Which statement about Carbon Dioxide extinguishers is true?

Which statement about Carbon Dioxide extinguishers is true?

• A. Most effective on Class B and Class C fires
• B. Most effective on Class A fires
• C. Not suitable for any commercial use
• D. Safer for electrical equipment enclosure than water

Answer: (A)

Carbon dioxide extinguishers smother flames by displacing the air, rather than cooling the fuel. This makes them a good fit for fires where cooling isn’t required and where placing a blanket of gas can interrupt the flame, especially in enclosed spaces with electrical equipment or liquid fuels. Because of this behavior, they’re most effective on Class B (flammable liquids) and Class C (electrical) fires — the situations where smothering and lack of residue are advantageous. They aren’t suitable for ordinary combustibles like wood or paper, which need cooling to prevent reignition. The safety note about using CO2 in electrical enclosures is context-dependent and not the primary point about effectiveness, whereas the main takeaway is CO2’s effectiveness for B and C fires.

Carbon dioxide extinguishers smother flames by displacing the air, rather than cooling the fuel. This makes them a good fit for fires where cooling isn’t required and where placing a blanket of gas can interrupt the flame, especially in enclosed spaces with electrical equipment or liquid fuels. Because of this behavior, they’re most effective on Class B (flammable liquids) and Class C (electrical) fires — the situations where smothering and lack of residue are advantageous. They aren’t suitable for ordinary combustibles like wood or paper, which need cooling to prevent reignition. The safety note about using CO2 in electrical enclosures is context-dependent and not the primary point about effectiveness, whereas the main takeaway is CO2’s effectiveness for B and C fires.