Which statement describes a benefit of using CO2 extinguishers on electrical fires?

• A. They displace oxygen and leave minimal residue.
• B. They leave a lot of residue on electrical equipment.
• C. They are not effective on electrical fires.
• D. They require contact to burn longer.

Answer: (A)

Electrical fires require an extinguishing agent that won’t conduct electricity and won’t leave conductive residue on energized equipment. Carbon dioxide fits this need: it is a clean, non-conductive gas that blankets the flame and displaces the surrounding oxygen. By starving the fire of oxygen, it suffocates the flame, and because it leaves minimal residue, there’s less risk of creating conductive paths or requiring extensive cleanup on electrical gear. This combination—displacing oxygen to smother the fire and leaving little to no residue—explains why CO2 extinguishers are beneficial for electrical fires. The other statements either overstate residue, claim ineffectiveness, or imply a requirement for longer burn time, which aren’t accurate for how CO2 behaves in this context.