We're sorry, but OSHAcademy doesn't work properly without JavaScript enabled. Please turn on JavaScript or install a browser that supports Javascript.

615 Electrical Safety - Hazards and Controls
Skip to main content

Defective Insulation Hazards

Insulation that is defective or inadequate is an electrical hazard. Usually, a plastic or rubber covering insulates wires. Insulation prevents conductors from coming in contact with each other and with people.

Inadequate insulation cause this electrical short and fire
Inadequate insulation caused a short and fire.

Extension cords: Extension cords may have damaged insulation. Sometimes the insulation inside an electrical tool or appliance is damaged. When insulation is damaged, exposed metal parts may become energized if a live wire inside touches them.

Tools: Electric hand tools that are old, damaged, or misused may have damaged insulation inside. If you touch damaged power tools or other equipment, you may receive a shock. You are more likely to receive a shock if the tool is not grounded or double-insulated. Double-insulated tools have two insulation barriers and no exposed metal parts.

You must recognize that defective insulation is a hazard.

Knowledge Check Choose the best answer for the question.

2-5. While working with electric hand tools, when are you more likely to receive a shock?