All commercially available fire extinguishers will be labeled Class A, B, C, D or K. This indicates the type of fire on which the extinguisher is used.
Class A: Fuel or material consisting of wood, paper, cloth and other combustible solids.
Class B: Fuel consists of flammable liquids such as gasoline, solvents, and so forth.
Class C: An energized electrical wiring or equipment fire. It includes fire in motors, compressors, pumps, electrical tools and switch gears.
Class D: Involves burning combustible metals such as magnesium.
Class K: Involves burning of cooking media such as vegetable or animal oils and fats.