Hazardous Materials are assigned to which class?

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

Answer: (A)

Fires are grouped by what is burning, and Class D is the designation for fires involving combustible metals such as magnesium, titanium, aluminum, sodium, and potassium. These metals burn very hot and can react with water or many common extinguishing agents, so they require special methods—typically specific dry-powder extinguishing agents designed for metal fires.

In the context of hazardous materials, metal-based hazards that can ignite fall under Class D. Other fire classes cover different fuels: ordinary combustibles like wood and paper are Class A, flammable liquids are Class B, and energized electrical equipment is Class C. So for hazardous materials that involve burning metals, Class D is the appropriate classification.