mfety in the chemkd laboratory

edited by MALCOLM M. RENFREW

University of idaho MOSCOW, ldaho 83843

An Undergraduate Chemical Laboratory Safety Course L. Jewel Nicholls University of Illinois at Chicago Circle, Box 4348 Chicago, IL 60880

In all college laboratory courses, students are introduced to safety principles as soon as they are assigned laboratory work involving chemicals. This continues throughout their lives as they work in laboratories and plants. At some point each person becomes respon- sible for his own laboratory safety and that of others. This means that he must be able to make judgments based on sound principles or on research into specific hazards. He must be sure enough of himself that he can advise others with confidence and authority.

Safety topics which are useful to an un- dergraduate student are similar to those presented to industrial groups for plant

L. Jewel Nlchoiis received her BS hom Monmouth College and her PhD from the University of iilinois at Chicago. She is presently the Coordinator of the Under- graduate LabaatwieJand S t m m a t the University of iilinois at Chicago Circle where she developed the course she describes in this oaoer under the ausoices of an NSF . . grant rler researcn interests lie in me t eid ol onorganic chemistty particularly the rte- reochemisq of metal mpierer emmining chirai donor atoms, as well as in thedevei- opment of materials for safety eoumes and safe laboratory experiments.

safety. However, the types of assignments and class exoeriences which will helo the student to apply chemical safety prinripl~s ro his rhenkal laboratory operations are of a deeper nature and involve more uf a prob- lem-solving approach.

How does one get such a course to fit in with a chemistry curriculum? Since the scope of such a course is based upon chemical skills at the eolleee level material mav be l resented ~~ ~~ ~ . . . . a hivh helps students to understand safety at a mow qumlitativeand theoretical level by applicatiun of principles of equilibrium, k i - netics, free energy of concentration, and gas laws to real situations.

The safety course offering at UICC is Chemistry 283, a two-quarter-hour course which meets two hours a week usually in a classroom, but occasionally in a laboratory. The offering is an alternative to the required literature course for the BA degree. It is an elective for Bachelor of Science candidates and students in other fields, such as biology and engineering. The prerequisite is organic chemistrv. Students who have taken the lab ~ ~

safety cuurse are mainlv those interested in industrial ehrmistry. However, students in- terested in teaching or graduate srh~ml have also taken it.

I feel it will be useful to adopt the texts: "Prudent Practices for Handling Hazardous Chemicals in theLahoratorvn (1 ) . Volume 3 . . . . of "Safety in the Chemical Laboratory," edited by N. V. Steere (2), and Volume 4 of "Safety in the Chemical Lahoratory," edited hy M. M. Renfrew (3). "Prudent Practices . . ."was published by the National Research Council with input from prominent scientists as an alternate approach to OSHA regula- tions, since conditions in research and teaching laboratories differ from those in industrial settings because of the different scope, untested chemicals, level of compe- tence, and short exposures involved. Volumes 3 and 4 of "Safety in the Chemical Labora- tory" have in-depth articles on many of the topics which lend themselves to good prob- lem-solving exercises with which chemists must deal. "Prudent Practices . . ." has the advantage uf good organrratam, reasonahle p r m , guod hbl~ogmphy, and recent publr- cation.

I have been using as a text Volumes 1,2,3 edited by N. V. Steere: "Safety in the Chemical Laboratory" (2). A course outline using this as text was published by Lowry (4). This has a few drawbacks hut has been the

best choice up to this time. It is not organized as a single text, and the articles range in depth and applicability. It has the advantage of in-depth coverage of relevant topics pre- pared by experts in that field. A combination of "Prudent Practices . . ." and Volumes 3 and 4 of Safety in the Chemical Laboratory give the organization plus the depth required for such a course. Neither has problem sets or sets of questions useful for class assignments. Another hook which may he used as a text is a paperback by Green and Turk (5) con- taining basic material which may be supple- mented as I have indicated in Tables 1,2, and 3. The text by Meyer (6 ) is useful for classes

(Continued on page A3021

Malcolm M. Renfrew draws on varied industrial and academic experiences in his approach to good safety practices. After graduate study at the University of Mime wta, he was a supervisor of research and development with DuPont and General Mills: then an administrator and teacher at the University of idaho, his Alma Mater. He is active in the American Chemical Society. including service with the Commitlee on Safety and the new division of Chemical Health and Safety. He now is professor emeritus of chemisby and is patent director of his University's ldaho Research Faunda- tion. Inc.

Volume 59 Number 10 October 1982 A301

wi th less background in chemistry-fire fighters, for example. It explains emergencies in terms o f basic physical properties. This book has the advantage that it has problem sets a t the end o f each chapter.

A text b y Fuscaldoet al., (7) could be used in a courseat the college level where the em- phasis is on biohazards. In addition to this content it bas excellent sections on radiation hazards and behavioral factors in laboratory safety for personnel which are not covered as well, if a t all, in other texts. I have worked uo a svllabus based uoon . .

'Prudmr Pror tws. . ." 1 1 , and the thinl and fourth w l ~ m r i of "Safrt) in the Chemical LR~UTAI~W)." (2. 3,. The number uf Ircturpa for each topic, pages assigned, and related class or assigned activities are found in Table

Safety: A Protective Device for D-l-Y Electrical

Workers Winston C. Nottingham Universihl of the District of Columbia Washington. D.C. 20008

When using do-it-yourself (D-I-Y) or "homemade" electronic laboratory equipment it is sometimes possible to experience a severe electrical shock. An installed fuse serves as a safety device t o protect the equipment; however, it usually does no t respond rapidly enough to ensure personal safety.

T h e Ground Fau l t Interrupter IGFI ) is desiened t o react almost in- stantlv t o a e k u n d fault or short and ~, ~ ~~~~~ ~ ~ ~ ~ ~~~~

will ~ ~ t ~ r r u p t the fluw o f current he- fur? a lethal s h ~ c k occurs. E lwt r iv i ty follows the path o f least resistance. I f a ground faul t occurs, some o f the neutral current w i l l f low in the grounding path (grounding conductor oi person's body). Therefore, less current w i l l flow in the neutral wire than *ill flow on the "hot" wire. I f the difference is 5 f 1 mA, the GFI wi l l trip in a few milliseconds. Here, the GFI's function serves to stop the cur- rent flow before one receives ~ersona l injury.

GFI's are available in several dif- ferent types, i.e., circuit breakers, re- placement receptacles, and portable plug-ins. The cast wi l l vary, starting a t about $30. The minimal cost associ- ated w i th the replacement receptacle type GFI makes it a bargain for the increase in safety. A l l G F I devices come w i th clear and complete wiring instructions and a test procedure.

EDITOR'S NOTE: Campus safety officers may take a d i m view o f do- it-yourself electronics and also may have established procedures on the use of ground fault interrupters.

Table 1. Topics and Assignments for a Laboratory Safety Course

Pages Prud. Pages Pages Lecture Pract. Steere (21 Renfrew (3).

T o ~ i c Hours f 11 Vol. 3 VoI. 4

Introduction Toxicology

Personnel Protection Corrosive Chemical

Hazards Flammable Hazards Explosive Hazards

Storage and Disposal

Pressure Systems Equipment and

Radiation Ventilation and

Monitoring Philosophy of

I ah Safehr

Table 2. Problem Sets

A. TOXICOLOGY PROBLEMS Answer the following questions as completely as possible showing calculations where required:

1. Consider methacryiic acid fw which emies may be found in many toxicolagy references (see reading lisB.

a1 What IS the east Concentratton *hch may cause a dean in humans? bl It Inere were no aata from stmes on h.mans. what mognl you say aboffl me tox c effecl on

humans? From animal data? C) What are the toxic effects on (a) short exposure? (b) long exposure? d) What precautions must one take if one is to work with methacrylicacid? e) Using any source of data, cite the toxicity of methacrylamide as it compares with mathacrylie

acid. Think of a reason why this may be true based on logic from Carter and Fernando (6). 2. The TLV for chloroform is 50 ppm (240 mg/M3) at 25"

a) Translate this to vapor pressure in mm Hg. b) This is a ceiling value. Haw is the TWA related to the TLV?

3. The TWA for orthotoluene is 5 ppm (USOSair). if the usual concentration of orthotoluene is 1 ppm. except for a 30-minute period when the level is 150 ppm, is the TWA exceeded? Show calcula- tions.

4. Disc~ss three wavs in which toxic substances interfere with metabolism. 5 A combmat on of mcrel wbonyl and dnoorane leakw ntothe a r n a aoorstw Mon torlng4evces

showed tnat the concernrat on of mcrel caroony *as 0 0007 ppm an0 lnal of 0 borane 0 05 at 25' Ass~me the effect is add w e an0 calcu ate rhether tne thresnod irmot value was exceeaeo 1-V values are part of the assigned reading.

6. What is a teratogen? Are teratogenic effects limited solely to exposures in women? 7. HOW are mutagenic effects different from those of teratogens? Compare both to embryofeta-

toxins. 6. If the LOSO for hexanoic acid is 2050 mg/kg for a rat, what approximate dose far a 160-pound man

mioht have a similar effect? 0 ~~~~ ~ - ~~ - ~~~

a) What assumptions must be made in the extrapolation of toxicihl data from rat to man? b) What precautions, if any, must be taken when working with hexanoie acid?

9. What accidental means of injection of toxic agents is most likely to be the case in a typical research or teaching lab?

B. STORAGE PROBLEMS

1. If YOU were to a m g e a storage area for a kilogram w m e of each of me classes of materials listed below, indicate the kind of storage you would choose, and what kinds of materials must be ananged away from &em If alphabetical listings an shelves is impwtant, how many of these separate listings will be most advantageous so that dangerously incompatible substances will not be in contact with each Other. Other choices of storage facilities may be refrigerator, solvent cabinet, or exterior Separate Storage building.

Inorganic oxidizing acids, fiammable solvents, solid hydrocarbons, cyanides and sulfides, ex- plosive salts, pyrophoric substances, pemxides, inorganic concenfrared acids, inorganic con- centrated bases, liquid aliphatic bromides. and organic smines.

2. FM each of the classes of chemicals in the problem above. list two examples. 3. The TLV for rrpentane is 1000 ppm. At what temperature will the vapor over liquid pentane equal

this value when in equilibrium? spentane vdmm) Tl°C)

181 0 760 36

Hint: either use the Clausius-Clapeyran equation or a plot of log p vs TIT, yielding a Jtraighl line. Why? Heat of vaporization of sheptane is +6500 cal/mal.

A302 Journal o f Chemical Education

Table 2. Contlnued cability of toxicity and epidemiology data. In addition, calculations involving exposures to several related chemicals and the relationship

4. Combustible limitsfor rrpentaneare horn 1.4to7.4% volume inair. If 100 ml of liquid pemane were of vapor pressure, TWA, and TLV help stn- to evaporate in a closed cabinet having dimensions 1 X 1.5 X 0.5 M, would this be a combustible dents to learn to applv the values in tables, mixture?

5. What orooerties of safew cans make them desirable for disoensers of flammable liauids? ~ ~~~~ . 6 - SI propenes of retr geratorr which arc necessary to a to* storage of flammable War. 7. What are two propen esat llammaoie oqulos wnlch make Inemmoredangerous man sol dmateroals

which are easily burned? 8. Explain the difference between unstable and reactive compounds. What kind of special storage

problems do these compounds pose? 9. Describe differences in the closed cup and open cup test In procedures, results, and applica-

Problems involving storage practices include calculations of the relationshios between ~~ ~

v d p v p w w m and temperature and expo. surr l ~ m m flammal,le limit*, and storage uf clases of chemical materds. I'ruhlrm in - volving chemical storage help students to think in terms of chemical reactivity in con- sidering storage arrangements. The problem

tions. set on energetic chemical systems includes 10. HOW might flash point data be misleading when working with solvents in the presence of liquid calculations of adiabatic flame temperatures

oxygen? of combustion, decomposition energies, and 11. What is the auto-ignition temperature in terms of laboratory systems and precautions? comparisons of energetics of unstable com-

C. ENERGY PROBLEMS pounds. Actual laboratory experiences may be fit

Work out these problems using the data below: into a course of this limited scope with ben- 1. For a mixture of ethene. CpH4, and oxygen (not air): eficial results. Combination of a brief lecture

a) Write a complete, balanced equation far stoichiametric combustion. with such experiences as use of goggles, eye b) Compute the enthalpy change of this reaction at 298.15 K. (Assume product water is in the washes. fire blankets. fire extinrmishers. and .

gasems statel. hrrathlng masks; handing of gas cylinders; C) Compne tne ad~aoatlc flame temperatre of lhis reanion. One memad s lo Lse me Compute testInd ancl (,ther suscrptihle com-

program ' S P E A ~ ( E A ~ Y ' (la to so ve me c ~ o c equal on involved rhen all three terms are p,,,,nds for prrorLdes; t P i t i n E of tumr htx,ds: used. and use of available testing apparatus such as

2. Assume the composition of dry air to be 78 mole % nitrogen. 21 mole % oxygen, and 1 male % explosimeters, ~~i~~~ counters, or mercury aro(m: "l-:FC..-l" -. ~ > , a c , , r t > .

a) Write a camp ete. oalanceo equal on for stofcn omeldc combust.on of ethene n dry aa. There arr man" \,ideotaprs, slide set$, and b) Compute h e enthalpy cnange of lhls reaction at 298 15 1( IAssbme product water lo in the film., courip, .rhpse are - - ~ ~ ~ ~ ~ ~ ~ ~ ~~

gas state). visualize situations or demonstrate tech- C) Compute the adiabatic flame temperature of this reaction. niques for using apparatus. Some, for exam- d) Compare the adiabatic flame temperature of this reaction in pure oxygen to that in air. ple "Mercury Hazards9'and "ABCD's of Fire i ) Why is there a difference? Extinguishers," follow a script to tell a mes-

ii) Discuss the above difference in terms of kinetics, ventilation, special precautions, etc. sage and were photographed by a staff pho- 3. For the dewmposition of 2,4-dinitrophenol. C.H4N$Jqs, and nitromethane. CHsNOs, in the absence toeraoher. Other UICC slide sets are collec-

of air: ti& bf slides of accidents, situations in labs, a) Write a complete, balanced equation for stoichiometric decomposition for each substance. illustrations from books, and other private

Use rules in the article by Stull in Renfrew. Voi. 4, (3L p. 1. sources, many of which may not be dupli- b) Compute the enthalpy change of each reaction at 298.15 K. (Assume product water is in the cated, others are combinations ,,f many types

gaseous state) such as graphs, diagrams, illustrations from C ) Compare AHof decomposition per gram of each of the two compounds. texts, clinical cases, and excerpts from acci-

ESSENTIAL DATA

A. Specific Heat Equation: Cp (calldeg-mol) = a + bT+ c T 2 AH= X p A T

8. Enthalpiss of Formation for Selected Compounds

Enthai~v of Formation.

Compound callmol(298.15 K)

Ethene (g) +12.496 Water (g) -57.798 Carbon dioxide (g) -94.052 Carbon monoxide (g) -26.416 Nitromethane (I) -21,280 2.4dinitraphenol(s) -51.500

C. Specific Heat Equation Constants

Specific Heat Equation Constants

Substance a b c

Water (9) 7.17 Carbon dioxide (g) 10.55 Nitrogen (g) 8.66 Araon la) 4.969

Examples of problems are listed in Table concepts. Toxicology problems involve use of 2. Problem sets are useful for reinforcement safety literature to find toxicity data for a of concepts developed in class discussions. chemical or class of chemicals and are de- Many texts give general information and do signed to familiarize students with standard not go into problem-solving and calculations safety references and to help students make which may help students to understand extrapolations and judge validity and appli-

dent reports. A list of audiovisuals which I found useful can be found in Table 3.

In-deoth articles on various ohases of

on current accidents and explasions, laws and regulations, and techniques.

Additional readina may he assigned in some areas. For exa&ple, a reference on tox- icity of chemicals used in academic labora- tories hv Carter and Fernando (8) is an as-

which everyone should have is in compact form in the ACS booklet: "Safety in the Ac- ademic Chemistrv Laboratories" (9). An ex- cellent referen& book is Bretheriek's "Handbook of Reactive Chemical Hazards" (10) which should he in all libraries.

An assignment, "Preparation for a Haz- ardous Chemical Experiment," is a culmi- nation of most of the topics in the course. Questions in the final examination are based on reading rather than numerical calculations and are similar to those used by Lowrey (4 ) , but oart of it is avisual oerusal of set-uos of hazardous situations in the laboratory or slides of real situations which should be ree- ognized. For example, a set-up for adistilla- tion with obvious hazards such as outdated ether, paper litter, poorly fitting heating mantle, frayed wires, cracked flask, or poorly

(Continued on page A3041

Volume 59 Number 10 October 1982 A303

Table 3. Videotapes, Films, and Slide Sets

Topic Length T Y P Source

Ignorance Isn't Bliss I 0 min V UICC (12, Toxicology 15 mi" S UICC'

Laboratory Hazards and 59 mi" V Geological Survey (13)b Safety Procedures

First Aid for Chemical 15 min S Encon Mfg. Corp. ( 1 4 ) Exposure to the Eyes

ABCD'S of Fire Extinguishers 10 mi" S UICC (12 , The Double Edged Sword 20 min V NIH ( 1 5 ) Fume H w d s 10 mi" V UlCC ( 12, Compressed Gas Cylinders 10 min V UICC ( 12, Mercury Hazards 10 min S UlCC ( 12, Our Hidden Natural Resources 20 min F EPA (16) Flammable Storase Hazards 45 min S UICCd

~hese slides are ol local interest a may not be repmduced. Similar slider m y be obtained w made by anyone to fit with a lecture by copying graphs, textbook illuslrations, or by contact with Dcal =few officiais for pictures of local a* dens. b T h ~ ~ are several short seauencer which are verv useful: Fume Hwds. 7.5 min: Eve Wsrh Stationa. 2.25 mi":

nergency Shower, 2 min; ~ c i d Spill Remactmenf, 4.5 min: and solvent ~ires. 6.25 min. copies of this tape may be mined by sendiqa 60min. 3lCin. blankvideoL%pe cassette w h yourrequest to PhoeDe L Ham U S . Geolqical Swey. 0. Box 25046. MS917. Denver FederaiCenter, Denver. CO 80225.

:cured water hoses may he viewed by the udents with a request that they note as #any hazards as they observe. This work is supported by a National

cience Foundation LOCI grant. I wish to lank the NSF as well as memhen of the hicago industrial community including the hicago Area Technical Council.

iterature Cited

I) National Research Council, "Prudent Practices for Handling Hazardous Chemicals in the Laboratory: National Academy Press, Washington, DC., 1981.

2) Steere. N. V. (Edilar),"Safely in the Chemical Labo- ratory: Journal of Chemical Education. Fdston, PA 1834Z.Vols. 1. 2,and3,1967. 1970. 1914.

1) Renfrew. M. M., (Editor), "Safety in t h e Chemical Lshoratory." Journal of Chemical Eduration, Eeuton, PA 18042. Vol.4, 1981.

1) Lawry, G. G., J. Chom Educ., 55. A235 A263 (1978). i) Green, Michael E., and Turk, Amm, "Safety in

Working with ChemicaLs: MeuniUanPublishing Co., Inc.. New Yurk. 1978.

i) Meyer. Eugene, "Chemistry of Hazardous Mstorials." Prentice Hall, Inc., Englewwd Cliffa, NJ, I977.

(7) Fu8caldo.Anthony A,. Erlieh, Barry J., and Hindmen. Barbara. "Laboratory Safety-Theory and Practice: Academic PIPS. New York, 1980.

(81 Carter, D. E., and Fernand~,Q. ,~~ChemicalT~xi i I~ . Part I. Organic Compounds: J. CHEM. EDUC. 56. 284 (1979): and "Chemical T o x M w . Pan 11. Metal Toxieity"J. CHEM. EDUC.Y.490(19791.

(9) "Safety in the Academic Chemistry Laboratory", 3rd Ed., American Chemical Society. Washington. DC 20036, 1979.

(10) Bretheriek, L. (Editor). "Handbwk of Reactive Chemical Haxards: 3rd Ed., Butterworth's, Lon- dnn~Boston. 1981.

(11) "NIOSHIOSHA Guidelines for Chemical Hauvd."(3 Vol. 1981). Singlo mpiesarefree from NIOSH,Pub- licationa Dissemination, 4676 Columbia Parhay. Cincinnati. OH 45226 Plesseendm aself-addressed mailing label.

(12) Uniueniqv of Illinois at Chicago. Chemistry Depart- ment, 1980.

(13) US Geological Survey, US Depart of the interior, Denver, CO 25046 (1979). See Note Zon Table 3.

(14) The Encon Mfg. Corp.. Houston. TX. (15) Bureau uf Radiological Health, NIH, Rockdle, MD

20&52. (161 Film Comm. 108 W. G r a d Chicago. IL 60610. dis-

Irih,,tnr .. . . . .-. . (17) Cohen,S. andPietar,S., Speakeasy Computing Corp.

Chicago ll9'79).

NIOSH/OSHA HAZARD GUIDES

Information about the health ef- fects of specific chemical substances can he found in the new "NIOSHI OSHA Guidelines for Chemical Haz- ards."

The Guidelines are intended togive people in occupational health pro- grams summary information including technical data on exposure limits, routes and symptoms of exposure, ef- fects of overexposure, medical sur-

veillance, monitoring, toxicology, chemical identification and respira- tory and personal protection equip- ment. Chemists and teachers of chemistry should have easy access to these guidelines.

The three-part work covers the 320 hazardous chemicals regulated by the Occupational Safety and Health Ad- ministration. Single copies are free from NIOSH. Publications Dissemi- i n , 4 6 . l i Parkway, Citainnati. Ohiu 45?26. Plrxvr mcloae a self-addre-sed mailing latwl.

A304 Journal of Chemical Education