Types of Fire Extinguishers
To understand the types of fire extinguishers, you need to first understand the common types of fires. Household fires fall under three classifications, depending on the type of fuel burning. The most common fire extinguisher classifications are A, B, C, and K.
- Class A: Solid combustibles that are not metals, like wood, paper, cloth, plastics, and rubber.
- Class B: Flammable liquids, like gasoline, oil, grease, and paints.
- Class C: Electrical equipment, like appliances and outlets.
- Class K: Cooking oils and greases, animal fats, and vegetable fats.
Household extinguishers fight specific types of fires. It’s important to know the type of fire that has started before you use a fire extinguisher on it; different extinguishers use different chemical fueling agents to fight fires and are effective only on specific types of fuel. If you use the wrong type of extinguisher, you can make a fire worse. Always check fire extinguisher labels before use, and familiarize yourself with which type of extinguisher is best for each type of fire.
Air-Pressurized Water (APW) Extinguishers
Air-pressurized water extinguishers use pressurized water to fight Class A fires only. These extinguishers are generally about two feet tall and twenty-five pounds when full and have a pressure gauge. Do not use water on Class B or C fires, as it may cause the fire to spread or increase the possibility of electrical shock.
Foam extinguishers are effective against Class A and B fires. They are not recommended for Class C fires, but are safer than APW extinguishers if accidentally used on a live electrical device. Foam fire extinguishers are generally marked with a blue band and can vary widely in size.
Carbon Dioxide (CO2) Extinguishers
Carbon dioxide extinguishers use non-flammable CO2 gas to fight Class B and C fires. They are not generally effective against Class A fires. These extinguishers do not a have a pressure gauge and can range from 5 to 100 pounds.
Dry Chemical (DC) Extinguishers
Dry chemical extinguishers may be labeled ABC or BC to indicate which types of fires they can be used on. They are generally filled with mono-ammonium phosphate and are pressurized using nitrogen. They range from five to twenty pounds and have a pressure gauge.
Most residential fire extinguishers use dry chemicals and are classified ABC to effectively combat all three common household fire types. Rechargeable extinguishers are heavier, but they are sturdier and can be refilled and reused. Disposable extinguishers with plastic valves are lighter and cheaper than rechargeable extinguishers, but they have a shorter shelf life and can be used only once. Cover all your bases and get an ABC fire extinguisher so you’ll be prepared for anything.
Where will you use the fire extinguisher?
Because fire hazards can vary from room to room, it’s smart to select an extinguisher that can combat the type of fire most likely to occur. If you’re looking for a kitchen fire extinguisher, you want to make sure you select one that is rated for Class K fires. However, if you want to protect your wooden shed, a Class A extinguisher that can battle wood fires is the right choice. In addition, there are portable extinguishers for use in cars, on boats, and other remote locations where you may need a fire extinguisher on the go.
Who will use the fire extinguisher?
Another thing to consider is who will need to use the fire extinguisher in the event of an emergency. Some extinguishers are large and heavy, which makes them difficult for smaller family members to properly discharge. If you’re placing a fire extinguisher in an area where younger or older family members may need to use them, consider the weight those family members can reasonably manage. Children should not discharge fire extinguishers, but older teens may be trained to handle them.
How will you store your fire extinguisher?
There are different ways to store a fire extinguisher, but it’s important to make them easy to access in the event of a fire. Many extinguishers come with wall mounting brackets that make it easy to store the extinguisher just about anywhere. If you choose to mount your fire extinguisher, place it approximately four to five feet above the floor, where it can’t be tampered with by little ones or pets.
Another option is to store the fire extinguisher in a cupboard or other safe place, preferably near an exit and far from the oven or fireplace. Because fire extinguishers typically withstand temperatures up to only 120°F, you don’t want them too near appliances or other heat-producing elements. Before you purchase a new fire extinguisher, scope out where you want to store it and pick one that will securely fit in your chosen spot.
What do fire extinguisher ratings mean?
Fire extinguisher labels include symbols to indicate which types of fires the extinguisher is designed to fight. If there is a circle and a red slash through any of the symbols, that indicates that the extinguisher cannot be used to fight that type of fire.
Household fire extinguishers are also rated for the size of fire they can safely handle. The higher the rating, the larger the fire the extinguisher can put out. Class A fire extinguishers are rated 1 to 40, which indicates the equivalency to gallons of water. An extinguisher with a 1A rating has the firefighting power of 1.25 gallons of water, a 2A rating indicates 2.5 gallons, and so on. Class B fires are rated from 1 to 640, to indicate the square footage the extinguisher can handle. For example, an extinguisher with a 20B rating could cover up to twenty square feet. There is no size rating for Class C fires. Note that higher-rated extinguishers are often heavier, so be sure that you (and any other adult household members) can comfortably handle the size of the fire extinguisher you keep at home.