Combustible metals correspond to which class?

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

Answer: (A)

Fire classifications separate combustible metals because their fires act differently from other fuels and need special extinguishing methods. Metals such as magnesium, titanium, or sodium burn at very high temperatures and can react violently with water, sometimes producing hydrogen gas that can ignite. Because of these properties, metal fires are designated Class D, indicating that a dry powder extinguisher or another metal-specific agent is needed to smother the fire and separate the metal from the oxygen. Using water, foam, or standard CO2 extinguishers can be ineffective or dangerous for metal fires.

Other classes cover different fuels: Class A is ordinary combustibles like wood and paper, Class B is flammable liquids, and Class F covers cooking fats and oils. These classifications do not apply to metal fires, which is why the correct designation is Class D.