Water-based extinguishers are used to put out which class of fires?

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

Answer: (A)

Water-based extinguishers remove heat from the fire by cooling the fuel, which is most effective on ordinary combustibles like wood, paper, and fabrics. This cooling action lowers the temperature of the fuel below its ignition point, stopping the combustion process and preventing reignition. Because of this, water-based extinguishers are best suited for fires involving solid, everyday materials.

They aren’t appropriate for flammable liquids, electrical equipment, or reactive metals. Water can spread flammable liquids, making the fire worse, and it conducts electricity, posing a shock hazard on electrical equipment. For reactive metals, water can trigger dangerous reactions. So, while water-based extinguishers excel on common solid fuels, other extinguishing methods are used for the other fire types.