If you work in an environment where an accidental fire is a possibility, it is important to familiarize yourself and understand the different types of fire extinguishers. Using the wrong type of fire extinguisher can be dangerous and ultimately cost you your life or someone else’s. There are several different types of fire extinguishers that are commonly used in the workplace and in private home applications. These include:
- Class A – used for combustible materials including wood, plastic, cardboard, and paper. The symbol on the label contains a green triangle.
- Class B – used for flammable and combustible liquids including grease, kerosene, gasoline, and oil. The symbol on the label contains a red square.
- Class C – used for electrical materials including outlets, circuit breakers, appliances and wiring. The agent contained in the extinguisher for a Class C fire is generally non-conductive. The symbol on the label contains a blue circle.
- Class D – used for chemical fires from combustible materials such as titanium, sodium, potassium and magnesium. The symbol on the label contains a yellow decagon.
- Class K – used for fires from fats, cooking oils and trans fats from fires in commercial kitchens. The symbol on the label contains a black hexagon.
Types of Fire Extinguishers
Water extinguishers are to be used for Class A fires only. Some people try to extinguish grease or electrical fires with water and find that the flames spread, making the fire larger. A water extinguisher should only be used on fires that involve combustible materials.
Chemical extinguishers can contain several types of chemical, usually foam or a powder that is pressurized with nitrogen. A regular dry chemical extinguisher is filled with sodium or potassium bicarbonate. A BC extinguisher can leave a corrosive residue behind, which should be cleaned as quickly as possible to minimize damage to surfaces.
The ABC extinguisher contains monoammonium phosphate. This is a yellow powder that can leave a sticky residue behind. The residue can cause damage to electrical appliances. Dry chemical extinguishers are the most commonly used extinguishers, and leave behind a substance that is non-flammable to prevent the fire from re-igniting.
It is important to ensure that you have the correct type of fire extinguisher located near the materials that need to be extinguished. For example, it you have a fire extinguisher in your kitchen, it should be a Class B or a Class K fire extinguisher as opposed to a Class A extinguisher. Trying to use the wrong type of extinguisher on a fire can cause a fire to spread and burn out of control.
Fire extinguishers are meant to contain a fire to allow people to get out of a home or for workplace safely. The fire department should always be contacted to follow up on the fire, even if you believe it has been completely extinguished.
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