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XII. Safety in Elementary School Science This chapter provides information
to assist the elementary school teacher in maintaining a safe classroom environment
for the teaching of science. Safety is an important concern in the elementary
science classroom because students are learning new skills and working with
unfamiliar equipment and materials that can pose some degree of hazard.
Safety in the elementary school science classroom depends on the wise
selection of experiments, materials, resources, and field experiences as well
as consistent adherence to correct and safe techniques. This chapter - a
guide to these safe practices - should be reviewed carefully to avoid
accidents. Safety in the science classroom
requires thorough planning, careful management, and constant monitoring of
student activities. Teachers should be knowledgeable of the properties,
possible hazards, and proper use and disposal of all materials used in the
classroom. This information is available through Materials Safety Data Sheets
(MSDSs). Federal law requires that vendors of laboratory chemicals provide an
MSDS for each substance they sell. The sheets provide detailed information
about the physical and chemical properties, proper storage, disposal,
toxicology, etc., of substances. The law also requires that MSDSs be
available at the worksite. See Appendix C, MSDS: Explanation and
Samples. Science activities are diverse
and often more difficult to supervise than other instructional activities.
Anticipating, recognizing, controlling, and eliminating hazards require
knowledge and understanding of safety issues discussed in this safety manual.
The information provided in the manual is intended to help teachers present
stimulating science lessons in the safest learning environment possible.
Chapter
I: Responsibilities. Safe laboratory program require participation by
administrators, teachers, students and the community. Administrators need to
make available a laboratory area for science activities that is functional
and safe. Teachers need to set a good example by being enthusiastic about
safety. Teachers maintain a safe science program by exercising good judgment,
providing proper instruction and supervision, and maintaining a written
record of safety instruction. Students are expected to follow all safety
procedures and rules in the safety rules agreement that they have signed.
Also, students need to follow all additional instructions their teachers give
them concerning the laboratory exercises they perform. The safety rules
agreement must also be read and signed by parents, thus ensuring that parents
too know and support the goal of safety in the science classroom.
Chapter
II: Legal Aspects of Laboratory Safety. In the event of a charge of
negligence in the science laboratory, several parties are potentially liable:
the state, the school district, the school board, the school administration,
and the teacher. This chapter presents information on the responsibilities
the teacher has as the person immediately in charge of pupils in a science
activity. Among persons potentially liable,
the classroom teacher is most often considered to be placed in the
accountable position. Legal action against a teacher stems from the
presumption that he or she is the expert in the laboratory and, as such, has
the responsibility to ensure that activities are carried out in a prudent and
safe manner. The descriptions of and cautions concerning negligent acts are
clearly outlined.
Chapter
III: Safety Concerns and Emergency Lab Equipment. Classroom size is
a major concern when conducting science activities. There must be a
reasonable amount of space for each student and for emergency equipment and
storage facilities. Proper maintenance of emergency equipment is essential.
Teachers need to know the location and proper use of equipment such as gas
and electric cut-offs, fire extinguishers, fire blankets, and eyewash
fountains or devices. Materials, storage space, and evacuation routes must be
clearly marked. The use of safety goggles is required for many laboratory
exercises. A safety plan and first aid kit
should be in every classroom. Emergency procedures and phone numbers must be
readily available. Teachers should also be aware of the need for special or
more specific safety aids such as spill kits, safety shields, safety showers
and the ability to provide adequate room ventilation during laboratory
activities.
Chapter
IV: Personal Safety Provisions. Providing a safe laboratory
environment involves a combination of many efforts. Chapter IV provides the
information a teacher needs to know about room size, facilities, fire safety,
equipment, and proper ventilation. In addition to proper training,
procedures, ventilation and emergency equipment, it is important to provide
the student with information about personal protection. This information should
include the type of clothing worn, length of hair and jewelry and proper use
of items such as aprons, goggles and gloves.
Chapter
V: Safety Strategies in the Classroom. Safety considerations are essential
when dealing with students and science activities. This chapter provides
information on general and specific safety issues related to science
activities. In planning and setting up student activities, it is essential to
consider safety issues. During the activity, teachers should move about the
room or area where the students are working. They must be familiar with the
materials, equipment and procedures that are part of the activity. Access to
materials and equipment having the potential for harm or misuse (e.g.,
chemicals, heat sources, sharp objects) must be controlled. Students should
be taught safe practices. A teacher's supervision of students requires a
constant alertness to various types of accidents that might occur and the
exercise of common sense.
Chapter
VI: Safe Handling of Equipment. The safe handling and use of
materials and equipment should be foremost in the minds of teachers. This
chapter provides guidelines for the safe handling and use of a variety of
equipment encountered in an educational setting. Teachers and students must
be aware of the potential hazards associated with glass and other sharp
objects, hot materials or objects, ingestion of harmful chemicals, and
electricity.
Chapter
VII: Chemicals: Managing, Handling and Disposing. Ordering, storing,
and disposing of reagent chemicals are important procedures that, when
properly handled, contribute to a safe science laboratory. Therefore, all
teachers of science need to understand these procedures. Chapter VII presents
information about how to order and handle chemicals in ways that help to
maintain a safe science classroom. Chemical safety begins with the teacher
who orders and uses these products. A teacher considering ordering a chemical
for classroom use must understand the relative hazard level of the chemical,
the educational value of using it, their own familiarity with the chemical,
and whether the classroom is adequately equipped for the use of the chemical.
VIII.
Outdoor Safety - Field Studies. Field studies as a means of
experiencing the environment can be a valuable addition to the science
program. The greatest value is realized when educational objectives are
clearly defined and activities are designed to achieve those objectives in a
safe manner. Safety is also achieved when teachers establish and enforce a
set of rules, prepare the site prior to the study, and inform students and
parents of the scope of the study and the environment in which it is to be
conducted. Teachers help ensure safe field activities also when they maintain
up-to-date medical information and emergency phone numbers for all
participants.
IX.
Biology and Environmental Science. Some elementary science activities
are related to biology and environmental science. There are potential hazards
in these areas. Chapter IX contains information on hazards associated with
the handling of micro-organisms and animals, classroom activities on the
school grounds or outdoor study areas, and containment of biological
specimens. The chapter also has information on personal protection devices,
classroom safety, microbiology, zoology, botany, biotechnology and greenhouse
maintenance and operation. Recognition of potential hazards and development
of procedures to avoid or control these hazards are essential for the
completion of safe science activities.
X.
Earth Science. Earth/space science offers many possibilities for rewarding
elementary school science activities. The activities often involve concepts
from chemistry and physics. Chapter X presents information about potential mechanical
hazards (including rockets, wind generating and force measuring devices), electrical,
hazards, chemical hazards (including a list and description of
specific chemicals), light (from the sun, lamps and generated by chemical
reactions), and heat (gas burners, hot plates and candles).
XI.
Physics. Many of the hands-on activities in the elementary science classroom
deal with the science of physics. This chapter presents general and specific
rules for the safe use of materials and equipment that deal with physics.
Topics discussed include hazards associated with mechanical equipment
(falling weights, objects in motion), electricity (burns, shocks), vacuums
and pressures, heat and cryogenics (hot objects, steam, dry ice), certain
chemicals, radiation (lasers, ultraviolet light) and rocketry. 1. Make safety an
integral part of every science activity. In each class preparation,
anticipate potential accidents and problems. 2. Review possible
hazards and safety concerns with students before each activity. 3. Practice the
experiment before presenting it to the class. 4. Keep students on
task and allow ample time for cleanup and waste disposal. 5. Do not allow
eating or drinking during a laboratory exercise. 6. Encourage
students to wash their hands after each science activity. Laboratory chemicals pose a
potential hazard in the elementary science classroom. Most elementary school
teachers are not formally trained in chemistry, yet chemicals are sometimes
used in their science programs. Many laboratory chemicals have common names
that may cause confusion in identifying possible safety hazards. 1. Substances Too
Hazardous for Elementary Schools The
following substances should not be used in the classroom because they present
too great a safety hazard. a. Acids. Acids such as
hydrochloric, sulfuric, or nitric acid should not be used. Even
"dilute" solutions of these acids can cause skin and eye burns. Two
acids generally safe to use are vinegar (weak acetic acid) or a weak citric
acid solution. When working with acids, always wear chemical splash safety
goggles. b. Asbestos. Asbestos should not
be used and should be discarded according to school system policy. Some forms
of this mineral - commonly used in heat-proofing applications - is known to
cause cancer. c. Bases. Sodium hydroxide
(lye) or potassium hydroxide are extremely strong bases. Even dilute
solutions will irritate the skin and, if splashed in the eyes, may cause
injury before one can begin to wash the eye out. For acid-base (pH)
activities, the teacher should consider sodium bicarbonate (baking soda) when
making a basic solution. When working with bases, always wear chemical splash
safety goggles. d. Mercury. Mercury compounds
should not be used in the elementary school classroom. Any thermometers or
other instruments containing mercury have no place in the elementary
classroom and should be properly disposed of. (Mercury thermometers can be
identified by their silver-colored liquid.) When thermometers are needed, use
alcohol-filled thermometers. e. Smoke Generating
Activities. Smoke of any kind affects the lungs because smoke is composed
of particles floating in the air. Any classroom demonstration that produces
smoke should be done in a fume hood, near an exhaust fan, or outdoors with
students upwind. f. Other Chemicals. Teachers should
use only those chemicals that are on the local school system's list of
approved chemicals or those approved by the school system science supervisor.
In using an approved chemical, teachers may obtain technical information on
the chemical from the Material Safety Data Sheet (MSDS) provided by chemical
supply companies. •See
Appendix C: MSDS: Explanation and Samples. 2. Chemical Safety
Practices Using
laboratory chemicals in the elementary science program requires thorough
planning by the teacher. The teacher should be familiar with the intended use
of the substance, how to handle it safely, and what precautions to use with
students. a. Chemical Labeling ·
Label all containers with the substance's common name,
precautions, date, and storage area. For each substance, teachers should have
available the information listed on the MSDS form. ·
Chemicals purchased from major chemical supply companies may
have sufficient information on the label (safety warnings and precautions). ·
Most elementary "kits" use prepackaged and small
amounts of chemicals. These packages may have only the substance name and
weight. ·
Teachers should not set out the entire container of a
material; they should estimate the amount to be used and place it in a
labeled container. ·
After the laboratory activity, the remaining material in the
container should be properly disposed of and not placed back in the stock
bottle. ·
Substances that have no label and are unidentified should be
carefully disposed of in an approved manner. a. Chemical Storage ·
Storage areas and containers should be labeled. ·
Access to these storage areas should be limited so that
students cannot remove substances from them. ·
Laboratory chemicals should be stored in a cool,
well-ventilated room with shelving spacious enough to maintain separation of
incompatible substances. ·
If you use flammable liquids, store them in standard safety
cans placed in a metal cabinet. ·
Store dry chemicals above liquids, and store oxidizers away
from all other chemicals. ·
When transporting chemicals from the storage area to the
classroom, use a cart with shelves that have raised edges. ·
Do not allow children to transport hazardous substances. •See
Chapter VII.A.4, Chemical Storage. b. Additional Safety
Precautions ·
Students should wear chemical splash safety goggles when
working with laboratory chemicals. ·
Students should be instructed not to taste any laboratory
substances and to always wash their hands after use. Provide materials for
washing hands at the conclusion of the activity. ·
Instruct children not to mix substances at random to satisfy
their curiosity. ·
Never pipette by mouth. Always use a pipette aspirator bulb. ·
Be alert to possible hazards presented by chemicals used in an
activity. ·
Keep flammable materials (e.g., cooking oil or paper) away
from flames. ·
Instruct students to smell odors by wafting the odor toward
them with a cupped hand. 1. Fire Types The
potential for fire is ever present in a school. The table below lists the
four classes of fires and methods for extinguishing them:
2. Alcohol Burners Do not use
alcohol burners as they are extremely hazardous. Safer alternatives to
alcohol burners include candles, hot plates (models without exposed coils),
gas burners, or small portable gas cylinders designed for laboratory use. 3. Effective Safety
Practices In case
of a classroom fire, the teacher's first response should be to evacuate the
classroom. The teacher should know the location and how to use the nearest
fire alarm box as well as fire extinguishers, fire blankets, or other fire
fighting aids. The teacher should be ready to react to fires on student's
clothing or hair. If clothing is on fire, roll the child on the floor to
smother the fire. If a fire blanket is quickly available, it should be used.
Water, if immediately available, may be used. Do not direct a carbon dioxide
(CO2) fire extinguisher at an individual because such
extinguishers produce dry ice that can cause frostbite. Periodically check on
the location and condition of fire extinguishers. Students should tie back long,
loose hair, and remove bulky coats that could serve as a potential fire
hazard. 1. Goggles Use
chemical splash safety goggles when engaged in any activities that might pose
a risk of eye injury. Safety goggles should be used when- a. using laboratory
chemicals in an activity. b. using projectiles
or sharp objects. c. flying particles
are likely to be produced (as when solid materials are struck). d. when heating
materials. 2. Group
Demonstrations For group
demonstrations, use a safety shield (clear, impact-resistant plastic) to
provide additional safety. 3. Maryland Law Maryland
law requires that teachers, students, and visitors wear approved and
appropriate chemical splash safety goggles when caustic or explosive
chemicals or hot liquids or solids are in use. (Annotated Code of Maryland.
Education Article, 7-4045). The
following website offers more information on this topic: Elementary
schools may purchase one set of safety goggles to be kept in the school and
shared among all teachers. They would be stored with other science equipment.
The goggles should be cleaned after each use. There are several ways to clean
goggles. If funds allow, an ultraviolet cabinet can be used to store and
sterilize the goggles. Alternatively, single-use alcohol wipes can be used to
clean all surfaces including the strap. Another alternative is to dip the
goggles in a dilute solution of bleach and allow to air dry. •See
Chapter IV.A, Eye Protection Concerns; Chapter VIII.B, At the Site; and
Chapter XII.H.4.r, Animal Hazards - Effective Safety Practices. 4. Eye Safety Planning To
ensure an effective program of eye safety, teachers should- a. establish a plan
for storage, cleaning, and distribution of goggles; b. discuss with
students the need for and appropriate use of safety goggles; c. discuss the need
for eye safety when planning science activities; d. provide eye
protection for everyone performing or observing laboratory activities when
there is a risk of a hazard to the eyes. 1. Hot Plates Hot
plates are one of the most common electrical devices in the laboratory. Hot
plates that have exposed coil wires are not recommended because, when turned
on high, the wires become red hot and can ignite a wide variety of
combustible materials. Only the solid metal or glass-top hot plates with
on/off indicator lights are recommended. Even these types pose risks. a. Hot plates should
be handled with special care since there is no difference in the appearance
of one that is on and one that is off. Even after they have been turned off
for several minutes, they remain hot enough to cause a burn. b. Electrical cords
can fray and crack with age. This condition can lead to electrical short
circuits that can cause burns and/or fires. c. Electrical cords
on the floor or draped across desks create tripping hazards. 2. Batteries Batteries
(dry cells), especially the alkaline variety, can cause burns to the skin
when a wire is placed across both terminals. 3. Effective Safety
Practices a. Electrical
devices used in the laboratory must have a three-prong (grounded) plug. The
third wire grounds the metal housing on the device. If you have to use a plug
adapter, make sure it is properly grounded. b. Electrical plugs
should not be modified in any way. c. Remind students
to remove an electrical plug from a receptacle by pulling the plug, not the
cord. d. Children should
be warned/reminded never to put any object into an electrical outlet.
Teachers may want to cover unused outlets with plastic inserts to safeguard
against this risk. 1. Safety Hazards Substitute
plastic labware for glassware where possible. New plastics like polycarbonate
(Lexan®) have been successfully used for laboratory containers. While not
useful for heating, the plastic is clear and extremely hard and can be used
for almost all water soluble compounds. Beakers, flasks, graduated cylinders,
and thermometers now are available in plastic. Check with your science supply
company. 2. Effective Safety
Practices a. Always inspect
glassware for chips or cracks before and after use. Cracks will eventually
work their way through the glass. Discard any cracked item. b. Glassware that is
to be heated should be made of borosilicate (e.g., Pyrex®). c. Remember that hot
glass and cold glass look exactly the same. d. Never place
heated glass items near students. e. Never place
heated glass items in water. f. Do not use glassware
designed for science experiments as a container for consumable liquids. 1. Safety Hazards Investigations
and experiments outside the classroom are a valuable part of the science
experience for the elementary student. The activity must be well-prepared and
follow an approved plan. 2. Safety Practices See Chapter VIII, Outdoor Safety - Field
Studies. The use of live animals in the
classroom can help students understand and appreciate life processes. Before
bringing animals into the classroom, teachers should check the school or
school system policy. It is important to select animals that are appropriate
to the instructional needs and are practical to maintain. Good safety
procedures should be established for the protection of students from the
hazards of classroom animals as well as to ensure the humane treatment of
animals. The humane treatment of animals
in research and teaching is a sensitive issue. The Council of State Science
Supervisors, the National Association of Biology Teachers, the National
Science Teachers Association, the Humane Society of the United States, the
Animal Welfare Institute, and the National Society for Medical Research all
have established guidelines and position papers supporting the safe and humane
treatment of animals used for the cause of science. The following websites offer more
information on this topic: 1. Types of Hazards Animals
in the classroom can be hazardous in several ways. a. Animals may
contract and serve as carriers for human disease. b. Animal scratches
and bites can be hazardous to humans. c. Animals can be
sources of potentially severe allergies. d. Animals may
adversely affect classroom air quality. 2. Animals Not
Recommended Because
the following animals present a high risk of infection and/or injury to humans,
they should not be kept in the elementary school: a. Any venomous
(poisonous) reptiles b. Venomous fish c. Black widow and
brown recluse spiders d. Scorpions e. Bees, wasps,
hornets, and other stinging insects f. High-risk rabies
carriers: bats, skunks, raccoons, foxes, minks, weasels, ferrets, opossums,
unvaccinated dogs and cats, and other primates (including apes, monkeys,
lemurs, marmosets) g. All wild animals
- dead or alive (except for those that have been properly prepared through
taxidermy or similar professional procedures) h. Any animals that
can cause an allergic reaction to any student. Check with your school
nurse/aide. i. Any insect or
arachnid (ticks, mites, spiders) capable of carrying disease into the
classroom j. Household pets 3. Animals Permitted
with Caution The
following animals may be permitted but with the noted caution: a. Turtles and
snakes: possible salmonella infection b. Fur-bearing
animals: possible cause of allergies and danger of bites c. Tarantulas:
biting d. Parakeets and
parrots: source of psittacosis infection 4. Effective Safety
Practices a. Obtain animals
from a certified disease-free source ( e.g., a qualified animal distributor
or pet shop). b. Use heavy gloves
when handling animals. c. Wash hands and
exposed areas of the body with hot water and soap immediately after handling
or feeding animals and after cleaning cages. Salmonella bacteria are common
to a wide variety of reptiles. d. Avoid
hand-to-mouth contact when handling animals or cages. e. Report any bite,
scratch, or equipment-inflicted injury of a student to the school nurse or
principal at once. f. Rats, rabbits,
hamsters, and mice are best picked up by the scruff of the neck, with the
hand placed under the body for support. g. All mammals used
in the classroom should be inoculated for rabies. h. Make sure guinea pigs,
hamsters, and mice are certified by the vendor as "LCM free." LCM
(lymphocytic choriomeningitis) is an uncommon but potentially serious viral
disease transmitted to humans from these animals. i. Clean and
disinfect cages to ensure dry and odor-free care. j. Obtain fish from
tanks where all occupants appear healthy. k. Make provisions
for animal care over weekends and holidays. l. The animal cage
should be constructed of 1/4 inch wire mesh or smaller. A converted aquarium
with wire mesh top may prove satisfactory. m. Children should
be cautioned never to tease animals or to insert fingers or objects through
wire mesh cages. n. When young are to
be handled, first remove the mother to another cage. o. Dispose of feces
and bedding in a sanitary manner (flush down toilet or seal in plastic bag). p. Do not incubate
chicken eggs for hatching unless you have identified a permanent home for the
chicks. Be prepared to keep the chicks for three weeks after hatching since
Maryland law prohibits giving away or selling chicks less than three weeks
old. q. Do not use any
animal that has been preserved in formaldehyde. Formaldehyde is a known human
carcinogen. When dealing with preserved animals in the classroom, be alert to
the possibility that the animals may be preserved in formaldehyde or other
toxic substances. r. Specimens
preserved in a safe, non-formaldehyde solution should be washed thoroughly
before handling, and students should be instructed to use chemical splash
safety goggles to prevent eye injury. •See
Chapter IX.D.2.c, Other Guidelines for Working with Animals. Plants can be used effectively to
provide a living laboratory for elementary school science instruction. By
providing experiential learning opportunities, science educators can help
students to develop the kind of reasoned thinking that will result in
responsible decision-making regarding human/ecosystem interaction. An example
of this kind of knowledge is the fact that several poisonous plants,
including poison ivy, are also important food for wildlife. 1. Poisonous Plants a. Teachers may want
to confine their lesson on poisonous plants (poison ivy, poison oak or poison
sumac) to pictures. b. Before using an
outdoor learning area, examine the site for the presence of poisonous plants.
When visiting these sites, carefully monitor the children to keep them away
from the poisonous plants. c. Children should
not put any plants in their mouths. 2. Effective Safety
Practices a. Only plants that
are not hazardous to children should be used. b. For classroom study,
only use plants with which you are familiar. c. Treat commercial
seeds with care because they may have been treated with toxic fungicides. d. Caution children
that they should never place any plant or part of a plant in the mouth. e. Make hand washing
routine procedure after any laboratory activity even when working with
plants. J. Additional Safety Precautions 1. Do not use a
thermometer in boiling water unless it is designated for that use. 2. Provide gloves
for anyone handling glass wool or steel wool. 3. Do not use
reflected sunlight for microscope illumination. 4. Caution children
against touching the metal housing of microprojectors as the housing can
become extremely hot. 5. When growing
microorganisms on agar in petri dishes, proper decontamination/sterilization should
be employed before discarding. Once sealed, agar plates should never be
opened to examine. •See
Chapter IX.C, Microbiology, for proper procedures. 6. When using dry
ice, observe these cautions: a. Always handle
with gloves or tongs; dry ice can cause burns. b. Do not allow
carbon dioxide gas given off by dry ice to accumulate in low areas. The gas
is more dense than air and, when it accumulates, can cause asphyxiation. 7. Helium is an
inert gas but, if inhaled, replaces oxygen and can cause asphyxiation. 8. Tincture of
iodine from the drug store is a satisfactory substitute for iodine crystals
for testing for starch. 9. Do not look
directly at ultraviolet lamps as the light is dangerous to the eyes and skin.
10. Use alcohol
thermometers instead of mercury thermometers. Mercury and mercury compounds
are accumulative poisons and should not be used in elementary school. 11. Observe molds in
closed containers. Many varieties produce spores that cause allergic
reactions or are pathogenic to susceptible individuals. 12. It is important
to make the distinction between baking soda and washing soda. Baking soda is
sodium hydrogen carbonate (NaHCO3) and is relatively harmless.
Washing soda (or soda ash) is sodium carbonate (Na2CO3),
a strongly alkaline substance and a strong irritant to the skin and eyes. 13. Caustic soda is
sodium hydroxide (lye-NaOH) and an extremely strong base. A strong irritant
to eyes and skin, it is not recommended for classroom use. |
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