Extension Cord Safety

Nothing about an extension cord suggests danger – there are no moving parts, no flames, no noise. It is harmless looking, yet it can be extremely dangerous if misused. High quality extension cords should be used all the time – cords that are rated “heavy duty” and approved and tested by Underwriter’s Laboratories. Cords that show wear should be repaired or thrown out.


The U.S. Consumer Product Safety Commission (CPSC) estimates that each year, about 4,000 injuries associated with electric extension cords are treated in hospital emergency rooms. About half of the injuries involve fractures, lacerations, contusions or sprains from people tripping over extension cords.

Misuse of extension cords can cause short circuits, overloading, sometimes resulting in fires.


There are some hazards in using extension cords that you can control.

No extension cord can stand rough usage.
If you kink it, knot it, or crush it and even bend it, you can break the insulation, which may cause a short circuit and a fire or even an electric shock.

Most cords used carry regular 110-volt electricity.
No doubt at some time you have received a shock from a 110-volt line without serious harm – just a great tingling sensation. But even a 10-volt current can kill. It is not harmless.

The conditions, however, must be right.
The right conditions may consist of making a good connection with a live wire carrying a 110 voltage with wet or sweaty hands, standing or lying on the ground, a wet floor, a water pipe or another electrical connection.


Protect the extension cords you use.

  1. Coil them in large loops, not in close kinked coils.
  2. Don’t bend them unnecessarily.
  3. Don’t repair them yourself.

In special situations, special types of cords are needed. Some cords are water-resistant, others are not. Some are insulated for heat resistance; others are designed to stand the action of solvents and other chemicals that may be present.


For the safe use of extension cords:

  • Inspect all extension cords at the beginning of each workday for any signs of wear or damage. Remove any worn, severely discolored or damaged cords from service immediately.
  • Handle the cord gently, avoiding strain, kinking, crushing or cutting.
  • String it where it will not be hit or tramped on.
  • If moisture, heat or chemicals are present, be sure your cord is the proper type to resist the conditions that are present.
  • Extension cords should not be used as ropes to raise and lower tools and materials.
  • If a cord is unusable but repairable, tag it out until it is fixed.
  • Use extension cords only when necessary and only on a temporary basis. Do not use extension cords in place of permanent wiring.
  • Do not remove the prongs of an electrical plug. If plug prongs are missing, loose, or bent, replace the entire plug.
    • Before each use, check the cord for the presence of a ground blade on the male end of the cord.
  • Only use cords rated for outdoor use when using a cord outside.
  • Do not run cords above ceiling tiles or through doors or walls.
  • Never unplug an extension cord by pulling on the cord; pull on the plug.


Download a PDF of this Toolbox Talks