A fire involving energized electrical equipment is best fought with which class extinguisher?

A fire involving energized electrical equipment is best fought with which class extinguisher?

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

Answer: (D)

Fires involving energized electrical equipment require methods that won’t conduct electricity and won’t create a shock hazard. The best choice is an extinguisher intended for electrical fires, using a non-conductive agent such as carbon dioxide or dry chemical to suppress the flame without passing electricity through you. This is safer and more effective for electrical fires than extinguishers designed for ordinary combustibles, liquids, or metals. Water-based extinguishers must be avoided on energized electrical fires because water conducts electricity and can create a dangerous shock path. If it’s safe to do so, shut the power off before fighting the fire; if not, rely on the non-conductive extinguishing agent and call for help. The other extinguisher types do not address the electrical hazard and are not appropriate for fires involving energized equipment.