Which agent is used to fight Charlie-class fires?

Which agent is used to fight Charlie-class fires?

• A. Water fog
• B. AFFF
• C. Firemain
• D. CO2

Answer: (D)

Electrical fires involve energized equipment, so the extinguishing agent must be non-conductive and leave no conductive residue. Carbon dioxide fits this need well: it blankets the fire, displaces the oxygen needed to sustain combustion, and won’t create conductive paths or damage sensitive electrical gear. Water-based options like water fog or firemain can energize live components or cause shorts, and AFFF foam, while good for hydrocarbon fires, can spread or contaminate electrical systems. CO2 provides rapid suppression for energized electrical fires with minimal risk to the equipment itself, though it requires proper safety measures for occupants due to asphyxiation hazards.

Electrical fires involve energized equipment, so the extinguishing agent must be non-conductive and leave no conductive residue. Carbon dioxide fits this need well: it blankets the fire, displaces the oxygen needed to sustain combustion, and won’t create conductive paths or damage sensitive electrical gear. Water-based options like water fog or firemain can energize live components or cause shorts, and AFFF foam, while good for hydrocarbon fires, can spread or contaminate electrical systems. CO2 provides rapid suppression for energized electrical fires with minimal risk to the equipment itself, though it requires proper safety measures for occupants due to asphyxiation hazards.