Which statement about Class D extinguishing agents is true?

Which statement about Class D extinguishing agents is true?

• A. They are universal for all metals
• B. They must be stored under water
• C. The specific agent must be matched to the specific fuel
• D. They do not require training

Answer: (C)

Class D fires involve combustible metals, which burn and react in ways that ordinary extinguishing methods can’t safely handle. The essential principle here is that the extinguishing agent must be chosen to match the specific metal fuel. Dry powder extinguishers designed for metal fires create a protective crust or barrier on the metal surface and help absorb heat, stopping the chemical reactions at the fuel surface. Because different metals have different burning behaviors and can react with certain powders, using the right agent for the metal is crucial to shut down the fire safely and effectively. If the wrong powder is used, it may be ineffective or even worsen the situation by triggering a violent reaction or spreading the burning metal.

Notes on the other statements: there isn’t a universal extinguisher for all metals, water should not be used on metal fires due to dangerous reactions, and training is required to correctly identify the metal and apply the correct agent and technique.