Isocyanatesat work

AN ACTION PROGRAMME FROM THE SWEDISH TRADE UNION CONFEDERATION

Programme GroupThe environmental and working life committee of the Swedish TradeUnion Confederation (LO) decided, following a request from theMetal Workers’ Union, to appoint a programme group with the assign-ment of drafting a common union action programme for the area ofisocyanates and similar plastics. The programme group has worked inclose collaboration with the LO working group for Chemicals.

The LO Chemicals Group has the following permanent members:

Kjell Johansson Building workers’ Union

Sigurd Holmqvist Graphic Trades Union

Stefan Eriksson Retail Employees’ Union

Ulf Lavenius Industry Union (programme group)

Pia Bellhagen Council Workers’ Union

Mats Hansson Farm Workers’ Union

Lars-Erik Folkesson Metal Workers’ Union

(programme group)

Stefan Wiberg Painters’ Union (programme group)

Mikael Jansson Paper Industry Workers’ Union

Göran Hansson SEKO

Bo-Ingemar Johansson Forestry and Woodworkers’ Union

(programme group)

Sven Bergström LO, chairman (programme group)

Sven Nyberg LO, secretary

Bo Tengberg LO

During the latter part of the programme group work, Ulf Lavenius wasreplaced by Kenneth Strandh. In addition, Rolf Ählberg, MetalWorkers’ Union, was a member of the programme group until he re-tired.

The attached plan of action was approved by the LO executivecouncil on 22 November 1999.

ISOCYANATESAT WORK

The Swedish Trade Union ConfederationAction Programme for the area of isocyanates and similar plastics.

Isocyanates at work – Isocyanater på jobbet

Swedish Trade Union Confederation – SE 105 53 Stockholm, Sweden

Translation: Stockholms Språkcentrum

Tryck: EO Print AB, Stockholm

LO 2000.07Art.nr 566-1709-7

ContentsPage

Some personal cases ..................................................................... 61. Moulding of mineral wool...................................................... 62. Sub-contract manufacture of car components........................ 63. Car repairs.............................................................................. 7

Where are isocyanates found?....................................................... 8When material or surfaces containing PUR are heated .............. 9When binders are heated ...........................................................11Examples of activities/industries where isocyanates occur .........13

How am I affected..........................................................................14Over-sensitivity ..........................................................................14Irritation.....................................................................................15Sensitising ..................................................................................15Cancer .......................................................................................16If you are already affected..........................................................16

Risks and Exposure........................................................................18Manufacture of PUR..................................................................18The Finished PUR products .......................................................19Applying heat to PUR................................................................21Additives....................................................................................22Further research is needed .........................................................23

Measurement of Isocyanates.........................................................25Exposure measurement of isocyanates .......................................27Biological sampling ....................................................................28

Training ...........................................................................................30Personal Protective Equipment......................................................32

Breathing protection ..................................................................32Protective gloves, protective clothing and eye protection ..........33

Manufacturers and Suppliers .........................................................35Regulation and Supervision ...........................................................38Measures at the Workplace...........................................................41Union Check List ............................................................................44Read More ......................................................................................46

LO demands – see the inside back cover

Preface

The working life of an individual and his work itself are in a state ofconstant change. Technical progress gives new products, productionmethods and forms of organisation, which can entail new risks. Oneof the main tasks of the trade union movement is to track develop-ments with great attention, with the aim of preventing damage to theenvironment and personal injury.

Problems associated with isocyanates in the plastics manufacturingindustry were discovered as far back as 1951. Since then, the use ofisocyanates has grown considerably and applications are found in justabout all fields of work these days.

New knowledge shows that symptoms such as asthma and allergiescan be explained by exposure to isocyanates at the workplace.Deficient methods of measurement have concealed the correlationbetween poor health and work until the present time.

Little knowledge exists about what happens when products contain-ing plastics are heated, and incomplete product information meansthat many workers are now exposed to isocyanates in their workingenvironments. The lack of knowledge means that many are affected,and have to leave the workforce before their time. Many do this with-out acknowledgement that one of the reasons could be exposure atwork. For this reason, greater awareness and preventive measures areneeded in Sweden, the EU and internationally.

One great unfairness is found in the conditions of working life of theindividual. Less than half of LO members (the blue-collar workforce)are able to continue working until retirement age. In the age group of55 – 59 years, the risk of premature retirement is 5 times higher forblue-collar workers than for white-collar staff. Female LO membersrun the greatest risk of being affected.

The unfairness of these working conditions must be corrected. Betterhealth for LO members is now on the agenda, through extension ofsystematic environmental work. Knowledge at local levels in com-panies must be improved through education and better adherence to

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rules.When necessary, there must be access to external expert help forqualified measurements etc.

Central knowledge acquisition is needed to support good preventiveenvironmental work at the local level.This requires not only sufficientresources for research and supervision, but also fair industrial injurystatistics. It is also necessary that correlations between poor health andenvironmental factors are not suppressed, and that the responsibleauthorities are informed.

Wanja Lundby-Wedin

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Some Personal cases

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1. Moulding of mineral woolLennart had not worked with making various insulationproducts for long before he began to experience problems.His work consisted of pressing various forms of mineralwool at high temperature. After doing this job for oneyear, Lennart fainted on his way home after a night shift.His breathing passages had contracted so much thatLennart could not get air. At the hospital, they foundhyperactivity in his lungs. They did tests for several years,but never found the reason for the problems.

Thanks to the help of the regional safety representative,who also works as an insurance advisor, Lennart was final-ly able to get a clear picture of what caused the problems.The explanation could be determined after a number ofarticles appeared in the press about the way that isocya-nates could be released when mineral wool is heated.After measurements were done at Lennart’s workplace,the Social Insurance Office approved the industrial injury,and acknowledged that the problems were related to iso-cyanate exposure. Lennart has managed to find a job thesedays, where he does not have to put up with exposure tostrong odors or chemicals.

2. Sub-contract manufacture of car componentsLola’s work was making interior trim components for cars.Part of the job involved bonding plastic components to-gether. Hot air guns were used to make the adhesive,which contained isocyanates, to harden quickly. Lola wasaffected by various kinds of oversensitivity. In addition toproblems with her breathing passages, her skin becamebright red, and she suffered from sensitivity in her face.Several of her colleagues were also affected by variouskinds of allergic reactions, tiredness and asthma.

Lola has not managed to get her problems approved as an

Lennart Nilsson.

Lola Ottosson.

industrial injury. She has had problems in getting supportfor the view that her over-sensitivity could be due to expo-sure to isocyanates at work. The presence of isocyanates ather workplace is well known and documented, however.

3. Car repairsGöran, aged 36, has worked as a car body repairman for18–20 years. His problems became worse during the lastsix or seven years. The days often started with his nosebleeding. Then he had nose bleeds several times a day. Inaddition, he had difficulties in swallowing and breathing.He was very tired when he got home in the evenings andfell asleep early. One of Göran’s colleagues has been affect-ed with the same type of symptoms, with nose bleeds andproblems with breathing.

The company doctor sent Göran to the Industrial andEnvironmental Medicine Clinic. The chief doctor studiedthe product information brochures for several of thepaints, which Göran used. His conclusion was that sincethe product brochures did not specify the inclusion ofisocyanates, that could not be the reason for Göran’s symp-toms. But by referring to Göran’s health and general work-ing conditions, he specified better ventilation and the useof a compressed air mask at work.

Thanks to the union, Göran managed to get his problemsapproved as being work-related. The correlation was notrelated to isocyanate exposure, but to welding work ingeneral. Göran has now been unemployed for a long time.

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Göran Falk.

Where Isocyanatesare found

Isocyanates are a group of chemicals, which have been used in indus-try for about 50 years, mainly in the manufacture of polyurethaneplastics (PUR). Use of PUR has widened considerably as time has pas-sed. From the beginning, it was mainly used for mattresses and foamrubber, but is now used in many different fields. The reason is thatPUR offers several technical advantages. The properties of materialscan be modified thanks to various additives. PUR is found in foamplastics, thermoplastics, fibres and adhesives and also in paints, foilsand insulation materials.

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The widened use of PUR in various products means that many work-ers do not understand the risk of being exposed. Without knowledge

Application of car window glue.

of the risks, you can also have difficulties in seeing the correlation be-tween poor health and working conditions.

Isocyanates occur as more or less viscous fluids and in powder form.There are a large number of different isocyanates. The following threetypes comprise more than 90 percent of all isocyanates made indus-trially:

TDI, toluene diisocyanate

MDI, methylene bisphenylisocyanate

HDI, hexamethylene diisocyanate

When material or surfaces containing PUR are heatedThe risk of exposure to isocyanates does not only occur when hand-ling chemical products, which contain isocyanates. Developments inmeasurement methods in recent years have shown that many peoplewho heat material containing PUR are also exposed to high levelsof isocyanates and other substances. This is common when surfacestreated with paints or varnishes containing PUR are heated. For exam-ple, various types of copper products are varnished, such as waterpipes and electrical wiring, to retain their gloss.

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Soldering of a PUR lacquer circuit board.

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Welding in PUR insulated steel pipe.

Grinding in PUR painted car.

Another example is PUR varnished floors, which are commonly foundin garages and workshops. When flame cutting or other work makesred-hot sparks fly and hit the floor, the varnish suffers from chemicalbreakdown. Measurements have shown that this can cause severeexposure, far above the relevant hygienic limits.

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When binders are heated

Example: When 1 gramme of PUR is heated to about 250°C, the break-down products must be diluted in 5000 m3 of air to preventthe break-down products from exceeding the hygienic limit.

High temperature treatment of mineral wool.

Even if isocyanates or PUR are not initially found in a product fromthe beginning, they can be released during heating. In recent years,it has been found that new domestic ovens give off isocyanates. Thereason is that the insulation around the oven has been treated witha binder, not to give off dust. The binder contains three chemicals,formaldehyde, phenol and urea. These components can form methylisocyanate (MIC) and isocyanic acid (ICA) if the material is heated.The temperature needed to form MIC is about 150°C. Toxicity is veryhigh. The accident in Bhopal in India in 1984 is often used as an

example of this in the literature. 2.000 people died there because ofthe high toxicity, and 170.000 were injured when MIC leaked fromthe factory. Other effects reported were reproductive dysfunction andspontaneous abortions.

The corresponding problem is found in the foundry industry, where asimilar binder is used to hold casting cores and shell sand together.Another product, which contains equivalent components, is Bakelite.Similar products are commonly found in electronic equipment, suchas circuit cards. Exposure is worsened if the cards are PUR varnished.The cores of grinding and cutting disks often consist of materials simi-lar to Bakelite.

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Examples of activities/industries where isocyanates occur

Activity/industry Source On heating

Motor industry,ships, aircraft &trains

Building

Fire extinguishing

Electrical &electronics

Paint industry

Foundry

Graphic trades

Foodstuffs

Painting & varnishing

Plastics industry

Tunnelling

Wood and furniture

Engineering

White goods industry

Medical care

filler, paint, seal-ants, windscreenassembly, bonding,composites

sealing, bonding,painting, caulking,floor and wallcoverings

packaging,adhesives, casting

manufacture

cold-box

printing inks,lamination

can varnishes

car & industrialpainting

manufacture offoam mattresses,car interior fittings

Sealants

adhesives,varnish, upholsterypadding, painting

adhesives,elastomers, paint,insulation, fixatives

manufacture PURinsulation, painting

bandages,castings, fillings,equipment

cutting, welding, grinding,windscreen removal, removal ofunderseal

mineral wool, mat welding, copperpies, paint removal, district heatingpipes

mineral wool, polyurethane infurniture and interior fittings

circuit cards, optical fibres,varnished wires, cable insulation,Bakelite

repairs

hot-box, casting cores and shellsand

conveyors, repairs packagingmaterials

removal of paints & varnishes withheat

self-ignition occurs

removal of paints & varnishes withhot air gun

repairs and removal ofpolyurethane materials with heat

repairs

How am I Affected?

Over-sensitivityThe most critical effect of isocyanate exposure is that you can developisocyanate asthma. Excess sensitivity can develop in parallel with it,which means that you can not go near your old workplace. After sen-sitisation, many people also are adversely affected by other odours,such as perfume, car exhausts or tobacco smoke. This type of symp-tom means that people often can not continue to participate in theworkforce.

Another serious effect is reduced lung function, which the affect-ed person frequently does not discover until it is too late. Not in-frequently, the problem is experienced as a considerable loss of fitness.Various types of skin reactions spread across various parts of the body,even when no direct skin exposure has occurred. There are frequentreports that people have been affected by nosebleeds in conjunctionwith “hot work”.

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Figure 1: Isocyanate exposure can take place in several ways. In addition tobreathing, which is the main exposure route, isocyanates can also enter the body

in other ways. The importance of skin exposure for asthma symptoms is discussedin the literature. Knowledge of the importance of absorption via stomach and

intestines is currently limited. Another route could be via various kinds of implants.

Eyes

Breathing passages

➞

➞

Stomach/intestine➞

Skin➞

Other➞

The greatest threats to health are absorption through breathing gasesand particles. A further form, which is frequently distinguished, isaerosols (fine drops of fluid) which are formed in spray painting etc.Isocyanates also affect eyes and can be absorbed via the skin. Know-ledge about absorption via stomach and intestines is still limited.

The serious effects of isocyanates on health have justified very lowhygienic limits. The average concentration in air in the breathing zoneduring a working day must not exceed 0.005 ppm (ppm = parts permillion). This converts to no more than 0,00004 g TDI in each cubicmetre of air. The peak exposure limit for a 5-minute period must notexceed 0,01 ppm.

Research in recent years has shown that it is possible to develop asth-ma from isolated, very brief but concentrated exposure peaks. All iso-cyanates are marked as sensitising in the limit value list. At present,only TDI is marked as carcinogenous.

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The odour threshold for the most common isocyanates isaround 0.4 ppm, i.e. considerably above the current hygien-ic limits. The absence of odour at a workplace is thus noguarantee whatsoever that you have not been subjected toexposure which far exceeds the current limits.

The scientific literature on the health effects of isocyanates distin-guishes between irritating, sensitising and cancer.

IrritationIsocyanates are hazardous to your lungs and irritate eyes and skin.Breathing vapours and mist can cause pain and “pins and needles” sen-sations in air passages, coughing, nausea and vomiting. Influenza-likeproblems can occur, with symptoms such as a runny or stuffed-upnose, sore throat, and chest pains. Other symptoms are coughing,fever, shivering, joint pains, muscle pains and headaches. Asthma-likeproblems of wheezing, or shortness of breath, can also occur. At highexposure levels, there is a risk of lung oedema (water on the lung).

SensitisationIsocyanates cause allergies, and the person who has become sensitivecan be affected by breathing problems at very low levels, far beneath

hygienic levels. The onset of problems is frequently delayed, and maytake several hours to develop. It is not unusual that problems do notoccur until the evening, or night, when you are at home. This situa-tion means that it may take a long time before you connect your prob-lems with the worksituation. A long period of exposure may also leadto reduced lung function. The exposure needed to trigger chronicproblems varies considerably between individuals. Some can sufferfrom asthma-like symptoms after only one, or a few exposures.

Both allergic and non-allergic contact eczema can be caused by skinexposure to isocyanates.

CancerThe only isocyanate, which is classified as carcinogenic in the Swedishhygienic limit list, is TDI. In animal tests, TDI exposure has caused anincreased frequency of various kinds of tumours and IARC (Interna-tional Agency For Research on Cancer, WHO) believes that there is“sufficient evidence” for stating that TDI is carcinogenous for animals.On the other hand, they believe that there is “insufficient evidence”to state that it causes cancer to people. Both TDI and MDI are regard-ed as mutagens (affecting genes), however.

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sensitising = develops over-sensitivity

lung oedema = water on the lung

mutagen = affects genes and inheritance

If you are already affectedIf you work with isocyanates and have already noticed problems withyour health, your exposure to isocyanates must stop. There are peoplewho, in the tough-working climate of the nineties, have kept theirhealth problem secret, to avoid loosing their jobs. There are evenpeople who use asthma medicines to be able to go on working. Theresult can be a chronic injury, which makes it impossible to work forthe rest of your life.

Action must be taken early, as soon as you experience the first symp-tom of a runny nose for example. Ask for help and support from yoursafety representative. If you belong to the company health care sys-tem, they should help you with preventive measures and rehabilita-

tion work. The basic requirement for connecting your health prob-lems with exposure at the workplace is that industrial hygiene mea-surements must have been done. Without these measurements, it isdifficult to relate your problems to your exposure. This is often arequirement for having your poor health classified as an industrialinjury.

Measurements are also a basic requirement for deciding the need foraction to be taken at the workplace. Follow-up measurements shouldalso be done to check that the measures taken have been sufficient.

It is thus of vital importance that these measurements should be done.If there is a company health care facility, they should have the com-petence and resources to help out. If not, other expertise should bebrought in from the Industrial Medicine Clinic, etc.

If you have problems in gaining understanding of your employer, forthe need to do the measurements, you should contact your industrialsafety representative if there is one. If necessary, the Labour Inspec-torate can demand it from your employer.

Report your problems as being an industrial injury to the SocialInsurance Office. If there are isocyanate exposure measurements, yourchances of getting the industrial injury approved are better.

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Risks and Exposure

When discussing the health effects of manufacturing polyurethaneplastics and other hard setting plastics, such as epoxy, ester and acryl-ic plastics, one talks about the free monomers. Monomers are small,independent molecules, which are highly reactive. The health effectsof isocyanates or other hard setting plastics are related to the occur-rence of these free monomers. This is why manufacturers of hard set-ting plastics have endeavoured to limit the occurrence of free mono-mers in the atmosphere as far as possible.

Monomers and other substances are released when hard setting plas-tic products are heated, together with other additives used in manu-facture. One of the additives whose effects has been the subject of alot of discussion is flame retarders.

Manufacture of PUR

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Figure 2. The highly reactive diisocyanate monomer is mixed with a diol,and the stable hard setting plastic product, polyurethane plastic, is formed in the

polymerisation reactions.

Monomer

Diisocyanate

By-products

Diols

Otheradditives

Polyurethane

PolymersDiisocyates and diolsbind to each other andform urethane

Hard setting plastic products containing isocyanates can be of thetwo-component or single component types. The single-componenttypes use the humidity of the atmosphere to harden.

Various measures have been taken to attempt to reduce the risks asso-ciated with monomers. One method used is to replace the more vola-tile isocyanates TDI and HDI with the less-volatile MDI. This canreduce the concentration of isocyanates as a gas in the atmosphere.Other methods are pre-polymerisation and blocking.

Pre-polymerised isocyanates Pre-polymerised isocyanates are formed by letting the monomersreact to a small extent in advance. This reduces the amount of freemonomers, and also reduces volatility. A hardener is then added topromote final hardening. This procedure has sometimes been used bysome manufacturers, to claim in the product information brochure,that there are no isocyanates in a product.

Blocked isocyanatesAnother method used to reduce the health effects is blocking of theisocyanates. The method is intended to reduce the amount of free iso-cyanates, which can float freely in the air breathed in. The isocyanatemonomers are bound by means of the blocker. Heat is frequentlyneeded to release the isocyanate monomers and start the hardeningprocess. Blocking of isocyanates is used in paint manufacture, forexample. Unfortunately, blocking has also been used by many manu-facturers to claim in the product information brochure that there areno isocyanates in a product.

The finished PUR productDepending on the mixing ratios, free isocyanate groups can be foundin the finished product. Isocyanates can also react with high humidity

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Monomer = small, free, highly reactive molecule suchas diisocyanate or diol.

Polymer = molecules which have been bound to eachother in great numbers (plastics).

Polymerisation = chemical reaction where small moleculesare linked together to form a polymer.

in the air to form amines, which can be found in the finished PURproduct. The aromatic amines, which can be formed, include MOCA,TDA and MDA. These substances are included in the National Boardof Occupational Safety and Health hygienic limit list under group Bsince they cause cancer. Substance in-group B may only be handled inindustry if permission is granted by the Labour Inspectorate (YI).Permission is normally granted only if absorption in the body can beprevented.

One problem with the current rules for these amines, found on the Blist, is that permission is only required when the products are purchas-ed. There are no rules for amines formed at the workplace, since thereare no hygienic limits for substances on the B list. The National Boardof Occupational Safety and Health has ordered criterion documentshowever, to allow hygienic limits to be set for these substances as well.

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In the glass ware industry, products are placed on fibreglass sheets containing PUR.Upon heating the PUR is decomposed and isocyanates are released.

Amines are also frequently added to control and facilitate the poly-merisation process. Depending on the properties required in the fin-ished product, diols can be replaced by diamines. There have beendiscussions about the levels found in materials such as mattresses,cushions, earplugs and other light foam products used close to theskin, on account of the negative health effects of aromatic amines.

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Aromatic = Unsaturated molecule, often ringshaped – to be compared with

Aliphatic = Saturated molecule, frequently straight in shape

Amines = A type of molecule which containsnitrogen

MOCA, TDA, MDA = Aromatic amines

Figure 3. When polyurethane is heated, it breaks down, and free monomers andother substances are formed.

Applying heat to PURWhen the PUR is thermally decomposed many different isocyanatesare formed. In addition different amines such as MOCA, TDA andMDA may be formed. Detail information of many of the formedcompounds are sparse.

The decomposition products are to be found in both gas and particlephase and the composition depend on the formulation of the actualpolyurethane polymer.

Polymers Monomers

amines

diisocyanate

diol

other substances

Heat

AdditivesA large number of additives are used in making PUR and other plas-tics materials, to give products the desired properties. Some examplesof these are pigments, anti-static compounds, flame retards and bio-cides. Many of the chemicals used for this are also extremely contro-versial because of their effects on both the working environment andthe external environment.

The fire retards used which are most in focus are the chlorate or bro-mide organic compounds (halogenated). These compounds cause can-cer, are difficult to break down and are accumulated in living organ-isms. Chlorate and bromide compounds have begun to be replacedby phosphate esters, which have similar properties. Knowledge ofthe effects of these substances is deficient, although many people areexposed. Personnel who work with electronic equipment or otherflame-protected products such as textiles, furniture and cars are ex-posed. The considerable increase in the levels of bromided flameretards in mother’s milk gives an illustration of the severity of the risksassociated with these substances.

Our ability to track product use in the global chemical industry andto analyse the new substances which occur is far too limited. Thestrategy for chemicals, which Sweden has initiated in the EU, de-mands better chemical analyses and that the most dangerous chemi-cals should be phased out.

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biocides = additive to stop biological break-down

phosphate esters = organic compound containingphosphorous

chlorated compounds = organic substances containingchlorine

bromided compounds = organic substances containingbromine

halogenated = organic substances containingchlorine, fluorine, bromine oriodine

pyrolysis = thermal breakdown

LO believes that a ban on the most dangerous flame retards such asthose containing halogens, should be introduced to speed up devel-opments towards non-hazardous flame retards.

Further research neededWe see these days that isocyanates have serious effects on health.People are expelled from the working force because they have devel-oped oversensitivity and asthma.The current situation with the strongcutbacks in resources for research in chemicals makes the situationserious. Constant changes in workplace, with the use of new sub-stances and production methods puts constant new demands on re-search capacity.

PUR for just about every link in the industrial hygiene chain know-ledge is still incomplete regarding the industrial use of PUR. Onlysketchy information exists regarding hot work in PUR and heating ofproducts similar to Bakelite, containing formaldehyde, phenol andurea.

Deficient methods of measurement have given an incorrect picture ofexposure, especially as regards hot work. No consideration has everbeen given in assessments to particles containing isocyanates.

This situation has meant that research on the medical effects has notbeen able to interpret correlations correctly. Many of the past surveys,using incorrect exposure measurements, are only of limited valuethese days.

The following questions are the most urgent:

● How poisonous are various types of isocyanates and amines com-monly found in industry?

● How poisonous are the various types of additives used?

● What importance does skin absorption has for the development ofasthma?

● Is a single high-level exposure enough to give chronic injury andasthma?

● What level of importance does exposure to particles, aerosols andgases have?

● What is the correlation between exposure and biological levels?

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● What should an acceptable diagnosis method for isocyanate relatedillness look like?

What do alternative, less hazardous systems look like?

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Measurement ofIsocyanates

Measurement of isocyanates is a complicated task. There are manydifferent varieties, the levels are very low and they are very reactive.The method used in Sweden in the 70s and 80s was based on use ofa so-called impinger flask.

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The flask contains a reagent (a fluid) which the isocyanates are boundto. The reagent used at that time was methylaminomethylanthracene,commonly referred to as MAMA.

Suspicions arose in the mid 90s that the method did not work well inall situations. It was Dr. Gunnar Skarping and his research team inLund who found from biological testing that personnel who had thetypical symptoms of isocyanate-related problems had also been sub-jected to exposure, although atmospheric measurements had shownvery low values. It was found that exposures could be seriously under-

Figure 4. The figure shows an impingerflask connected to a glass fibre filter.An air-sampling pump is used to giveprecise air flows and volumes.Isocyanates in the gas phase and largeparticles are collected in the impinger-flask where as small particles are col-lected on the glas fibre filter.

estimated by MAMA measurements in the more complex chemicalenvironments. In some cases, no levels at all were found, and in othercases the results could be thousands of times lower than the truevalues.

This was very serious, since the MAMA method was the method usedto check that hygienic limits were not exceeded. It was also usedwhen the reasons for poor health were investigated. There are cer-tainly many who have been affected, but who have never been able toobtain confirmation that their problems were caused by isocyanates atwork.

Many companies have also been granted exemptions from doing fur-ther measurements in their working environments, on the basis ofmeasurements with this misleading method. LO believes that theseexemptions should be withdrawn.

Gunnar Skarping and his colleagues have developed the methods ofmeasurement. Their first act was to replace the reagent in the imping-er flask with dibutylamine (DBA). DBA requires that analyses shouldbe done with a mass spectrometer however.

The method has been further refined after measurements in car work-shops. The reason is that the impinger flask does not trap the smallestparticles in the air. A filter has therefore supplemented the impingerflask. Figure 5 below shows the results from measurement at carworkshops using this method. The results show that exposure to thesmall particles can add a considerable quantity of isocyanates to theenvironment. The figure also shows that exposure via particles alsoincludes less volatile isocyanates, such as MDI etc. Developmentscontinue, and measurements in the near future may use a dry method,without an impinger flask.

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Exposure measurement for isocyanatesRisk evaluations through exposure measurements at the workplacemust be sufficiently comprehensive that they give a clear picture ofthe substances and levels to which a worker is exposed. Regulationalso stipulates that the results of measurements should be document-ed and saved.

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Figure 5. The figure shows air concentrations of isocyanates during cutting inpained car metal sheets. Three different air samples were taken and gas

and particle phase isocyanates were determined. It can be observed that the mostvolatile isocyanates (MIC) is only present in gas phase where as the much less

volatile isocyanate MDI is predominantly in the particle phase.

Grinding Cutting Brushing Welding

Various direct-reading instruments are commercially available, such asthe Isolog. This instrument is not reliable in establishing absolutelevels, but is excellent for use as an indicator. The instrument is veryvaluable for use in preventive measures, since it gives direct informa-tion about the tasks, which give high levels of isocyanates.

Isolog = a direct indication instru-ment for isocyanates

Mass spectrometry method = an advanced, highly sensi-tive method for determiningthe type and levels oforganic contamination whichoccurs

The safety representative shall participate in planning and setting upmeasurements. Measurements shall be done by persons who have suf-ficient competence for the task. Measurements should normally bedone by industrial hygienists or industrial safety engineers, who havereceived further training in industrial hygiene measurement, and alsohave training in isocyanate measurement.

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Air passages and lungs are injured by high concentrations of isocya-nates. There are suspicions that single, short exposures to high con-centrations can be enough to cause injury, even if they only occur onisolated occasions. Average measurements of hygienic levels are thusnot enough. Nor can the peak limit exposure on the average of a 5-minute exposure be regarded as sufficient. In some cases, a direct in-dication instrument such as the Isolog can be used.

Measurements shall be done with the DBA method, supplemented bya filter, or with another method which is developed and has corre-sponding performance or better. The results of all analyses should bedocumented, given the background of our incomplete knowledgeabout exposure and effects, including levels of isocyanic acid andamines where found.

Biological samplingChecks on exposure at the workplace should be based on estimates ofthe worker’s environment in the first hand. Risk evaluations in the

Simultaneous monitoring of isocyanates using impinger-filtersampling and a continuous monitoring device.

form of industrial hygiene exposure measurements shall always bedone if there is a risk of exposure, which could cause injury. Experi-ence with isocyanates shows that these measurements do not alwaysreflect the true exposure. Air measurements do not catch the expo-sure due to skin or stomach/intestines, whose importance in variouskinds of effects is still uncertain. In other countries, such as Germany,biological test methods are used for isocyanates.

LO believes that each individual should be given the right to biologi-cal testing in cases of poor health or in conjunction with regular test-ing. If this right was available as an extra check when requested by theindividual, mistakes in preventive environmental work could be dis-covered. The right to biological testing should be available for expo-sure to isocyanates for which analysis methods have been developed.These are TDI and MDI at present.

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Training

The presence of various forms of isocyanates is very common in manyindustries and areas. In some cases, this is because products, whichcontain free isocyanate monomers such as paints, adhesives, joint seal-ers, varnishes etc. are handled. In other cases, it is because finishedproducts containing PUR are heated, whereupon the compoundsbreak down and form free isocyanates. Isocyanates are also formedwhen products containing formaldehyde, phenol and urea are heated,such as Bakelite, mineral wool, circuit boards etc.

LO believes that all persons who work with these substances or whoheat material resulting in the generation of isocyanates should receivetraining. Awareness of the importance of preventing exposure isnecessary for everybody. This also applies to people who have tempo-rary or fixed time appointments, or are supplied by an agency.

Experience has shown that the hard setting plastic regulations areunknown in many cases. An example of adherence to rules can betaken from the Labour Inspectorate, who inspected industrial paintingin Östergötland province. The companies visited worked with en-gineering, woodworking, sub-contract painting and other activities. 75percent of the companies who used hard setting plastics did not knowabout the rules in the Hard setting plastic Regulations.

There is a strong need to improve knowledge. A good start is thatbasic knowledge of hard setting plastics is given in the relevant voca-tional training courses. It is necessary for the teachers to have therequisite competence, for this to occur. LO believes that the SchoolsBoard should be responsible for ensuring that teachers get furthertraining in working environment matters. The certification of com-petence in the hard setting plastic field can also take place.

The scope of the training needed can vary-, for the professional groupsalready out at work. The basic requirement is, however, a courseequivalent to the Joint Industrial Safety Council hard setting plasticmaterial, supplemented by knowledge of the relevant working situa-tion. A one-day course is a minimum union requirement for all kindsof hard setting plastic work. Safety representatives and supervisors

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should also have more comprehensive training. It is a good idea if thescope of training in each industry were regulated by general agree-ment between the various bodies in the labour market. The agree-ment should also stipulate the interval for refresher training in thehard setting plastic field.

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Personal ProtectiveEquipment

Personal protective equipment is the last resort for solving problemsof exposure at the workplace. Measures to be used in the first handhave failed, such as replacing products containing isocyanates by lesshazardous encapsulation or other technical measures. Many situationsexist where personal protection equipment is the only way to protectyourself, such as in accidents, discharge, fires etc.

Breathing protectionThe National Board of Occupational Safety and Health hard settingplastic regulations require that at least a half-mask and carbon filtermust be used. This is no use, however, against methyl isocyanates oflow molecular weight (MIC). The reason that the regulations do notconsider MIC is that there was no knowledge about them at Swedishworkplaces when the regulations were issued. MIC is formed whenmineral wool and other products containing the three components offormaldehyde, phenol and urea are heated. A full mask supplied bycompressed air should be used instead.

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The use of fresh air respiratory protection device during grinding.

In discussions about personal protective equipment related to isocya-nate work, it has been found that some makes of half masks do notprovide the promised protection factor in practice, despite CE mark-ing. The marking should indicate that the demands in the directive arecomplied with. The effect is that some of our members are subjectedto exposure although they have taken the precautions and believethat they are protected. LO believes that it is serious if inadequatequality is commercially available.The National Board of OccupationalSafety and Health should be responsible for ensuring that all com-mercially available masks are tested. Reports should be sent to manu-facturers whose products do not meet the quality requirements.Changes to current standards may also be needed.

Given that carbon filters are of no use when workpieces are heated,and that the protection factor can frequently be dubious when a halfmask is used, LO believes that compressed air supplied breathing pro-tection should be used in all regular isocyanate work.

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Protective gloves, protective clothing and eye protection

The pictures show the applicationof synthetic polyurethane casts.The polymer hardens after squeez-ing the PUR-impregnated bandagein water. Amines can be found inthe water.

Isocyanates are highly irritating and sensitising for skin and eyes aswell. This means that unprotected hands, which have been exposedto isocyanates, can contribute to the development of over-sensitivity,which can affect the skin and breathing passages. It is thus very impor-tant that you should protect yourself with gloves, goggles and otherprotective clothing if needed to prevent contact with isocyanates.Note that both isocyanates and amines quickly penetrate ordinaryplastic gloves. The only safe glove commercially available is the 4Hglove, which is relatively clumsy, however. Changes of clothes andgood hygiene are necessary. If there is any risk of splashing, an emer-gency shower should be available nearby.

Plastic bandages are frequently used in the medical care sector thesedays, instead of plaster casts. The bandage hardens when wetted withwater, at which point amines are released in the water. If an ordinaryoperation glove is used for this work, it does not take long until theskin is exposed to free amines.

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Manufacturers andSuppliers

The basic philosophy behind our views on handling of hazardouschemicals is that they should be replaced by less hazardous ones (theso-called substitution principle). The principle should be applied toboth the working environment and the outside environment. Thisconcept has been applied for some time in Swedish regulations, and isnow applied in EU regulations. This is the basic standpoint in theChemicals Inspectorate and the National Board of OccupationalSafety and Health regulations. This principle should of course beapplied to isocyanates as well. One prerequisite for this to happen isthat the information in the product information brochures must beaccurate.

The Chemicals Inspectorate is the supervisory body for the chemicalsuppliers in Sweden. Since the LO chemicals group has been able tofind deficiencies in companies’ product information, the following let-ter was sent to the Inspectorate in 1998, see next page.

This note has not resulted in any major changes so far. A meeting withthe personnel from the supervision unit at the Inspectorate has takenplace, however. It was stated at the meeting that all supervision isdone by only three people and that there is no realistic opportunityfor carrying out more active supervision. The police reports made bythe authority must be done on the basis of a visit to the company inquestion. The reports, which have been done with the current man-power, frequently do not lead to charges being brought or any notice-able punishment.

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Workers’ health and company’s consideration for the ex-ternal environment is completely dependent on knowledgeof the content of chemical products and the effect of thechemical components. A decisive factor for ensuring thatcorrect assessment is done at the workplace is that productmarking and product information brochures contain thenecessary information.

The Joint LO chemicals group has discussed several ques-tions related to the current situation with product informa-tion brochures. Improvements to the current situation mustbe achieved by improved application of current legislation.

After discussions with representatives from the affiliatednational unions, LO has found that there are three problemsassociated with current application.

1. Companies who fail to follow the rules through intentionor negligence do not risk any sanctions in practice.

2. Substances, which can give a negative effect on health,are not noted in the information, with the motivation thattheir content is less than 1%, for example. It also occursthat only some of the substances are specified, althoughvarious substances in the group may differ in their haz-ardous effects.

3. Harmful effects are possible from hazardous substancesformed during thermal breakdown when the finished pro-duct is worked on, such as paints, adhesives, plasticsetc.

Given the background of current conditions, LO believesthat a review of the application of current legislation shouldtake place. LO affiliates and LO are available for further dis-cussions and views.

The Swedish Trade Union ConfederationWanja Lundby-Wedin

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LO’s letter and the environmental scandal in the railway tunnel underHallandsåsen have started a debate on product information suppliedby companies, however. Several organisations are interested in im-proved product information, both among chemical suppliers and em-ployer organisations. Many improvements will likely be made volun-tarily in various industries, but these probably will not be sufficient

LO believes that resources and knowledge must be available to publicauthorities and the public prosecution service, so that the sanctionsystem in the law will also function and be applied when productinformation is not observed.

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Regulations andSupervisionThe National Board of Occupational Safety and Health is the centralpublic authority which issues regulations where the demands onindustrial environment work in companies is specified, under theIndustrial Environment Act. The Labour Inspectorate maintains aregional presence throughout Sweden, and conducts inspections atworkplaces. The cut-backs in recent years mean that the resourcesavailable to the Labour Inspectorate have been reduced so far thatSweden is clearly the lowest in the Nordic area for the number ofworkers per inspector.

Companies are not particularly inclined to observe the regulationsissued by the National Board of Occupational Safety and Health. Oneof the main regulations requires employers’- to conduct inspections ofindustrial environmental work in companies. According to theNational Board of Occupational Safety and Health own surveys, onlyabout 42 percent had functional internal inspection, among com-panies with 5–49 employees. The figure was only 13 percent amongthe very smallest companies.

LO believes that the rules in the industrial environment field shouldbe observed, and demands better resources for the Labour Inspector-ate and the regional safety representatives.

The most important regulation related to isocyanates at the work-place is “Hard setting plastics”.The regulation covers hard setting plas-tics in general, i.e. including epoxy, esters, acrylics, cyanoacrylates,amino plastics and phenolic plastics in addition to urethane plasticsbased on isocyanates.

One problem with the regulation is that various trades do not under-stand-, or know that they are affected by the regulation. How shoulda shoemaker who uses isocyanate adhesive or a repair worker whowelds PUR coated material understand that he is affected by the Hardsetting plastic Regulation? LO believes that the name of “Hard set-ting plastics” contributes to the fact that many trades do not under-stand that they are affected.

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The Hard setting plastic Regulation includes the provisions that:

● Everybody who works with hard setting plastics should have train-ing.

● Hard setting plastic components should be mixed in a closed sys-tem, or in a separate, well ventilated area.

● Hot work (such as welding, soldering, grinding) must not be donein such a way that the plastic is heated unless special measures havebeen taken to prevent exposure to air contamination.

● Workers must make sure that exposure measurement is done ifhazardous air contamination could occur due to handling of hardsetting plastic components.

● Measurements must be documented.

● Employees must go through a health check before any work withhard setting plastics is done.

● Enhanced medical checks shall be done if isocyanates, cyanoa-crylate or organic acid anhydrides occur, including a test of lungfunction. A follow-up shall be done after 3–6 months, and thenevery second year.

Applicable paragraphs are found in their entirety in AFS 1996:4 Hardsetting plastics.

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Spirometry is used for the measurement of the lung capacity.

LO believes that a revision of The Hard setting plastic Regulation isnecessary, given the background of the new knowledge which hasarrived since 1996. The suspicion that a single, heavy exposure cancause permanent over-sensitivity must be given special attention, inrespect to exposure at temporary workplaces. LO believes that a par-ticularly high protection level must be maintained irrespective ofwhether a workplace is temporary or permanent.

In addition, a review of the following must be made:

● increased clarification of the jobs affected by the regulation

● clarification in relation to hot work and training

● heating of products containing formaldehyde, phenol and urea

● opportunity for workers to have a biological test of exposure

● rules for aromatic amines found on the B list which are formed inindustrial processes

● rules and recommendations for personal protective equipment.

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Measures at the Workplace

The general rule for chemicals at the workplace is substitution. Theincreased use of polyurethane plastics has mainly taken place in atime when measurement methods for isocyanates have been inade-quate. This means that we have not been able to see the correlationbetween poor health and the working environment.

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We now have methods for measuring more accurately-, and can statethat some car paints contain more isocyanates than others. The samesituation applies to adhesives etc. This new knowledge does not onlyallow us to see correlation between exposure and poor health; it alsoallows us to reject isocyanates if there are alternatives available

Well-functioning substitution work in companies is based on correctproduct information being available for the products used. The pro-duct information brochures must state whether isocyanates occur inproducts in any form. The health risks and the protection measuresnecessary should be easily understandable, from reading the productinformation brochures.

Windows are mounted using a non-isocyanates containing glue.

Even when product information brochures function well, exposurecan still occur at workplaces. The reason is that material or productscan be heated when a product information brochure would not berelevant, such as repair or maintenance work. Workers who are occu-pied with this type of task suffer a considerable risk of isocyanateexposure. Hard setting plastic training should therefore be obligatoryfor this category of workers.

If accidents at workplaces mean that employees are exposed to highlevels, an investigation of the consequences must be done. Exposurechecking by means of biological testing should be done and the resultsshould be saved. Measures should also be taken to prevent a repeti-tion.

There are various types of compounds available for isocyanate andamine decontamination in premises and equipment. There are alsocorresponding products for use on skin. There is also a cream, whichreduces skin absorption.

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A mobile booth can be used to isolate the ”isocyanates work” in the car repair shop.

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If it is not possible to avoid products, which contain isocya-nates, or if isocyanates are formed by heating, the followingmeasures must be taken:

● Handing shall be isolated from other activities, in a sepa-rate area with lower atmospheric pressure than in adja-cent premises.

● Workers who do the work must be provided with breathingprotection with a compressed air supply.

Union Check List

✓ The internal inspection regulation rules and other National Boardof Occupational Safety and Health regulations must be applied. Inaddition to The Hard setting plastic Regulation there are rulesfor air contamination and hygienic limits, plus general rules aboutchemicals use at the workplace.

✓ The employer must do a risk evaluation, which shall be document-ed as regards chemicals at the workplace.

✓ If exposure occurs at the workplace, industrial hygiene measure-ments must be done so that the exposure pattern of the victims isclearly documented. The measurement reports must be saved.

✓ Plans shall be drafted for long term and short term corrective mea-sures.

✓ There must be a collected register of all chemicals used by thecompany.

✓ Product information brochures should be evaluated before pro-ducts are ordered. Choose the least hazardous product, whichserves the purpose. A product, which lacks product information,should never be handled. A good rule is that products, which lackproduct information, should never come inside the gates. Changesupplier if product information is poor or missing.

✓ Use the company medical service or other industrial hygiene ex-pertise for choice of products, industrial hygiene measurement andfor help in proposing corrective measures.

✓ Contribute to taking swift measures if anybody feels symptoms dueto isocyanates. Even if a transfer has to be done, measures must betaken to reduce risks at the workplace, so that more workers arenot affected. The company medical service is a resource for bothmeasures at the workplace and in rehabilitating the affectedpersons.

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Make sure that the rules in the Hard setting plasticRegulation are observed. Use a compressed air mask andother necessary protection equipment. Ask for help fromthe industrial safety representative, regional industrialsafety representative, Labour Inspectorate or union branchif you suspect that working conditions are hazardous andthe employer refuses to take measures. If you work aboarda ship, you can also ask for help from the NationalAdministration of Shipping & Navigation. It is your health,and your workmates’ health, which is in the balance.

Read More

Training material for Hard setting plastics with associated OH package

A series of brochures containing information about risks andmeasures to be taken:

Do you work in a car or truck workshop? Part no. 5212

Do you work in the electronics industry? Part no. 5213

Do you work with isocyanates or polyurethane? Part no. 5214

Do you work with bonding or with bonded components or products? Part no. 5215

Do you work with painting or varnishing, or withpainted/varnished components? Part no. 5216

Do you work with foam plastic or insulation foam? Part no. 5217

Do you work with welding? Part no. 5218

Do you work in the building trade? Part no. 5219

This material can be ordered from the

Joint Industrial Safety Council,Box 3208, S-103 64 Stockholm,Phone 08-402 02 00, fax 08-21 01 52.

The series of brochures is free and is also available at www.asn.seunder the heading of Support and service.

Hazardous substances (AFS 1994:2)

Hygienic limits (AFS 1996:2)

The Hard setting plastic Regulation (AFS 1996:4)

Internal inspection regulation (AFS 1996:6)

Order from the National Board of Occupational Safety andHealth publication service,Box 1300, S-171 25 SOLNA,phone +46 8-730 97 00, fax +46 8-730 98 17or downloaded from www.arbsky.se

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ABBREVIATIONDBA Dibuthylamin

HDI Hexamethylene diisocyanate

ICA Isocyanic acid

MAMA Methylaminometylantracen

MDA Methyldianilin, aromatic amin

MDI Methylene bisphenylisocyanate

MIC Methyl isocyanate

MOCA Methylenbis(o-kloranilin), aromatic amin

TDA Toulendiamin, aromatic amin

TDI Toulene diisocyanate

GLOSSARY OF SELECTED TERMSAliphatic Saturated molecule, frequently straight in

shape

Amines A type of molecule which contains nitrogen

Aromatic Unsaturated molecule, often ring shaped– to e compared with aliphatic

Biocides Additive to stop biological break-down

Bromided compounds Organic substances containing bromine

Chlorated compounds Organic substances containing chlorine

Halogeneted Organic substances containing chlorine,fluroine, bromine or iodine

Isolog A direct indication instrument forisocyanates

Lung oedema Water on the lung

Mass spectrometry An advanced, highly sensitive method for method determining the type and levels og organic

contramination which occurs

Monomer Small, free, highly reactive molecule such asdiisocyanate or diol

Mutagen Affects genes and inheritance

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Phosphate esters Organic compound containing phosphorous

Polymer Molecules which have been bound to eachother in great numbers (plastics)

Polymerisation Chemical reaction where small molecules arelinked together to form a polymer

Pyrolysis Thermal breakdown

Sensitising Develops over-sensitivity

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LO demandsthat public authorities, organisations and private companies should

collaborate on the goal of creating greater awareness about theserious risks caused by isocyanates and of preventive measures inSweden, the EU and internationally

that everybody who handles products and material which – in hot orcold work – can emit isocyanates should have at least one day’sisocyanate training,

that all use of isocyanates is replaced by less hazardous substances,

that research resources in the industrial environment field in general,and the chemicals field in particular, are enhanced,

that the Chemicals Inspectorate is given more facilities to carry outsupervision, so that the rules relating to product information arefollowed,

that developments towards the development of non-hazardous flameretarders is speed up by banning the hazardous ones,

that rules in workplace should be observed, which requires betterresources for the Labour Inspectorate and the regional safetyrepresentatives,

that the Schools Board should take measures as soon as possible toimprove the competence of teachers in all vocational training, asregards hard setting plastics and working environment regula-tions,

that exemptions based on measurement results using old measure-ment methods should immediately be withdrawn by the LabourInspectorate,

that the National Board of Occupational Safety and Health shouldimmediately revise the relevant regulations, on the basis of thenew knowledge,

that biological testing should soon become a right for all workersexposed to isocyanates or amines,

that compressed air breathing protection should be used for all regu-lar isocyanate work,

that risk evaluation in relation to chemicals exposure should containdocumented industrial hygiene exposure measurement so thatthe exposure picture for the persons exposed becomes clearer.

One of the core tasks of a trade union is to monitor technical devel-opments with great attention, with the goal of preventing injury topeople and damage to the environment.

New knowledge shows that symptoms such as asthma and aller-gies can be explained by exposure to isocyanates at the work-place. However, poor methods of measurement have thus far con-cealed the correlation between poor health and work.

This brochure contains union demands for measures to reduce therisks to which workers are exposed, given the current level ofknowledge.

The measures demanded contain improvements to:

● Research

● Product information

● Training

● Rules and resources for supervision

● Measurement

The union urges that public authorities, organisations and privatecompanies collaborate in the goal of creating greater awarenessabout the serious risks caused by isocyanates, and of preventivemeasures in Sweden, the EU and internationally.

www.lo.se