Which fire class involves energized electrical equipment?

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

Answer: (C)

Fires involving energized electrical equipment are designated as Class C. The presence of live electrical current creates shock hazards and allows electricity to be conducted through many extinguishing agents, so water-based methods are inappropriate for live electrical fires. Nonconductive extinguishing agents are used, and, if possible, the equipment should be de-energized before attacking the fire. Once the electricity is no longer involved, the fire’s classification can shift to reflect the actual fuel, but while the equipment is energized, it falls under Class C. The other classes correspond to different fuel types—ordinary combustibles, flammable liquids, and combustible metals—rather than to electrical hazards.