2 YC, joule/
edited by ELLENand JAYBARDOLE Vincennes Univemily Vincennes, IN 47519
The Role of Chemistry in Firefighting Emanuel G. Terezakis Community College of Rhode Island, Warwick, RI 02886 The Community College of Rhode Island Fire Science program has been in existence for several years. The state of Rhode Island has instituted an incentive pay program by which firefighters can upgrade their salary level by earning college credits and ultimately hy earning an AS degree in Fire Science. Some general courses are required among which are Chemistry of the Environment and Chemistry of Hazardous Materials. The chemistry courses are included because it is becoming increasingly important for firefighters to he able to respond to fires involving chemicals and exotic materials not easily handled by conventional means. Two chemistry courses are given in sequence because firefighters usually have a total lack of any chemistry background, They need some fundamentals before they can he taught the actual hazards of chemicals. Chemistry of the Environment is a laboratory course originally intended to satisfy the science requirements of nonscience majors. The course now acts as a background to Chemistry of Hazardous Materials by familiarizing the student with basic chemistry and with some of the prohlems created by the chemical industry. Chemistry of Hazardous Materials starts out with a detailed presentation of nomenclature and the classification of chemical compounds. The main thrust of Hazardous Materials is to give the student sufficient chemical background so that he can approach chemical fires more intelligently and effectively. The student is taught the hehavior of chemicals and some elementary information on the toxicity of chemicals. He is also taught the reasons for the various specialized extinguishing techniques that have been developed. Firemen usually are quite familiar with these methods hut have little theoretical backeround to . iustifv . them. There is no lahoratow period in the course, hut there are demonstrations nearly every week which show various combustion-related phenomena. Subject matter begins with some basic concepts such as the gas laws and the way that heat can he transferred from one place to another. Some information is given on proper handling and storage of chemicals. After the introductory topics the course is divided into several segments dealing with specific types of hazards. The chemical properties of several elements, those that are likely to be encountered in afire station, are discussed. This includes the properties of gaseous hydrogen, gaseous and liquid oxygen, sulfur, phosphorus, fluorine, chlorine, and bromine. Chlorine is of particular importance here because of its wide use in treating sewage and drinking water. Corrosive materials such as the common industrial acids are next. The role of some of these in starting fires and their Presented to a General Session of the Sixty-NinthTwo-Year College Chemistry Conference.Community College of Rhode Island. Warwick. Rhode island. November 8, 1980 698
Journal of Chemical Education
interactions with water are stressed. Nomenclature is particularly important here because of the need for speedy and accurate identification of these compounds. Water reactive materials such as sodium.. notassium. and . magnesium metals are studied. Many powdered metals such as zinc and aluminum are also hazardous and their hehavior in a fire and toward water are covered in detail. A section on toxic gases such as CO, HCN, SO2 and the oxides of nitrogen is taught. These are among the so-called fire gases and may be encountered as oart of the atmosohere around hurninn materials. They are;esponsihle for many cases of lung injur; amone firemen. Oxidizine materials are covered because of I~I. Everyone knuws the hnurds oi naturtd :R. ~11111~ : I + ) . I lmt 111thrwnrd. $ r i c w ~ a nmnrrriill ~< s i.11 hey01111 1ha1. IJli#:tiin and resins may n i t appear to he important enough to study. Everyone knows that they burn and they can he extinguished with water. Their hazards go far beyond simple combustion, however; the products of their combustion and pyrolysis are often deadly. These products include most of the fire gases mentioned previously. As an additional hazard, polyvinyl chloride (PVC) when heated to its char point gives off copious amounts of hydrogen chloride gas. PVC's have been implicated in many cases of permanent lung damage and death to firemen who attempted to fight fires without proper breathing orotection. I encountered obstacles in teaching chemistry to a group with no inherent interest in the field. It had become a tradition
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putting off a trip to the dentist. When thinking about the problem I hegan to realize that I was actually dealing with a huge pool ofpractical hazardous
2YC3 Joules is a column to keep persons concerned with teaching chemistry at the freshman and sophomore levels aware of innovations and activily in lower division chemistry courses.The column will include papers from Regional 2YCs meetings. Ellen Bardole has an Associate Dearee from Vincennes Universiw
Year College. Jay Bardole has a BA fromGrinnel1 College andan MA from DePauw
Uni~ersity.He has taught fineen years at Vincennes Universily and is currently Chairman of Chemistry. He has been Secrefary of COCTYC for three years.
chemical experience. Almost everyone had fought a fire involving some chemical substance, either magnesium metal, a hydrocarhon solvent, polyvinyl chloride, natural gas, electroplating chemicals, etc. They had all been given procedures and methods for dealing with these situations but had no theoretical knowledge with which to generalize and make decisions in emergencies that differed slightly from the unes that thev had been told about. I decihed to tap this reservoir of practical knowledge by inviting each student to share with the class some past or recent experience with a chemical hazard. I received an enthusiastic response and much interest was generated. The students in one section did not appear to be very interested in the details of CO-poisoning until one of them suffered carbon monoxide poisoning in a VFW hall fire. The ceiling of the building had collapsed, trapping several firefighters inside and my student and several others attempted to rescue the men without first putting on breathing protection. They were overcome by CO gas and treated in the hospital. The student's doctor explained what had happened to him and explained the symptoms, headaches, and red skin colur-
ation that he was experiencing. (The red skin color results because the Hb-CO complex is much more intensely colored than the normal Hh-02 complex.) The student reported this to the class with great enthusiasm, and I was able to complete the discussion of CO poisoning satisfied that the class had learned something. Another example occurred after we had discussed the proper techniques for extinguishing a magnesium fire. Water and C09 are not indicated for use on hurnine..Me.. because thev increase the rate of comhustion. One student told the story of a magnesium engine block that could not be extinguished by water or foam spray. It almost burned through a flat bed truck used to carrv it awav from the crash scene. It was huried in a landfill and when it was dug up two days later, it burst into flame aeain. I also found it useful to include handouts from medical journals as well as firefighting publications on the hazards to firemen from burning chemicals. I did not compromise my teaching of chemistry theory but managed to make the course more relevant to the students' job a n d personal experiences.
Volume 58
Number 9
September 1981
699
