Fact Sheet

Office Electrical Safety

Electrical equipment used in an office is potentially hazardous and can cause serious shock and burn injuries if improperly used or maintained.

Electricity travels through electrical conductors which may be in the form of wires or parts of the human body.

Most metals and moist skin offer very little resistance to the flow of electrical current and can easily conduct electricity. Other substances such as dry wood, porcelain, or pottery offer a high resistance and can be used to prevent the flow of electrical current.

If a part of the body comes in contact with the electrical circuit, a shock will occur. The electrical current will enter the body at one point and leave at another.

The passage of electricity through the body can cause great pain, burns, destruction of tissue, nerves, and muscles and even death.

Factors influencing the effects of electrical shock include the:

The longer the current flows through the body, the more serious the injury. Injuries are less severe when the current does not pass through or near nerve centers and vital organs.

Electrical accidents usually occur as a result of faulty or defective equipment, unsafe installation, or misuse of equipment on the part of office workers.

Types of electrical hazards found in an office environment

Ungrounded Equipment

Grounding is a method of protecting users of electrical equipment from electric shock. Grounding an electrical system intentionally creates a low-resistance path to earth through a ground connection. When properly created, this path offers sufficient low resistance and has sufficient current-carrying capacity to prevent the build-up of hazardous voltages.

Most fixed equipment, such as large, stationary machines, must be grounded. Equipment connected to electricity by cord and plug must be grounded if located in hazardous or wet locations, if operated at more than 150 volts to ground, or if a certain type of equipment (such as refrigerators and air conditioners). Smaller office equipment, such as typewriters and coffee makers, would generally not fall into these categories and therefore would not have to be grounded. However much of the newer office equipment is manufactured with grounded three-prong plugs as a precaution. In such cases, the equipment should be used in accordance with the manufacturer’s instructions. In any case, never remove the third (grounding) prong from any three-prong piece of equipment.

Overloaded Outlets

Avoid not having enough outlets or overloading the electrical outlets available. A sufficient number of outlets will eliminate the need for extension cords. Overloading electrical circuits and extension cords can result in a fire. Floor-mounted outlets should be carefully placed to prevent tripping hazards.

Unsafe/Non-Approved Equipment
The use of poorly maintained or unsafe, poor-quality, non-approved (by national testing laboratory) coffee makers, radios, lamps, space heaters, etc. (often provided by or used by employees) should be discarded. Such appliances can develop electrical shorts creating fire and/or shock hazards. Equipment and cords should be inspected regularly, and a qualified individual should make repairs.

Defective, frayed or improperly installed cords for electrically-operated office equipment

When the outer jacket of a cord is damaged, the cord may no longer be water-resistant and the insulation can absorb moisture, which may then result in a short circuit or excessive current leakage to ground. If wires are exposed, they may cause a shock to a worker who contacts them. These cords should be replaced. Electric cords should be examined on a routine basis for fraying and exposed wiring.

Improper Placement of Cords

A cord should not be pulled or dragged over nails, hooks, or other sharp objects that may cause cuts in the insulation. In addition, cords should never be placed on radiators, steam pipes, walls, or windows, or under carpets, rugs or furniture. Particular attention should be placed on connections behind furniture, since files and bookcases may be pushed tightly against electric outlets and severely bend the cord at the plug.

Electrical Cords Across Walkways and Work Areas

An adequate number of electrical outlets should be provided. Extension cords should only be used in situations where fixed wiring is not feasible. However, if it is necessary to use an extension cord, avoid running it across walkways where it poses a potential tripping hazard. If it is unavoidable to run a cord across a walkway, either tape it down with duct or other industrial tape made for the purpose, or purchase a cord runner.

Live Parts Unguarded

Wall receptacles should be designed and installed so that no current-carrying parts will be exposed, and outlet plates should be kept tight to eliminate the possibility of shock.

Pulling of Plugs to Shut Off Power

On/off switches should be provided either on the equipment or on the cords o avoid having to pull the plug to shut off the power. Never pull a plug out by the cord. To remove a plug from an outlet, take a firm grip on and pull the plug itself.

Working on “Live Equipment”

Disconnect electrical machines before cleaning, adjusting, or applying flammable solutions. If a guard is removed to clean or repair parts, replace it before testing the equipment and returning the machine to service.

Blocking Electrical Panel Doors

If an electrical malfunction should occur, the panel door, and anything else in front of the door will become very hot. Electrical panel doors should always be kept closed, to prevent “electrical flashover” in the event of an electrical malfunction.

Recommendations

Electrical appliances can be fire hazards. Be sure to turn off all appliances at the end of the day. Use only grounded appliances plugged into grounded (three prong plugs) outlets.

If electrical equipment malfunctions or gives off a strange odor, disconnect it and call the appropriate maintenance personnel. Promptly disconnect and replace cracked, frayed, or broken electrical cords.

Keep extension cords clear of doorways and other areas where they can be stepped on or chafed and never plug one extension cord into another.

Don’t fasten extension cords with staples, hang from nails, or suspend by wire.

Use special insulated tools when working on fuses with energized terminals.

Don’t use equipment with worn or frayed cords and cables.

Plugs should fit securely into outlets, but never force a plug into an outlet if it doesn’t fit.

Check for outlets that have loose-fitting plugs, which can overheat and lead to fire.

Ensure extension cords and electrical products are listed by an independent testing facility such as Underwriters Laboratories Inc. (UL), CSA, ETL or MET labs, and are properly rated for their intended use, indoor or outdoor, and meet or exceed the power needs of the appliance or tool being plugged into it.

Ensure all appliances are all certified by an independent testing laboratory such as UL, CSA, ETL or MET Labs, and read and follow the manufacturer’s instructions carefully.

Resources

NIOSH Electrical Safety

OSH Answers: Electrical Safety-Basic Information, Canadian Centre for Occupational Safety and Health

OSHA Safety & Health Topics: Electrical

Safety and Electricity Checklist