Class A fires involve which materials?

• A. Flammable Gases
• B. Solid Materials
• C. Combustible Metals
• D. Flammable Liquids

Answer: (B)

Fires in this category involve ordinary combustibles—solids that burn and often leave ash behind. This includes solid materials like wood, paper, cloth, and many plastics. Because the fuel is a solid, the heat has to be cooled below the material’s ignition temperature to stop the burn, which is why cooling with water is effective for these fires.

Gases and liquids burn as vapors or liquids, respectively, and metals burn in their own metal-specific class, so they don’t fit the solid-fuel description. That’s why the solid materials option best matches Class A fires: it specifically refers to solids that burn and form ash, unlike the other material states or metal categories.