Electrical Safety

1. Preparation for Electrical Hazards

1. Be familiar with the location of the laboratory electric control panel and know how to shut down the power in case of emergency. Locate the circuit breaker box in the laboratory and identify the circuit in which the electrified equipment is plugged into. All circuit breakers should be labeled appropriately, identifying the laboratory area or specific equipment it is associated with.
2. Be familiar with the type and location(s) of fire extinguishers in case of an electrical fire. Electrical fires (also known as Class C fires) require an extinguisher containing carbon dioxide. The location of the fire extinguisher should be marked overhead or with floor signage with arrows pointing to the location. According to OSHA, the 4 key steps for proper use of an extinguisher are³:
   a. Pull the pin.
   b. Aim the nozzle towards the base of the fire.
   c. Squeeze the trigger to control the release of agent.
   d. Sweep from side to side.
3. Inspect all laboratory electrical equipment periodically to ensure that all equipment and its associated internal and peripheral wires are in prime working conditions. If any wires are in poor condition, have them repaired or replaced by a qualified electrician. It may be advantageous to have group members assigned to this task with the results of their investigation provided in a log book associated with the instrument.

2. Avoiding Electric Shock

1. Never touch electronics with wet hands or wet materials.
2. Check that all power cords are in good condition before turning power on. Frayed cords or exposed wires should not be used. Have the cord repaired or replaced by a qualified electrician.
3. Keep wires away from corrosive chemicals and organic solvents to avoid erosion of insulation on wires.
4. Replace damaged or broken sockets, plugs, and joints immediately to avoid further damage. Do not attempt to force a plug into a socket into which it does not fit.
5. Shut down the power and unplug the power cord before opening the cover to any electrical devices. Be aware that some capacitors may still be charged up even hours after removing the cover.
6. Only use equipment with grounding plugs in the lab. The main plugs used for lab equipment include single-phase with safety ground, three-phase with safety ground, single-phase center tapped with safety ground, and three-phase with neutral with safety ground. Do not ever force a plug into a socket. Verify that they are appropriate mates.
7. Never use extension cords for permanent lab equipment except for personal computers or temporary usage. Use surge protectors to protect electrical devices from voltage spikes. Avoid "daisy chaining" of extension cords.
8. Never take the risk of repairing unknown electrical issues. Ask qualified electrical workers to inspect or repair any unknown electrical issues.
9. Never touch a person being electrically shocked because you will act as a conduit for the electricity to reach ground. Call 911 immediately. Ensure your safety first and then shut down the power if possible or use non-conductive material such as wood, glass, or rubber to pull the person away from the electric contact.

3. Avoiding Electrical Fire or Explosion

1. Don't overload a circuit. If a circuit is overloaded, the actual power, current, and voltage might exceed the rated value and lead to a fire. If you are unable to determine the rated values, consult with a person who can determine if the current circuit load exceeds the maximum recommended draws.
2. Store flammable and explosive chemicals away from electric devices. The sparks generated by electric devices might cause fire or an explosion with flammable and explosive chemicals nearby.
3. Make sure all electric devices are away from hot point sources (i.e., an open flame) to prevent melting and electrical fire.
4. In case of electrical fire, first leave the area and call 911 immediately. Pull the most convenient fire alarm and shut down the main power source if safe and possible. Never use water or a conductive foam extinguisher. Use sand or a carbon dioxide extinguisher instead.