Which method is effective for extinguishing a Class A fire?

Using foam or multipurpose dry chemical extinguishers is effective for extinguishing a Class A fire, which typically involves ordinary combustible materials such as wood, paper, cloth, and some plastics. These extinguishers work by cooling the burning material and creating a barrier between the fuel and the oxygen in the air, thereby interrupting the fire triangle necessary for combustion.

Foam extinguishers are particularly well-suited for Class A fires, as they can spread over the surface of the burning material and smother the flames, while multipurpose dry chemical extinguishers contain agents that can suppress the fire by interrupting the chemical reactions occurring in the flames. This method is preferred not only for its effectiveness in extinguishing Class A fires but also for the versatility of multipurpose extinguishers, which can be useful against a variety of fire classes.

Other options may not effectively target Class A fires. For example, carbon dioxide is better suited for Class B (flammable liquids) and Class C (electrical) fires, as it displaces oxygen and does not cool the material down effectively. A fire blanket is primarily for smothering smaller fires or those on a person but may not be practical or effective for larger materials. Sand can be used as a