edited by
MALCOLM M. RENFREW University of Idaho MOSCOW,
ldaho 83843
A Fire Fighting Experience as a Laboratory Experiment Antony C. Wilbraham Southern lllinois University, Edwardsville, Illinois 62026
It iiruirc>mnryin mnny mritutions at rhc t,cginning i r f ihe fre5hman year fur studrnts raking rhcmi.try uwrrses to he wrn tnlkcnnd shown films concerning laboratory safety practices. Students are informed of emergency procedures and are asked to note the locations of the various emergency systems such as fire e x t i n ~ i s h e r s ,fire blankets, showers, eye baths, ventilation cut-off switches, and emergency telephones. The customary theoretical explanation of how t o extinguish a fire and use appropriate equipment is, however, of limited use in a safety program.
Antony Wilhraham was horn in Chester, England, in 19:36, and received his undergraduate education a t Liverpool Regional College. He holds the Research Diploma of the Royal Institute of Chemistry, London with a specialization in Radiation Chemistry. He is alsoaFellow of that Institute. In 1966 he did postdoctoral work a t the University of South Florida, Tampa, and during the 1967-68 academic year was a visiting Assistant Professor of Chemistry a t Eckerd College, St. Petersburg, Florida. He joined the faculty a t Southern Illinois University a t Edwardsville in 1968 where he now holds the rank of Associate Professor of Chemistry. Over the years his interests have changed from radiation chemistry to analytical chemistry and from there to biochemistry.
Prompted by the growing concern for improvements in safety, as expressed by the Occupational Safety and Health Act (OSHA), I realized that many of our students and faculty (a) had not seen a fire fighting demonstration and (b) had not handled a fire extinguisher in a real or simulated accident. Adootine" the attitude that the first time a nersnn is cnlled umn to use a fire extinrmisher r~~ in an rmrrgrnr). riruaricm shuuld n . br ~ the iirct rime that that indiridunl hw handlrd nn extinguisher, I developed the following program of instruction.
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The basic problem was to design a program which would enable each student to experience putting out a fire. Our resultant program, now in use over the past two years, has involved the participation of over 300 fieshmen chemistry students, more than 200 nursing students enrolled in chemistry courses, the chemistry faculty, the graduate students, and the laboratory personnel. Groups of 24 students practiced in the laboratory and groups of 24-50 students participated in the fire fighting exercises held outdoors: the sessions normally have beencompleted within 2 to 2% hours during regular laboratory hours in the first week of the quarter. (Continued on page A406)
Volume 55, Number 11, November 1978 1 A405
Safety
vapor burns under control a t the container outlet. This demonstrates vividly that safety cans not only reduce the risk of explosions during a fire but help t o control its spread.
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This program, which has been received with enthusiasm and interest by all the participants, starts in the laboratory. Students are given a talk on gcnrrnl Inhumtory safety proceduresand are*hwn the iafetv film "26 Crams of Prrventron." 1 This ha* bren iollowed hv another talk on some soecificsof fire f~ghtinggiven 11sthe Cnivrrsity Safety C c r . mlinacur. The faculty or trarhmg nsriitantb deliver this infurmation after receiving appropriate instructipn.
Since the fire fighting equipment available in the freshman laboratories is usually the carbon dioxide (Con) extinguisher, a demonstration is given of the handling and use of the COa extinguisher. A blast of carhon dioxide from an extinguisher is delivered to a n open floor space in the laboratory; no actual fire is involved. Each student participating in the program is then directed to go through the same procedures that have been demonstrated and t o give a short (2-3 sec) burst of COz from the extinguisher. This operation serves several purposes: i t acquaints the students with the weight of the fire fighting equipment and allows them to experience the ease, or difficulty, of handling a n extinguisher, removing the horn, and operating the lever. The horn and pin are then replaced, and the neat student repeats the procedure. This operation is performed by all the participating students. Several students can use one extinguisher before its charge is exhausted thus keeping costs to a minimum. This first part of the program requires about 1 hour t o complete for a class of 24 students. The second part of the program, extinguishing a contained gasoline fire with a d r y oowder extineuisher.. is oerfarmed outside the building. Vnrmus types and sire. of rxtingtmhers-dry p w d e r , CO,, and wnterare dlsplnved so that rtudcnts may identify them. After some introductory comments on the danger associated with containers exploding in a fire the demonstration starts. Two l-gal metal cans, one containing water and the other containing gasoline, are sealed with press-fitting lids (NOT SCREW-ON TOPS) and placed on a 2 X 3-ft metal tray; alongside them is placed a metal safety can also containing gasoline. (A safety can is a specially designed metal solvent container with a gauze flash protector used for transporting and storing medium sized volumes of flammable liquids.) Gasoline is poured into the trav and ienited. The result is dramatic. .Attrr s m t r d seimds cvplorions occur, the lids of the onc-ynllm rana a r t hurled skyuardi, and the fire spreads mc,menrsrily. The safety can does not explode; the gasoline
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'The film "28 Grams of Prevention" is available on free loan from Safety Film, Fisher Scientific Company, 711 Forbes Drive, Pittsburgh, Pennsylvania 15219. A406 I Journal of Chemical Education
After a few minutes the flames are extinguished with a dry powder extinguisher, the correct use being explained. A water extinguisher is then used to cool the hot metal tray before any more gasoline is added. I t is explained that a dry powder extinguisher, although putting out the fire, still leaves a potential danger behind: it does not cool the area. Water is an effective agent for lowering the temperature of combustible materials below the ignition point, thus preventing reignition. The containers are removed, and a fresh quantity of gasoline is poured inu, the moled melal tray and ~gnitPd.Each student, in turn, is instructed to pick up a powder extinguisher, activate the eapellant gas cylinder (or simply go through the motions of the procedure if the cylinder had already been activated), hold the extinguisher correctly, and advance towards the fire, directing the powder a t the fire as demonstrated earlier. After extinguishing the fire the student reassembles the equipment. Then the fire is reignited. The fire fighting part of the program requires about 1 hour for a class of 24 students. This activity has convinced our participants of the need for hands-on experience. In many instances students are surprised that they were not able to extinguish the fire either because their technique is poor or because thev have used a oartiallv discharged extinguisher. Othrr studenf
