Which extinguisher class would be used for a fire involving electrical equipment?

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

Answer: (D)

When a fire involves electrical equipment, the priority is to control the flame without creating a path for electricity to travel through you. Water and other conductive agents can carry current, posing a serious shock risk and potentially making the fire worse. Extinguishers designed for electrical fires use non-conductive agents that can interrupt the flame while minimizing the chance of electrical contact. Common choices are dry chemical powders and carbon dioxide, which are effective on energized electrical equipment and safe for the operator when used properly. Because the power should be turned off if possible, the situation can then be reassessed for the fuel involved and treated accordingly. Fire extinguishers intended for ordinary combustibles, flammable liquids, or metal fires aren’t appropriate for live electrical fires because they don’t address the electrical risk and can introduce new hazards.