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.
