What type of fire is Class A?

• A. Fires that involve organic materials that leave ash
• B. Fires burning liquids like fuel and oil
• C. Electrical fires in wiring
• D. Fires involving metals

Answer: (A)

Fires involving ordinary combustibles that leave ash are Class A. This includes materials like wood, paper, and cloth, which leave behind ash as they burn. The key idea is that these fuels form solid residues and are best extinguished by cooling with water or water-based agents, which stops the burning process by lowering the material’s temperature. The other categories describe different kinds of fires: burning liquids such as fuel or oil are Class B; electrical fires in wiring are Class C; and fires involving metals are Class D. So the description of organic materials that leave ash matches Class A.