Water Fire Extinguisher – Class A is effective because it:

Water Fire Extinguisher – Class A is effective because it:

• A. Smothers by removing air
• B. Controls heat
• C. Reacts chemically to extinguish fire
• D. Dilutes the air by displacement

Answer: (B)

Water extinguishes Class A fires primarily by removing heat. When applied, it absorbs a large amount of heat as it warms and changes to steam, which dramatically lowers the temperature of the burning material and surrounding atmosphere. That cooling keeps the fuel from reaching its ignition temperature and slows or stops the release of flammable vapors, effectively halting the fire. The other ideas describe smothering, a chemical reaction, or displacing air, which aren’t the main ways water works on ordinary combustibles.

Water extinguishes Class A fires primarily by removing heat. When applied, it absorbs a large amount of heat as it warms and changes to steam, which dramatically lowers the temperature of the burning material and surrounding atmosphere. That cooling keeps the fuel from reaching its ignition temperature and slows or stops the release of flammable vapors, effectively halting the fire. The other ideas describe smothering, a chemical reaction, or displacing air, which aren’t the main ways water works on ordinary combustibles.