Which materials is the EFRS Dry Powder extinguisher effective on?

• A. Wood, Paper, Cloth
• B. Magnesium, Potassium/Magnesium alloys, Sodium
• C. Plastic, Rubber, Glass
• D. Metal, Ceramic, Glass

Answer: (B)

Metal fires require a different extinguishing approach. Dry powder extinguishers designed for metal fires (Class D) coat the burning metal with powder, creating a barrier between the fuel and air and helping to absorb heat, which slows or stops the reaction. Metals like magnesium, potassium/magnesium alloys, and sodium burn at very high temperatures and can react violently with water or other agents, so a dedicated metal-fire powder is essential. The other materials listed are ordinary combustibles or non-combustibles that are managed by different extinguishing methods, not the metal-specific dry powder. Therefore, the dry powder extinguisher is effective on magnesium, potassium/magnesium alloys, and sodium.