LABORATORY EXPERIMENTS

HOLT PHYSICS Safety in the Physics Laboratory, continued
year; this will allow you to continue to raise the standard of safety in your
classroom. Do not perform any activities in a classroom or laboratory until
you can verify that it is safe and you are prepared to respond to emergency
situations.
Monitoring activities for safety
Once the laboratory is reviewed and all safety issues are corrected, turn your
attention to the activities that will be performed in class. The Invention Labs
in this booklet require careful attention to safety, and all initial plans should
be reviewed for possible safety concerns. Students should not be allowed to
work in the lab until their proposed plans have been reviewed and approved
from a safety standpoint. Every teacher should review all experiments,
demonstrations, and activities for safety concerns before presenting them to
the class. The goal of this review is to identify and eliminate potential safety
hazards. In this way, you can maximize learning while minimizing risk and
be prepared in case a safety issue arises during the activity.
All reviews should be carried out in the following four stages.
1. Identify the risks
Before introducing any activity to the class, analyze the activity, and ask
yourself what could go wrong. Try to consider all possibilities, no matter
how unlikely they may seem. Carefully review the list of materials called for
to make sure they are safe. Inspect the apparatus in your classroom to make
sure they are in good working order. Read the procedures to make sure they
are safe. Record any hazards or concerns you identify in a safety log.
2. Evaluate the risks
The focus of this step is to minimize the risks you identified in the last step
without sacrificing learning. Weigh the pedagogical value of the activity
against the safety risks. Remember that no activity you can perform in the
lab is worth risking injury. Thus, extremely hazardous activities or those that
violate your school’s policies must be eliminated. For activities that present
smaller risks, analyze each risk carefully to determine its likelihood. This can
be difficult because of the scarcity of documented cases of lab accidents.
Using your best judgment and available information, estimate the probability
of occurrence for each risk. If the pedagogical value of the activity does
not outweigh the risks, the activity must be eliminated.
3. Select controls to address risks
Even low-risk activities require controls to eliminate or minimize the risks.
Be careful that in devising controls you do not substitute an equally or more
hazardous alternative. If no reasonable controls can be devised, eliminate the
activity. Some control methods include the following:
HRW material copyrighted under notice appearing earlier in this book.
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HOLT PHYSICS Laboratory Experiments Teacher’s Edition