EARTH/SPACE SCIENCE SAFETY CONCERN
Supplies and Equipment
Earth science laboratory experiences make use of a variety of supplies and equipment that have safety considerations. A review of the safety resources placed in the school learning resource center (LRC) will provide the needed details.
Some special concerns for earth science teachers are:
. chemical storage and theft
. crystal growing chemicals
. eclipse viewing
. eye protection
. flame or borax bead tests
. gas burners and hot plates
. glassware
. lapidary work
. mercury thermometers
. model rocket demonstrations
. rock and mineral toxicity
. spectrum tubes
. volcano demonstrations
All chemicals must be stored in locked cabinets and in small quantities only. MSDS sheets must be on file in the storage room and the main office for each chemical. Care should be exercised to insure that no chemicals are removed from the classroom. Under no circumstances should chemicals or equipment ever be given to students for use at home. Do not accept donations of chemicals or equipment without approval of administrative personnel. Some agencies use schools as �dumping grounds� to rid themselves of liability. This practice can increase the hazards for school personnel and students and increase disposal costs.
The following crystal growing chemicals are safe to use as demonstrations in the classroom: aluminum potassium sulfate, potassium sodium tartrate, sodium chloride and sucrose. Dispose of these solutions in sink drains.
Never allow students to look at the sun directly or with any optical devices (sunglasses, magnifying lens, telescopes, etc.). For eclipse viewing, require that students only use the pinhole method where the sun's image is focused by a pinhole in a sheet of paper onto another sheet of paper. Any other method can cause permanent eye damage.
Supplies and Equipment (continued)
State law requires that goggles must be worn by all students if there is an activity occurring in the classroom that poses an eye hazard. For example, use this protection when mixing chemicals, boiling liquids, working with lab burners, etc. OSHA approved goggles (ANSI Z87) may be purchased from the Akron Public Schools Warehouse. See the school secretary for ordering details.
Students making use of flame or borax bead tests for rock and mineral identification must use eye protection and extreme care with an open flame. In addition, care must be exercised to avoid the inhalation of vapors.
Portable propane burners are not permitted and great care should be exercised when using natural gas burners or electric hot plates to heat any materials. If students are involved in these activities, they must wear eye protection.
Inspect glassware before use. Discard all glassware found to be chipped or cracked. Use eye protection when heating, mixing, reacting or transferring chemicals in any glassware. Use MSDS for safety procedures. Carefully instruct students about the safety considerations involved in the bending and use of glass tubing. Only Pyrex or Kimax brand glassware should be used for heating or reacting chemicals.
Treat all rock grinding and tumbling equipment as hazardous. Lapidary work always requires eye protection and body covering (aprons). Students with long hair need to have it tied back; long sleeves need to be rolled up; loose fitting or bulky clothing needs to be avoided; necklaces and rings need to be removed. Constant supervision of student work and the work area is mandatory.
Mercury is an insidious chemical hazard by skin absorption and inhalation. The vapor produces a long-term contamination that is especially harmful to the teacher.
Whenever possible, use non-mercury thermometers and learn how to clean up mercury spills. (For clean-up details, see Flinn [1998] pp 127-128). Do not use mercury thermometers in swinging holders to measure humidity.
Supplies and Equipment (continued)
Model rocket launches add realism to the earth science class. All model rocket programs must conform with the National Association of Rocketry (NAR) safety code. A copy of this code can be found in the safety resources in Virkus (1978) pp 95-96. Use only commercially produced rocket engines. Never produce or experiment with "home-made" engines.
While rock and mineral identification is a safe and educationally valuable activity, care should be exercised in the following areas: never break rock or mineral samples without proper eye protection; never make use of asbestos samples; use only very dilute hydrochloric acid (0.1M) in small dropping bottles; caution students about the hazards associated with lead poisoning; always require students to wash hands after handling rock and mineral samples; demonstrations of burning coal should be avoided.
The power supplies needed to operate spectrum tubes carry dangerously high voltages and the connections are often exposed. Instructions to students are necessary to avoid electrical shock. Ultraviolet light sources produce potentially harmful radiation to the eye and exposure time should be limited.
Demonstrations of volcanic eruptions using ammonium dichromate should never be
attempted in the classroom. Many chromium compounds are suspected carcinogens.
General Safety
. Science classroom safety is a matter of preparation and consideration. Carefully weigh the risks of any activity against its educational value.
. Understand the potential hazards of any experiment or activity.
. Avoid the idea that "If I only do it once, nothing will happen."
. Complete a Preliminary Accident Investigation Report (GH-20) for any injury that occurs in the classroom. (See the Appendix for a copy of this form.)
. MSDS on file for all chemicals.
. Avoid activities that are beyond capabilities of students.
. Become a model of good science safety for our students.
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