Electricity powers nearly everything used in the laboratory instructional space and related areas (e.g. preparation room, etc.). Examples of electrically-powered devices include aquariums, hot plates, microwave ovens, centrifuges, refrigerators, incubators, and more. The associated safety hazards should never be overlooked--these and all electrical devices used in the laboratory setting present a potential danger of injury and even death in some cases due to electric shock, electrocution, burns, fires, explosions, and falls. Most incidents are a result of unsafe work practices, improper equipment use, and faulty equipment.

The following information addresses electrical safety protocols for middle and high school science laboratory instructional spaces and related areas which teachers and their students need to be aware of for a safer teaching/learning experience. 

Equipment Inspection & Maintenance

To begin with, all electrical equipment needs to be inspected before using it in a hands-on laboratory activity or demonstration. This includes power supplies, hot places, microscopes, meters, extension cords, etc.  Never use any electrical equipment which is found to have frayed or cracked cords, loose plugs, exposed wires, missing ground prongs, or other issues. It is important to remove defective equipment from service immediately and be sure to tag it with “Do Not Use.”

Outlet and Circuit Safety

Uses of liquids in laboratory instructional spaces requires electrical receptacles to have GFCI-protected outlets. This is not only for water used in faucets, but also wave tanks, aquariums, etc. It is also critical that outlets near sinks and wet areas are covered and compliant with local code. Never overload outlets or run multiple high-draw devices on single circuits. 

Another important electrical issue is the use of extension cords. They are not permitted for permanent setups. Also, use only temporary, heavy-duty cords.  Remember to never daisy-chain extension cords or power strips. Extension cords need to be unplugged from the electrical receptacle end the end of each day, given the potential for overheating and causing fires.

Safer Use of Electrical Devices

When preparing to use electrically powered equipment, remember to turn the equipment OFF before plugging in or unplugging. Also, ensure hands are completely dry. Keep equipment far from sinks, eyewashes, and wet areas. Place cords to avoid tripping hazards.  Use only school-provided, properly rated power supplies for student experiments. Lastly, never modify plugs, cords, or equipment.

Water and Chemical Considerations

Do not allow liquids to accumulate near outlets, cords, or equipment.  Use secondary containment for experiments involving water near electrical devices (e.g., electrophoresis power supplies). Also, be certain to wipe spills immediately and deactivate nearby equipment.

Lockout/Tag-out

If equipment is undergoing maintenance, the teacher needs to disconnect it from electricity via plug or breaker panel. Once that is done, attach a “Out of Service/Do Not Operate” tag. Make sure students never attempt to repair or restart tagged equipment.

Emergency Procedures

Every laboratory instructional space should have a clearly marked electrical shutoff (master kill switch) or accessible breakers. In addition, procedures need to be provided for electrical fire response (use Class C or ABC extinguisher, never water) and electrocution response (cut power FIRST, then assist). Annual practice and teacher-led review of emergency response also need to be provided prior to any laboratory hands-on activities or demonstrations.

Student Behavior Expectations

Students must:

• Never insert objects into outlets.
• Keep metal jewelry away from live circuits.
• Use electricity only as instructed—no “experimentation” with household wiring or unauthorized devices.
• Follow power supply voltage/current limits set by the teacher.
• Maintain dry, uncluttered workstations.

Teacher Responsibilities

Teachers need to provide safety instruction before any hands-on activity or demonstration using electricity. Following the training, they must supervise all electrical experiments directly.  It is also critical that teachers ensure all OSHA and other legal standard electrical codes required by the district are met.  The last thing is to maintain a written inventory of lab electrical equipment, including inspection dates.

Special Equipment Protocols

Different types of electrically powered equipment in the laboratory instructional space require specific or special safety protocols, including the following examples:

1. Microscopes & Microscopes Lights
   1. Ensure cords are insulated and not under mechanical strain.
2. Hot Plates
   1. Use only models with grounded plugs.
   2. Keep flammables far from heating devices.
3. Van de Graaff Generators
   1. Ensure student medical concerns (e.g., implanted devices) are considered.
4. Electrophoresis / Power Supplies
   1. Use low-voltage, current-limited educational units.
   2. Keep lids on gel boxes while energized.

Documentation & Compliance

A high school or middle science lab must have the following documentation relating to electrical safety:

• Electrical safety rules in the Chemical Hygiene Plan.
• Annual inspections by district facilities staff.
• Compliance with:
  • Legal safety standards for electricity use (e.g. OSHA general duty clause)
  • Better professional safety practices for electricity use (e.g. NSTA, ACS, NSELA, etc.)
  • NFPA 70 (National Electrical Code)
  • Local/state building codes
  • NFPA 45 for science labs if adopted by the state/district (primarily ventilation and hazard classification, but indirectly related)

Final Thoughts

Electrical devices are critical in today’s academic and research laboratory instructional spaces.  Equally important is the proper use of these devices in the teaching/learning instructional spaces, based on legal safety standards and better professional safety practices.  Help make all of your hands-on activities and demonstrations safer for you and your students by following the noted recommended safety protocols in this commentary!

Resources

“Electrical Safety in the Laboratory” Written by Ira Wainless, B.Ch.E., PE, CIH’ March 3, 2021 – Lab Manager: https://www.labmanager.com/electrical-safety-in-the-laboratory-25294?_hsenc=p2ANqtz--ujg29o9bteW8cU8_m6augg6avWgqcy0VdxEyc3JmLjj-gnpVFRXfsDFxGXbq8czrgS3yWIMVYa_CBJ7O9rC-bjtJ3-A&_hsmi=377674480

Submit questions regarding health and safety issues in science/STEM instructional spaces to Ken Roy at safersci@gmail.com. Follow Ken Roy on X: @drroysafersci.

The mission of NSTA is to transform science education to benefit all through professional learning, partnerships, and advocacy.