Fire Extinguisher Classes

Class D

Designed for use on flammable metals and are often specific to the metal in question. Class D extinguishers are designed for use on combustible metals, powders, flakes etc. and are often specific to the metal in question. Metals such as magnesium, potassium, titanium, and sodium burn at high temperatures and give off sufficient oxygen to support combustion. These metals react violently with water or other chemicals and must be handled with great care.

Class A

Water-based solution extinguishes burning paper, cloth, and wood trash with a cooling and soaking stream. Class A extinguishers are water-based solutions that are used on paper, cloth, wood, trash, and other common combustible fires. These extinguishers utilize a cooling and soaking stream that is effective on Class A fires.

Class B

Carbon dioxide gas used on fires involving gasoline, paint thinner, hydraulic fluids, and flammable cleaning solvents. Class B extinguishers are pressurized with non-flammable carbon dioxide gas. Class B extinguishers are used on fires involving flammable liquids including grease, gasoline, oil, paint thinner, hydraulic fluids, flammable cleaning solvents, and other hydrocarbon fuels.

Multi-class

Labeled with more than one class, and contains dry chemicals and a non-flammable gas a propellant. Multi-class fire extinguishers are labeled with more than one class designator, such as A-B, B-C, or A-B-C. Multi-class fire extinguishers typically contain dry chemicals and an extinguishing agent that uses a compressed, non-flammable gas as a propellant.

Class C

Non-conductive extinguishing agent used on fires involving energized electrical equipment. Class C fire extinguishers are used on fires involving energized electrical equipment. Such fires must be extinguished using a non-conductive extinguishing agent such as carbon dioxide or a dry chemical.