Which class of fire includes energized electrical equipment?

Which class of fire includes energized electrical equipment?

• A. Class A
• B. Class B
• C. Class C
• D. Class D

Answer: (C)

Fires involving energized electrical equipment are classified as Class C. The presence of electricity means you must use extinguishing methods that won’t conduct electricity or create a shock hazard, so nonconductive agents like carbon dioxide or dry chemical powders are preferred. Water-based extinguishers are avoided on energized electrical fires because water can conduct electricity and is dangerous in this situation. If the power can be shut off and the fire is no longer electrical, the classification may change (to reflect the fuel involved, such as ordinary combustibles or flammable liquids), but while the equipment remains energized, Class C is the correct designation.

Fires involving energized electrical equipment are classified as Class C. The presence of electricity means you must use extinguishing methods that won’t conduct electricity or create a shock hazard, so nonconductive agents like carbon dioxide or dry chemical powders are preferred. Water-based extinguishers are avoided on energized electrical fires because water can conduct electricity and is dangerous in this situation. If the power can be shut off and the fire is no longer electrical, the classification may change (to reflect the fuel involved, such as ordinary combustibles or flammable liquids), but while the equipment remains energized, Class C is the correct designation.