Types of Extinguishers
Fire extinguishers are labeled according to the type of fire on which they may be used. Fires involving wood or cloth, flammable liquids, electrical, or metal sources react differently to extinguishers. Using one type of extinguisher on the wrong type of fire could be dangerous and make matters even worse.
Traditionally, the labels A, B, C or D have been used to indicate the type of fire on which an extinguisher is to be used.
Type A Label
A Type A label is in a triangle on the extinguisher. This extinguisher is used for ordinary combustibles such as cloth, wood, rubber and many plastics. These types of fire usually leave ashes after they burn. Type A extinguishers for Ashes.
Type B Label
A Type B label is in a square on the extinguisher. This extinguisher is used for flammable liquid fires such as oil, gasoline, paints, lacquers, grease, and solvents. These substances often come in barrels. Type B extinguishers for Barrels.
Type C Label
A Type C label is in a circle on the extinguisher. This extinguisher is used for electrical fires such as in wiring, fuse boxes, energized electrical equipment and other electrical sources. Electricity travels in currents. Type C extinguishers for Currents.
Type D Label
A Type D label is in a star on the extinguisher. This extinguisher is used for metal fires such as magnesium, titanium and sodium. These types of fire are very dangerous and seldom handled by the general public. Type D for Don't get involved.
Recently, pictograms have come into use on fire extinguishers. These picture the type of fire on which an extinguisher is to be used. For instance, a Type A extinguisher has a pictogram showing burning wood. A Type C extinguisher has a pictogram showing an electrical cord and outlet. These pictograms are also used to show what not to use. For example, a Type A extinguisher will show a pictogram of an electrical cord and outlet with a big slash through it. In other words, don't use it on an electrical fire.
Fire extinguishers also have a number rating. For Type A fires, a 1 would stand for 1 1/4 gallons of water, a 2 would represent 2 1/2 gallons, 3 would be 3 3/4 gallons of water, etc. For Type B and Type C fire, the number represents square feet. For example, 2 would be two square feet, 5 is five square feet, etc.
Fire extinguishers can also be made to extinguish more than one type of fire. For example, you might have an extinguisher with a label that reads 2A5B. This would mean this extinguisher is good for Type A fires with a 2 1/2 gallon equivalence and it is also good for Type B fires with a 5 square feet equivalency. A good extinguisher to have in each residential kitchen is a 2A10BC fire extinguisher. You might also get a Type A for the living room and bedrooms and an ABC for the basement and garage.