For electrical service fires, which type of extinguisher should be used?

• A. Water
• B. Class C extinguishers
• C. ABC Powder
• D. Foam

Answer: (B)

When fighting an electrical service fire, you must use an extinguisher rated for energized electrical equipment. Water or foam extinguishers are dangerous here because they conduct electricity and can shock you or spread current through energized components. A Class C extinguisher is designed for electrical fires and uses a nonconductive extinguishing media, which helps suppress the fire without energizing the equipment.

ABC powder extinguishers can be used on many fire types and are nonconductive, but the designation that directly indicates suitability for energized electrical fires is Class C. If it’s safe to do so, also shut off the power before fighting the fire, but when dealing with live electrical equipment, the Class C rating is the appropriate choice.