The ABCDs of Portable Fire Extinguishers

A fire extinguisher's label tells the kind of fire on which it is to be used: wood or cloth, flammable liquids, electrical, or metal. Extinguishers are labeled A, B, C or D. Using the improper type of extinguishing agent can make fighting the fire harder.

Extinguishers labeled A are for ordinary combustibles. They use a water-base type agent or multipurpose dry chemical. They are used on fires in paper, cloth or wood. Extinguishers should be identified by a triangle containing the letter A, colored green.

Extinguishers labeled B use agents such as Halons, carbon dioxide, aqueous film-forming foam (AFFF) or dry chemicals. They are used on fires in flammable liquids, oils, gasoline, some paints, lacquers, grease in a frying pan or in the oven, solvents, and other flammable type liquids. Extinguishers suitable for Class B fires should be identified by a square containing the letter " B" colored red.

Extinguishers labeled C are for electrical equipment and fires in wiring, fuse boxes, energized electrical equipment and other electrical sources. Extinguishing agents for C extinguishers are the same as for A and B extinguishers providing the agent is electrically non-conductive (not water base). Extinguishers suitable for Class "C" fires should be identified by a circle containing the letter "C" colored blue.

Extinguishers labeled D are for fires in combustible metals such as magnesium and sodium. Extinguishers labeled D are not equally effective on all combustible metal fires. The manufacturer should be consulted for the specific combustible metal involved. Extinguishers suitable for fire involving metals should identified by a five-pointed star containing the letter " D " colored yellow.

If you plan to buy one extinguisher for your home, a multipurpose dry chemical extinguisher labeled ABC puts out most types of fires: wood, paper and cloth, flammable liquid, or electrical fires.

If you buy more than one, you might want to get a BC for the kitchen, an A for the living room, and an ABC for the basement and garage.

Recently, pictogram labels have appeared on fire extinguishers. These picture in blue the types of fire on which an extinguisher is to be used. They also show in black with a red slash pictures of fires on which the extinguishers are not to be used.

Whether the fire extinguisher in your work space or home has A, B, C or D labeling, or both the pictograms and the A, B, C or D labels, be sure to familiarize yourself with the extinguisher and the type of fire on which it can be used.

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