Which extinguisher class is used for ordinary combustibles?

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

Answer: (A)

Fires involving ordinary combustibles like wood, paper, and cloth are addressed by Class A extinguishers. They work by cooling the fuel below its ignition temperature, usually using water or a water-based agent. This cooling action slows the flame and prevents re-ignition, making Class A the best fit for those kinds of fires. Other fuel types require different classes—flammable liquids fall under Class B, energized electrical equipment under Class C, and cooking oils under Class K—so matching the extinguisher to the fuel is key for effective control.