For electrical fires, which class of fire extinguisher is most appropriate?

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

Answer: (B)

The important point is that electrical fires involve energized equipment, so you need an extinguisher that won’t conduct electricity or worsen the hazard. An extinguisher designated for electrical fires uses non-conductive extinguishing agents, allowing you to attack the flame without creating an electrical shock risk. That makes it the best choice for an energized electrical fire.

Extinguishers for ordinary combustibles are meant for materials like wood and paper and don’t address the electrical hazard. Those designed for flammable liquids target liquids and wouldn’t safely or effectively handle an energized electrical source. Metal fires require specialized agents and handling that aren’t appropriate for electrical equipment. So the electrical-fire–rated extinguisher is the one that aligns with the danger and safety considerations of fires involving live electricity.

If it’s safe to do so, you should also try to de-energize the equipment before fighting the fire, and then call for help.