The major hazards associated with electricity are electrical shock and fire. Electrical shock occurs when the body becomes part of the electric circuit, either when an individual comes in contact with both wires of an electrical circuit, one wire of an energized circuit and the ground, or a metallic part that has become energized by contact with an electrical conductor.

The severity and effects of an electrical shock depend on a number of factors, such as the pathway through the body, the amount of current, the length of time of the exposure, and whether the skin is wet or dry. Water is a great conductor of electricity, allowing current to flow more easily in wet conditions and through wet skin. The effect of the shock may range from a slight tingle to severe burns to cardiac arrest. The chart below shows the general relationship between the degree of injury and amount of current for a 60-cycle hand-to-foot path of one second's duration of shock. While reading this chart, keep in mind that most electrical circuits can provide, under normal conditions, up to 20,000 milliamperes of current flow.

In addition to the electrical shock hazards, sparks from electrical equipment can serve as an ignition source for flammable or explosive vapors.

Even loss of electrical power can result in extremely hazardous situations. Flammable or toxic vapors may be released as a chemical warms when a refrigerator or freezer fails. Fume hoods may cease to operate, allowing vapors to be released into the laboratory. If magnetic or mechanical stirrers fail to operate, safe mixing of reagents may be compromised.

Avoiding Electrical Hazards

• All equipment should be inspected before use.
• Make sure that all electrical cords are in good condition.
• All electrical outlets should be grounded and should accommodate a 3-pronged plug. Never remove the grounding prong or use an adapter to bypass the grounding on an electrical cord.
• All electrical outlets within 6 feet of a water source (sink, eyewash, etc.) must be equipped with a Ground Fault Circuit Interrupter (GFC) either on the outlet, or somewhere on the electrical line. Note- the GFC may be located at the circuit breaker box. All GFC outlets/ GFC equipped lines shall be clearly labeled.
• All electrical equipment must have 3 prong or polarized plugs (one prong wider than the other).
• Extension cords may only be used on temporary equipment (or equipment which must be moved frequently) and must be rated so as to be adequate for the equipment they serve.
• Permanent equipment (to be in place or has been in place more than 6 months) must have permanent wiring- not extension cords. Extension cords may not be ganged together.
• Power strips with surge protectors are allowed but may not be ganged together.
• All labs should have instructions on where circuit breakers are located to de-energize circuits in the event of emergencies.
• Minimize the use of electrical equipment in cold rooms or other areas where condensation is likely. If equipment must be used in such areas, mount the equipment on a wall or vertical panel.
• Do not place power strips in front of fume hoods or any other location where liquids re routinely handled.
• Electrical outlets may not be located within 24 inches of the center of an emergency shower spray area.
• Electrical outlets located between 24 and 72 inches of the center of an emergency shower spray area must be GFCI equipped.

Electrical equipment located between 24 and 72 inches of the center of an emergency shower spray area must be protected from water spray and powered via a GFCI equipped outlet.