What type of fires can a water-based fire extinguisher be used for?

A water-based fire extinguisher is effective for extinguishing Class A fires, which involve ordinary combustibles such as wood, paper, cloth, and some plastics. The way a water-based extinguisher works is by cooling the burning material and removing heat from the fire, which is essential in reducing the temperature below the ignition point.

Class A fires are characterized by their fuel sources that absorb water and are extinguished effectively with a stream of water. In contrast, using water on Class B fires (flammable liquids), Class C fires (electrical equipment), and Class D fires (combustible metals) can be dangerous and ineffective. Water can cause flammable liquids to spread, present shock hazards with electrical sources, and may react violently with certain metals. Thus, understanding that water-based extinguishers are specifically suited for Class A fires is crucial for effective fire response training.