A Safe Science Environment
A safe classroom environment begins at the beginning of the school year, and should be one of the aspects of planning and preparation for the opening of school. Here are some aspects of the environment that you should use as a checklist to determine the safety-worthiness of the the science classroom. Not all science rooms contain labs, so you will find that when a teacher is about to do a lab activity, he or she will make arrangements to use the lab. Therefore, when considering safety, the teacher will need to include all rooms he or she uses for science instruction.
• The school has an automatic sprinkler system.• Each lab has two unobstructed exits.
• Each lab is provided with adequate ventilation, fume hoods, and heat removal systems.
• Safety-glass screens or shields are available at each demonstration table.
• Labs are equipped with readily accessible fire blanket and fire extinguishers.
• Labs are equipped with a readily accessible shower and an eye-wash fountain.
• Each lab has a readily accessible, properly equipped first-aid cabinet.
• Safety goggles are available for each student and teacher for hands on/lab activities.
• Laboratory coats or aprons are provided for each student and teacher.
• All possibly hazardous materials (i.e. chemical reagent bottles) are labeled with
safety precautions and used only under direct supervision.
• Printed, easily accessible instruction for handling laboratory accidents are available and known by the teacher.
• Printed, easily readable safety precautions are posted in each laboratory.
A safe science learning environment occurs when the teacher assumes leadership for the general safety regulations that must be put into place in the classroom. Signs should be posted listing safety precautions, and the rules of behavior while doing science lab activities. The teacher should describe an safety issues related to the activity, e.g. handling of glass, or chemicals, or biological materials.
The first time that a hands on activity or a laboratory experiment is conducted, the teacher should point out and show how the following safety equipment should be properly used.
• fire blanket • laboratory gloves
• eyewash facilities • laboratory aprons
General classroom safety can be accomplished by integrating safety rules into your lesson plans. If, for example, you are dissecting fruit, reinforce the safety rule that no items in the science classroom can be tasted. Here are some general safety rules that you might post on a large sign in place easily read by the students:
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General Safety Rules 1. Wear safety goggles when doing hands on laboratory activities. |
Chemical Safety
The use of chemicals in the science classroom requires knowledge of the potential danger associated with any chemical. The Occupational Safety and Health Administration (OSHA), and the Environmental Protection Agency (EPA) has produced guidelines and recommended lists of chemicals that should not be used in middle and high school science classrooms. In this section we will consider, two aspects of chemical safety: rules for chemical usage, and assessment and storage of chemicals.
Rules for chemical usage. Regardless of the chemical, it should be treated as potentially hazardous, and the teacher should always alert students to this notion. Students should be instructed to handle all chemicals with care. The following rules, suggested in the use of ChemCom, a high school chemistry program outline an approach to chemical safety.
1. Perform lab work only when your teacher is present.2. Always read and think about each laboratory procedure before starting.
3. Know the locations of all safety equipment, e.g. safety shower, eye wash, first-aid kit, fire extinguisher, and blanket.
4. Wear a lab coat or apron and protective glasses or goggles for all lab work. Wear shoes (rather than sandals) and tie back loose hair.
5. Keep the lab table clear of all materials not essential to the lab activity.
6. Check chemical labels twice to make sure you have the correct substance.
7. Do not return excess material to it its original container unless authorized by the teacher.
8. Avoid unnecessary movement and talk in the lab.
9. Never taste laboratory materials. If you are instructed to smell something, do so by fanning some of the vapor toward your nose. Do not place your nose near the opening of the container.
10. Never look directly down into a test tube; view the contents from the side. Never point the open end of the test tube toward yourself or your neighbor.
11. Any lab accident should immediately be reported to the teacher.
12. In case of a chemical spill on your skin or clothing rise the affected area with plenty of water. If the eyes are affected water-washing must begin immediately for 10 to 15 minutes or until professional assistance is obtained.
13. When discarding used chemicals, carefully follow the instruction provided.
14. Return equipment, chemicals, aprons, and protective glasses to their designated locations.
15. Before leaving the laboratory, ensure that gas lines and water faucets are shut off.
16. If in doubt, ask!
Audio-visual programs are available from some suppliers in the form of filmstrips and videos that demonstrate and discuss safety issues in the science class. A-V materials such as these can be used to teach specific lessons on safety (Also refer to the Curry College Safety Program).
Assessment and Storage of Chemicals. Chemical safety is dependent upon the teacher's knowledge of the chemicals used in lab activities. Suppliers of chemicals have devised various systems to inform purchasers of chemicals about the nature of the chemicals and how to store them.
For example Fisher Scientific has devised a chemical safety and alert system that includes
• safety symbols (which can be used with the students)• chemical storage codes
• National Fire Protection Association (NFPA) diamond hazard code.
For each chemical, information is provided which immediately informs the teacher about the hazards associated with the item, how and where it should be stored, and what precautions should be taken when using the chemical
The safety codes identify the equipment and gear that need to be worn when handling a specific chemical. The teacher is informed and warned whether goggles, gloves, an apron, or a hood are needed with each chemical.
The NFPA hazard codes rates hazards numerically inside a diamond on a scale of 0-4. In practice, the diamond shows a red segment (flammability), a blue segment (health, i.e., toxicity), and a yellow one (reactivity). The fourth segment is left blank. It's reserved for special warnings, such as radioactivity or hazardous when in contact with moisture.
The numerical ratings are:
4 = extreme hazard 1 = slight hazard3 = severe hazard 0 = according to present data: none
2 = moderate hazard
NFPA Hazard
Codes A rating of 4 (most severe
hazard) indicates that goggles, gloves, protective clothing
and fume hood should be used. A rating of 0 (no special
hazard) may safely be handled and used in the lab with no
special protection required other than safety
glasses. Storage of chemicals should
not be done alphabetically (as some schools do). They should
be organized according to a classification system designated
the U.S. Department of Transportation (D.O.T.). Materials
are rated as: • Reactive and
oxidizing: (may react violently with air, water or
other substances. Store away from flammable and
combustible materials.) • Health hazard
(toxic if inhaled, ingested, or absorbed through
skin. Store in secure area.) • No more than
moderate hazard. May stored in general chemical
category. • Exceptions:
Some reagents may be incompatible with other reagents of
same category, and must be
stored separately.
•
Flammable: (store in areas segregated for
flammable reagents)
These ratings can be used to organize a storage plan for the chemical stock room. Figure 10.28 shows a graphic depiction of the relative amounts of chemicals in each of the chemical groups in the average high school chemical storage area. This plan can be helpful in organizing a schools storage room. Oxidizers must be isolated from flammables, and all flammables should be stored in a dedicated Flammable Storage Cabinet. If highly toxic chemicals or poisons are part of the inventory, they should receive special security. In general, chemicals should not be stored on the floor, or above eye level. Finally, the chemical storage room should be locked.
Living Organisms in the Classroom
Living organisms should be part of life science programs at the middle and high school levels. The inclusion of living organisms also results in a number of safety and humane issues that the science teacher needs to deal with. According to study done by Mayer and Hinton, the most common use of animals in the classroom is for dissection. In fact they reported that the higher the grade level, the greater the chance the teacher included dissection. For instance, they indicated that 74 percent of the middle school teachers and 94 percent of the high school teaches had their students dissect at least one animal.
They reported that the use of live animals in the classroom showed the opposite trend. Sixty-seven percent of the elementary teachers used live animals in the classroom, whereas 43 percent of the middle school teachers used them, and 54 percent of the high school teachers used live animals.
If live animals such as rabbits, guinea pigs, hamsters, gerbils, mice and rats are used in the classroom they should be handled carefully with gloves. Teachers should not bring wild animals into the classroom since the likely hood of zoonotic diseases is high.
Figure 10.3 outlines the requirements for various animals that teachers might keep in the classroom. It is of the utmost concern that all animals in the classroom be treated in the most humane manner as possible. In general animals should be used for behavioral studies, not for invasive studies. In such cases, bacteria, protozoans, and insects can be used to achieve these objectives.
Requirements
for Various Animals Animal dissection should be
done with the utmost care, and after careful consideration
of goals and objectives. Mayer and Hinton suggest that the
teacher consider the following question before choosing to
do a dissection activity with his or her students 2. How does the use of
dissection support these goals? 3. Should live dissections
be used? 4. How many dissections are
necessary? 5. Can this number be
reduced by using videotapes or demonstrations? 6. Can items from the
supermarket that are "past their prime" be
substituted? 7. Are there alternatives
such as computer programs and videodisc programs that
would be as effective or more effective in reaching your
goals?
1. What are the goals
and objectives in the course you are teaching?
Care must be taken when students do dissections. Only clean and sterilized instruments should be used, and the students should be warned about cutting themselves using the equipment. Students should thoroughly wash their hands after dissections.
Teachers should be aware of the regulations of the state in which they teach with regard to the use of animals in the classroom. The teacher needs to not only protect the students from potential diseases, but protect him or herself from violating state regulations.