What classification of fire extinguisher is used for ordinary combustibles?

The classification of fire extinguishers is based on the type of materials that contribute to the fire. For ordinary combustibles, which include materials such as wood, paper, cloth, trash, and some plastics, a Class A fire extinguisher is specifically designed to address these types of fires. The extinguishing agent used in Class A extinguishers, typically water or foam, effectively cools the burning material and removes heat from the fire triangle, thereby extinguishing the flames.

Class B extinguishers are suited for flammable liquids and gases, such as gasoline, oil, and grease, while Class C extinguishers are meant for electrical fires that involve energized electrical equipment. Class D extinguishers are used for fires involving combustible metals, which are not relevant when dealing with ordinary combustibles.

Therefore, because ordinary combustibles fall under the Class A category, this classification is fundamental in understanding which fire extinguisher to utilize in these situations.