tobacco.smoke. 12,.59Toilets. 18Toluene. 41Toner.cartridge.changing. 34Toner.particles. 34Total.PCBs. 56Total.volatile.organic.compounds. 47Transparent.window.area. 89Treatment.of..swimming.pool.water. 27Trihalogen.methanes. 26TSPs. 60Tuberculosis.bacteria. 69TVOCs. 39TVOC.evaluation. 47TVOC.values. 48


134

UUltra-fine.particles. 34Ultra-fine.particulate.matter. 34,.60Urea-formaldehyde-resins..adhesives. 52,.79

VVarnishing.parquet.floors. 81Ventilating. 21,.24Ventilation.requirements..for.workshops. 32Ventilation.technology. 92Ventilation.through.windows. 24,.92VOC.emissions. 29,.30Volatile.organic.compounds..(VOCs).. 31,.34,.39,.40,.47VVOCs. 39

WWall.paints. 82Wart/verruca.infections. 27Washbasins. 22,.23Washing. 19Washrooms. 22Windowless.rooms. 12Working.Group.of.the..Supreme.Health.Authorities.of..the.Federal.States. 13,.35,.46Workshops. 32Wood. 57,.78Wood-based.materials. 52,.59Wood.glazes. 81Wood.preservatives. 52,.59Woodworking.machinery. 32


135


136


Tabe

lle 6

: Hyg

ieni

sche

Bew

ertu

ng v

on T

VOC-

Wer

ten

und

dara

us r

esul

tier

ende

Em

pfeh

lung

en fü

r M

aßna

hmen

(Um

wel

tbun

desa

mt

2007

)

Stuf

eKo

nzen

trat

ions

bere

ich

[mg/

m3 ]

Hygi

enis

che

Bew

ertu

ngzu

klä

rend

e Fr

agen

Empf

ehlu

ngen

1≤

0,3

mg/m

3

Hyg

ien

isch

un

bed

enk

lich

. In

der

Reg

el k

ein

e Bes

chw

erden

.

Lieg

en R

ich

twer

tüber

sc

hre

itun

gen

vor?

Kei

ne

wei

tere

n M

aßn

ahm

en.

2>

0, 3

–1 m

g/m

3

Hyg

ien

isch

noch

un

be

den

klic

h, s

owei

t ke

ine

Ric

htw

ertü

ber

sch

rei

tun

gen

fü

r Ei

nze

lsto

ffe

bzw

. Sto

ffgru

ppen

vo

rlie

gen

.

In E

inze

lfäl

len

Be

sch

wer

den

oder

Ge

ruch

swah

rneh

mun

gen

, z.

B. n

ach

kle

iner

en

Ren

ovie

run

gsm

aßn

ah

men

oder

Neu

möb

lie

run

gen

in

den

let

zten

W

och

en.

Lieg

en R

ich

twer

tüber

sc

hre

itun

gen

vor

? Li

egen

auff

ällige

Ref

eren

zw

ertü

ber

sch

reit

un

gen

vo

r?

Sin

d d

ie r

aum

klim

ati

sch

en B

edin

gun

gen

(L

uft

wec

hse

l, Te

m

per

atur,

Luft

feuch

te)

ein

wan

dfr

ei?

Ausr

eich

end L

üft

en b

eson

der

s n

ach

Ren

ovie

ru

ngsa

rbei

ten

.

VO

CQ

uel

len

erm

itte

ln (z.

B. B

egeh

un

g

des

Rau

mes

).

Ver

wen

dun

g v

on

Putz

un

d R

ein

igun

gsm

itte

ln

über

prü

fen

.

Nac

hm

essu

ngen

zur

Kon

trolle

von

Ric

htw

ert

über

sch

reit

un

gen

un

ter

Nutz

un

gsb

edin

gun

gen

(s

. Kap

. 9).

3>

1–3

mg/m

3

Hyg

ien

isch

au

ffäl

lig.

Nu

tzu

ng b

ei R

äum

en,

die

reg

elm

äßig

gen

utz

t w

erden

, nu

r bef

rist

et

akze

pta

bel

(<

12

Mon

ate)

.

Inn

erh

alb v

on

ca.

6

Mon

aten

sollte

n T

VO

C

Kon

zen

trat

ion

deu

tlic

h

un

ter

den

an

fan

gs

gem

esse

nen

TV

OC

W

ert

abges

enkt

w

erden

.

Fälle

mit

Bes

chw

erden

oder

Ger

uch

swah

rn

ehm

un

gen

, z. B

. nac

h

grö

ßere

n R

enov

ie

run

gsa

rbei

ten

.

Lieg

en R

ich

twer

tüber

sc

hre

itun

gen

vor?

Lieg

en a

uff

ällige

Ref

ere

nzw

ertü

ber

sch

reit

un

gen

vor?

Sin

d d

ie r

aum

klim

ati

sch

en B

edin

gun

gen

(L

uft

wec

hse

l, Te

m

per

atur,

Luft

feuch

te)

ein

wan

dfr

ei?

Ric

htw

ertü

ber

sch

reit

un

gen

um

geh

end d

urc

h

Nac

hm

essu

ng u

nte

r N

utz

un

gsb

edin

gun

gen

ko

ntr

ollie

ren

un

d b

ei d

er B

ewer

tun

g d

ie H

in

wei

se in

Kap

. 4 b

erück

sich

tigen

.

Auff

ällige

Ref

eren

zwer

tüber

sch

reit

un

gen

auf

ges

un

dh

eitl

ich

e R

elev

anz

prü

fen

.

In jed

em F

all: Q

uel

len

such

e durc

hfü

hre

n u

nd

Lüft

un

gsv

erh

alte

n ü

ber

prü

fen

: in

ten

siv

lüft

en

un

d g

gf. N

utz

un

gs

un

d L

üft

un

gsb

edin

gun

gen

fe

stle

gen

.

Kon

trollm

essu

ng b

zw. N

ach

mes

sun

g n

ach

ca

. 1 M

on

at e

mpfo

hle

n (u

nte

r N

utz

un

gsb

edin

gun

gen

).

Lieg

t n

ach

12

Mon

aten

tro

tz d

er b

esch

rieb

enen

Bem

üh

un

gen

die

TV

OC

Kon

zen

trat

ion

wei

terh

in

über

1 m

g/m

3 , s

o s

ind a

däq

uat

e Sa

nie

run

gsm

aß

nah

men

in

die

wei

tere

Pla

nun

g a

ufz

un

ehm

en.

4>

3–10

mg/m

3

Hyg

ien

isch

bed

enkl

ich

Nu

tzu

ng b

ei R

äum

en,

die

reg

elm

äßig

gen

utz

t w

erden

, nu

r bef

rist

et

akze

pta

bel

(<

1 M

on

at).

Die

TV

OC

Kon

zen

tra

tion

sollte

in

ner

hal

b

ein

es M

on

ats

un

ter

3 m

g/m

3 ab

ges

enkt

w

erden

.

Fälle

mit

Häu

fun

g v

on

Bes

chw

erden

oder

G

eru

chsw

ahrn

ehm

un

gen

, z. B

. nac

h g

röße

re

n R

enov

ieru

ngsa

rbei

ten

.

Lieg

en R

ich

twer

tüber

sc

hre

itun

gen

vor?

Lieg

en a

uff

ällige

Ref

ere

nzw

ertü

ber

sch

reit

un

gen

vor?

Sin

d d

ie r

aum

klim

ati

sch

en B

edin

gun

gen

(L

uft

wec

hse

l, Te

m

per

atur,

Luft

feuch

te)

ein

wan

dfr

ei?

Ric

htw

ertü

ber

sch

reit

un

gen

um

geh

end d

urc

h

Nac

hm

essu

ng u

nte

r N

utz

un

gsb

edin

gun

gen

ko

ntr

ollie

ren

un

d b

ei d

er B

ewer

tun

g d

ie H

in

wei

se in

Kap

. 4 b

erück

sich

tigen

.

Auff

ällige

Ref

eren

zwer

tüber

sch

reit

un

gen

auf

ges

un

dh

eitl

ich

e R

elev

anz

prü

fen

. Tox

ikolo

gis

che

Bew

ertu

ng v

on

Ein

zels

toff

en o

der

Sto

ffgru

ppen

er

ford

erlich

.

In jed

em F

all: Q

uel

len

such

e durc

hfü

hre

n u

nd

inte

nsi

v lü

ften

un

d g

gf. N

utz

un

gs

un

d L

üf

tun

gsb

edin

gun

gen

fes

tleg

en u

nd g

eeig

net

e M

inim

ieru

ngsm

aßn

ahm

en v

eran

lass

en. E

in

ggf. n

otw

endig

er A

ufe

nth

alt

ist

nur

mit

zei

tlich

er B

esch

rän

kun

g p

ro T

ag ü

ber

ein

en v

om

G

esun

dh

eits

amt

vorz

ugeb

enden

max

imal

en

Zei

trau

m (pro

Tag

stu

nden

wei

se/z

eitl

ich

bef

rist

et) to

lera

bel

.

Kon

trollm

essu

ng b

zw. N

ach

mes

sun

g n

ach

ca

. 1 M

on

at e

mpfo

hle

n (u

nte

r N

utz

un

gsb

edin

gun

gen

).

Lieg

t n

ach

1 M

on

at t

rotz

der

bes

chri

eben

en

Bem

üh

un

gen

die

TV

OC

Kon

zen

trat

ion

wei

ter

h

in ü

ber

3 m

g/m

3 , s

o s

ind a

däq

uat

e Sa

nie

run

gs

maß

nah

men

in

die

wei

tere

Pla

nun

g a

ufz

un

eh

men

.

5>

10–2

5 m

g/m

3

Hyg

ien

isch

in

akze

p

tabel

.

Rau

mn

utz

un

g m

ög

lich

st v

erm

eiden

. Ein

A

ufe

nth

alt

ist

alle

nfa

lls

pro

Tag

stu

nden

wei

se

/zei

tlic

h b

efri

stet

zu

läss

ig.

Bei

Wer

ten

ober

hal

b

von

25

mg/m

3 is

t ei

ne

Rau

mn

utz

un

g z

u

un

terl

asse

n.

Die

TV

OC

Kon

zen

tra

tion

sollte

in

ner

hal

b

ein

es M

on

ats

un

ter

3 m

g/m

3 ab

ges

enkt

w

erden

.

In d

er R

egel

Bes

chw

er

den

un

d G

eru

chsw

ahr

neh

mu

ngen

z. B

. nac

h

Feh

lan

wen

du

ngen

, U

nfä

llen

.

Lieg

en a

uff

ällige

R

efer

enzw

ertü

ber

sc

hre

itun

gen

vor?

Lieg

en R

ich

twer

tüber

sc

hre

itun

gen

vor?

Sin

d d

ie r

aum

klim

ati

sch

en B

edin

gun

gen

(L

uft

wec

hse

l, Te

m

per

atur,

Luft

feuch

te)

ein

wan

dfr

ei?

Ric

htw

ertü

ber

sch

reit

un

gen

um

geh

end d

urc

h

Nac

hm

essu

ng u

nte

r N

utz

un

gsb

edin

gun

gen

ko

ntr

ollie

ren

un

d b

ei d

er B

ewer

tun

g d

ie H

in

wei

se in

Kap

. 4 b

erück

sich

tigen

.

Auff

ällige

Ref

eren

zwer

tüber

sch

reit

un

gen

auf

ges

un

dh

eitl

ich

e R

elev

anz

prü

fen

. Tox

ikolo

gis

che

Bew

ertu

ng v

on

Ein

zels

toff

en o

der

Sto

ffgru

ppen

er

ford

erlich

.

In jed

em F

all: Q

uel

len

such

e durc

hfü

hre

n u

nd

inte

nsi

v lü

ften

un

d N

utz

un

gs

un

d L

üft

un

gs

bed

ingun

gen

fes

tleg

en u

nd g

eeig

net

e M

ini

mie

run

gsm

aßn

ahm

en v

eran

lass

en. E

in g

gf.

notw

endig

er A

ufe

nth

alt

ist

nur

mit

zei

tlic

her

Bes

chrä

nku

ng p

ro T

ag ü

ber

ein

en v

om

G

esun

dh

eits

amt

vorz

ugeb

enden

max

imal

en

Zei

trau

m (pro

Tag

stu

nden

wei

se/z

eitl

ich

bef

rist

et) to

lera

bel

.

Kon

trollm

essu

ng b

zw. N

ach

mes

sun

g in

ner

hal

b

von

1 M

on

at (un

ter

Nutz

un

gsb

edin

gun

gen

).

Wir

d d

urc

h M

inim

ieru

ngsm

aßn

ahm

en

10 m

g/m

3 im

bet

rach

tete

n Z

eitr

aum

zw

ar

un

ters

chri

tten

, ein

e K

on

zen

trat

ion

von

3 m

g/m

3 al

lerd

ings

wei

terh

in ü

ber

sch

ritt

en, g

elte

n

die

Maß

nah

men

empfe

hlu

ngen

wie

un

ter

St

ufe

4. L

iegt

nac

h 1

Mon

at t

rotz

der

bes

chri

ebe

nen

Bem

üh

un

gen

die

TV

OC

Kon

zen

trat

ion

wei

te

rhin

über

10

mg/m

3 , s

o s

ollte

die

Rau

mn

utz

un

g

un

ter

ble

iben

un

d e

s si

nd a

däq

uat

e Sa

nie

run

gs

maß

nah

men

zu v

eran

lass

en.

08.115_UBA_Schule_Ausklapper_03_RZ.indd 1 26.11.2008 11:14:13 Uhr

| UMWELT & GESUNDHEIT |

GUIDELINES FOR INDOOR AIR HYGIENE IN SCHOOL BUILDINGS

Guid

elin

es fo

r In

door

Air

Hyg

enie

in S

choo

l Bui

ldin

gs

Edi

tion

200

8

Contact: Federal Environment AgencyPostfach 140606813 Dessau-RoßlauInternet: www.umweltbundesamt.de E-mail: [email protected] Printed on 100% recycled paper