Which extinguisher type is designed for fires involving combustible metals such as magnesium and sodium?

Which extinguisher type is designed for fires involving combustible metals such as magnesium and sodium?

• A. Type A
• B. Type D
• C. Type B
• D. Type C

Answer: (B)

Fires involving combustible metals require a extinguishing agent that won’t react with the metal and can isolate the fuel from the air while cooling the material. Type D extinguishers are designed for this purpose. They use a specialized dry powder that coats the burning metal, smothering the flame and absorbing heat so the metal can’t reignite. Other extinguisher types are tailored to different hazards: ordinary combustibles (wood, paper) with Type A, flammable liquids (gasoline, solvents) with Type B, and electrical fires with Type C. Those options either don’t effectively stop a metal-fire reaction or can be dangerous to use on metal fires (for example, water can react violently with some reactive metals). So for fires involving combustible metals like magnesium and sodium, the extinguisher designed for metal fires—the Type D extinguisher—is the appropriate choice.

Fires involving combustible metals require a extinguishing agent that won’t react with the metal and can isolate the fuel from the air while cooling the material. Type D extinguishers are designed for this purpose. They use a specialized dry powder that coats the burning metal, smothering the flame and absorbing heat so the metal can’t reignite.

Other extinguisher types are tailored to different hazards: ordinary combustibles (wood, paper) with Type A, flammable liquids (gasoline, solvents) with Type B, and electrical fires with Type C. Those options either don’t effectively stop a metal-fire reaction or can be dangerous to use on metal fires (for example, water can react violently with some reactive metals).

So for fires involving combustible metals like magnesium and sodium, the extinguisher designed for metal fires—the Type D extinguisher—is the appropriate choice.