Class A fire extinguishers are used for ordinary combustibles, such as paper, wood, cloth, and some types of plastic. These extinguishers typically use water or certain types of dry chemicals to either absorb heat or coat the fire.
Fires that originate from flammable liquids and gas can be extinguished by a class B fire extinguisher. This is the type of extinguisher you’ll want to use on a fire caused by oil or fuel.
Class C fire extinguishers are effective against electrical fires, generally from live wires, panels, and circuit breakers. The extinguisher works by releasing materials that stop the conduction of electricity.
Class D fire extinguishers are used on combustible metals. These include magnesium, sodium, aluminum, and titanium.
Commonly used in restaurant kitchens, class K fire extinguishers can effectively put out fires caused by cooking fats, greases, and oils. They release an alkaline agent to create a foam that traps vapors and puts the fire out.