Know your “Types” of Fire Extinguishers

Fire extinguishers are an important tool in preventing a small fire from growing larger. But, they should not be used to combat large or quickly spreading fires. The most important thing to do during a fire situation is to get yourself to safety and call the proper authorities to combat the fire. A building and the property inside are not worth putting yourself or anyone at risk trying to put a fire out with a fire extinguisher. It is important to understand the classes of fires and what fire extinguisher is used for each.

Classes of Fires & what Extinguishers Are Used for Each (source:

Class A: A fire extinguisher labeled with letter “A” is for use on Class A fires. Class A fires are fires that involve ordinary combustible materials such as cloth, wood, paper, rubber, and many plastics.

Class B: A fire extinguisher labeled with letter “B” is for use on Class B fires. Class B fires are fires that involve flammable and combustible liquids such as gasoline, alcohol, diesel oil, oil-based paints, lacquers, etc., and flammable gases.

Class C: A fire extinguisher labeled with letter “C” is for use on Class C fires. Class C fires are fires that involve energized electrical equipment.

Class D: A fire extinguisher labeled with letter “D” is for use on Class D fires. Class D fires are fires that involve combustible metals such as magnesium, titanium, and sodium.

Class K: A fire extinguisher labeled with letter “K” is for use on Class K fires. Class K fires are fires that involve vegetable oils, animal oils, or fats in cooking appliances. This is for commercial kitchens, including those found in restaurants, cafeterias, and caterers.

Common Fire Extinguishers

The most commonly used fire extinguisher is the red ABC extinguisher. This is the multipurpose dry chemical extinguisher. The ABC type is filled with monoammonium phosphate, a yellow powder that leaves a sticky residue that may be damaging to electrical appliances such as a computer. They can be used on A, B, or C type fires.

Another common extinguisher is a silver extinguisher that contains pressurized water. These extinguishers are used for Class A fires only. They should never be used on Class C or Class K fires. Adding water to an electrical or oil fire can cause more damage and injury. Only use water-filled extinguishers for fires that you know are all Class A materials.

Carbon Dioxide (CO2) extinguishers are used for class B and C fires. These extinguishers are usually red too like the ABC extinguishers but have “CO2” clearly marked on them. CO2 extinguishers contain carbon dioxide, a non-flammable gas, and are highly pressurized. They don’t work very well on Class A fires because they may not be able to displace enough oxygen to put the fire out, causing it to re-ignite. These extinguishers do not leave a residue which makes them ideal for electrical fires.

The Final Word

The Final word in dealing with fire extinguishers is PASS – Pull the pin, Aim the nozzle, Squeeze the trigger, Sweep the fire at the base of the flame. 

Stay safe and ensure that you know where the extinguishers are located on your project site and others! 

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