Dry powder extinguishers are rated for which fire class?

• A. Class A
• B. Class B
• C. Class C
• D. Class D

Answer: (D)

Dry powder extinguishers are designed for metal fires. These fires involve combustible metals such as magnesium, titanium, or sodium, which react badly to water and ordinary extinguishing agents. The powder coats the metal surface, creating a barrier between the fuel and the air and helping to cool or interrupt the chemical reaction, effectively smothering the fire. Because of this specialized action, dry powder extinguishers are not used for ordinary combustibles, flammable liquids, or energized electrical fires, which require different extinguishing methods.