edited by MIRIAMC. NAGEL Ayon High Schaol Avon. CT 06001
An Innovative Course in Lab Safety Miriam C. Nagel Avon High School. Avon, CT 06001
In February, 1980,Fred M. Dewey, Professor of Chemistry a t Metropolitan State College in Denver, presented a paper titled, "Science Lab Safety-A Course for Secondary Teachers," to the Colorado Science Teachers Association Convention a t Colorado Springs. Excerpts from Professor Dewey's paper, which follow, will provide readers of Safety Tips with ideas for similar programs. In his introduction, Professor Dewey said, "The principal objective of the course was to provide teachers with the background necessary to implement an effective safety program for their science lahs . . .To he convenient for teachers, the course was offered in June during the first two weeks of the summer session. The class met daily for three hours for two semester hours credit." Lectures, demonstrations, group discussions, slides, films, videotapes and guest speakers were utilized in the course. The assigned text was "Safety in Working with Chemicals."' Reference materials were available to students on a loan basis. At the first meeting of the class, a course outline was distributed. The objectives of the course were discussed and members of the class were asked to complete a two-part safety questionnaire. Part 1covered their teaching experience, attitudes, and practices regarding lab safety. Part 2 dealt with accidents they had encountered during the preceding academic year. A safety film2 emphasizing accident prevention was shown and discussed. Accident causation and control was the fust area of concern listed in the course outline. Injury factors, basic causes of accidents and application of the principles of control to science lab safety were discussed. The next two subjects to he investigated were responsibility for safety and the teacher's personal liability. "Responsihilities of administrators, teachers, and students were presented, and possible action for the correction of deficiencies was discussed. . . Recommendations were made to the class for reducing the risk of personal liability (for students' injuries)." Since liability laws vary from state to state, the best available local legal advice should he sought in any presentation of this important topic. A discussion of safety rules for the laboratory "included good rules, poor rules, and enforcement. Each member of the class drafted safety rules to be used in his or her own laboratory." In the section on lahoratory design, "the floor plan, essential safety equipment, exhaust hoods, the chemical storeroom, ventilation, special facilities, and egress were covered. The discussion of protective equipment focussed upon eye protection, and a film3 was shown which dramatically illustrated the need for safety glasses and face shields." The proper use of exhaust hoods, safety showers, eye-wash fountains, and fue extinguishers was shown by ~ i d e o t a p eA. ~ local instructor in fire science presented the section on fire safety and fire protection. "A thorough discussion included the NFPA hazard classification system, classes of fires, and the use of the various types of fire extinguishers." "The section on chemical hazards stressed the need to he informed about the properties of the chemicals being wed and safe procedures for handling them.. . . Many chemicals commonly used in science lahoratories were discussed individually!' Attention was given to modes of entry into the body
of toxic chemicals and their acute or chronic toxicity. Incompatibility of chemicals, explosion and fire hazards, safe storage and waste disposal were also stressed. Hazards in life science lahoratories were next investigated. "The unit on lahoratory equipment focussed on equipment commonly used in school laboratories and briefly reviewed less commonly used types of equipment. Safety precautions in handling mercury (manometers, oven thermometers, etc.) were emphasized, as was the hazard of a conventional refrigerator in the science lahoratory." Potential problems and the proper use of electrical equipment and ovens were noted. Gas cylinders, Dewar flasks, heat sources, and cryogenicsrounded out the discussion. "In the section on lahoratory operations.. . criteria were presented for the selection of lahoratory experiments." Professor Dewey, in a personal letter dated October 16, 1981, expanded on the selection process for readers of Safety Tips. He wrote, "In desienine a lshoratorv ~, course. an instructor must consider his ohjectivcs fur the course in deriding what erpcrimenlb to select. I n broad tcrms, hisihjwtivemight ~ncludrilluvtralionoffundamental chemical princ~plea,develr,pmenr o f wientilic thinking, methods uf measurement and other fundamental lahoratory operations, and application of these in doing what a real chemist does (synthesis, analysis, chemical processes, etc.). Exoeriments are examined which mav he the means to accomplish;ni: the uhjectivw o i the course. The bossihle hazards associated with the experiments we evaluated along with the pedaglgkal value otthe experiments. The brncfirs arc weighed wnh the risks, and cxperiments are selected.An underlying premise in the selection process is that a risk-free laboratory is neither possible to attain, nor desirable in an educational setting. Potentially harzardous lahoratory experiments or operations include the followins: I'repamtmt nnd propertlet of hydrogen Crneratmn o f o y ~ e nfnrm putasslum chlorate Properties of sulfur dioxide Preparation of nitrobenzene Use of hydrogen sulfide in precipitation reactions Qualitative analysis-contact with a variety of toxic substances (e.g.,PhCrOa and NiS are carcinogens) Use of dichromate cleaning soltuion." ~~
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Finally, the class was divided into small groups and each teacher, in consultation with the group, drafted a proposal for implementing or improving the laboratory safety program at his or her school. Course evaluations, assigned a t the beginning of the course, were completed. In summing up his presentation to the Colorado Science Teachers ~ssociatiouconvention, Professor Dewey said, Due to the broad scope of activity in school science lahoratories, it is very difficult for a teacher to he current with all safe lahoratory practices. This course provided a structured forum for exchange of information reeardine safetv and health in science lahoratories. and pnwided opp&tunity fur &huol G-ncc renrhers to plan n s&ty program fur t l e i r school laboratory. Course evaluatiom from the class indmted that the course ul~jectiveswore effrctivrlyachieved.
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Green, M. E., and Turk, A,, "Safety in Working with Chemicals." Macmillan. New York. 1978. "28 Grams of Prevention," Fisher Scientific Co., 71 1 Forbes Avenue, Pittsburgh, PA 15219. "Eye and Face Protection fw the Chemical Lahatoy." Your state or regional branch of The National Society to Prevent Blindness. 79 Madison Avenue, New York. NY, 10016. "Laboratory Hazards and Safety Procedures in the Geologic Environment." U. S. Geological Survey,Denver Federal Center, Denver, CO 80225.1979. Volume 59
Number 9 September 1982
791
