A single fire extinguisher isn’t enough to battle every kind of fire, which is why fire extinguishers have been divided into different classes depending on their source. In fact, every class of fire has its own fire extinguishers. There are also multipurpose fire extinguishers that put out different kinds of fire in one go. ABC fire extinguishers are one of them.
In this article, we go over everything you need to know about ABC fire extinguishers: what chemicals they use, what are the different sizes, and what kinds of fire they can put out.
What Chemicals Are In an ABC Fire Extinguisher?
ABC fire extinguishers use a dry chemical powder called monoammonium phosphate to put out the ABC classes of fire.
This dry chemical puts out the fire by coating the flames with a thin layer of dust and blocking the flammable oxygen supply to the source.
ABC Fire Extinguisher Sizes
ABC fire extinguisher sizes range from 2 to 10 pounds. They come in different designs that can be mounted in various locations, including above stoves.
DIfferent size options have their own pros and cons, including:
|Size of the Fire Extinguisher||Great For||Keep in Mind!|
|10 pound||A 10-pound fire extinguisher is perfect for home, garage, or workshops where the fire spreads without being noticed.||You should look for a rechargeable model that comes with a hose.|
|5 pound||Easy to grab for usage in the kitchen or laundry.||You should look for a rechargeable model that comes with a hose.|
|2 pound||Perfect for keeping in the car.||It might come with a mounting hardware.|
|Stove-top||Stove-top fire extinguishers are great for mounting on a range hood over a stove.||These come with pressurized magnetic cans designed to pop automatically from the heat of flames and release baking soda to put them out.|
How Is an ABC Fire Extinguisher Designed?
The ABC fire extinguishers are multipurpose and use a dry chemical called monoammonium phosphate to put out A, B, and C fires which are described as follows:
- Class A flames are caused by wood, cloth, or paper.
- Class B flames are caused by liquids and gases.
- Class C flames are caused by energized electrical sources.
ABC Fire Extinguisher Labeling
The ABC fire extinguisher is labeled ‘powder’ in white text over a blue rectangle on the container. The words ‘ABC powder’ are written under the blue rectangle.
This powder is non-conductive, which makes it suitable for electrical or Type C fires as well. However, the powder leaves behind a residue that’s difficult to clean up and might cause damage to carpets, furniture, and electrical equipment.
Do ABC Fire Extinguishers Work On Grease Fires?
Yes. ABC fire extinguishers work on grease, oil and kitchen fires.
A grease fire happens when the cooking oil becomes too hot, resulting in heavy smoke and eventually a fire. This fire may spread to other kitchen items, including paper towels, cleaning rags, electric appliances.
Kitchen grease fires require a Class K fire extinguisher to put them out. But these types of specialized fire extinguishers are pricey.
A great alternative is an ABC fire extinguisher. The dry chemical in an ABC fire extinguisher puts out multiple fire sources: grease, oil, wood, clothes, papers, liquids, gases and energized electrical sources.
The only downside is that the ABC extinguisher leaves a heavy residue that gets into the nooks and crannies of the kitchen appliances and is hard to clean up afterward.
When spraying a grease fire in the kitchen, make sure you take these precautions:
- Stand at a safe distance from the fire
- Spray towards the fire instead of directly on it — too much pressure could cause the pan containing the grease to tip over and spread the fire further
Do ABC Fire Extinguishers Work On House Fires?
Yes. ABC fire extinguishers work on house fires, but don’t stand too close to the fire when you’re using it. Make sure you stand back from the flames a bit and let the foam do it’s job.
According to the National Fire Protection Association, a person dies in a house fire every three hours; this makes 3000 annual deaths in the U.S. A home fire extinguisher placed on an easy-to-reach spot in the house can be a life-saver.
A multipurpose ABC fire extinguisher works great for a house where the living room, garage, kitchen, and bedrooms have in them a combination of wood, cloth, paper, liquids, and electrical appliances.
Most house fires are grease fires that start in the kitchen, for which ABC fire extinguishers work very well.
A fire extinguisher kept at home without the check-and-balance of professionals can lose pressure over time. So make sure you are giving the fire extinguisher the maintenance it needs.
Do ABC Fire Extinguishers Work On Car Fires?
Yes. ABC fire extinguishers are well-suited for putting out car fires. They can handle multiple types of combustibles, including electricals, plastics, gasoline and oil.
Car fires start for a variety of electrical and mechanical reasons and can be made worse by:
- Flammable liquids like gasoline and diesel
- Combustible solids like textiles and plastics in the car’s interior
The alternative to the ABC fire extinguisher to put out car fires would be a foam extinguisher, but it’s susceptible to frost, so the ABC fire extinguisher is a better choice.
What Size of the ABC Fire Extinguisher Do You Need for Your Car?
Keeping a 2 to 4 pound fire extinguisher in your car should do the trick; any size smaller than that won’t be effective for a car fire.
The size of your car and the placement of the fire extinguisher also matters; it’s best to keep it under the driver’s seat.
Another thing that counts in picking the right size of the fire extinguisher for your car is the discharge time. 1 kg powder has a discharge time of 6 seconds, whereas 2 kg has a discharge time of 10 seconds.
Caution: If the source of the car fire is the engine, then the ABC dry powder will cause corrosion if left on for too long.
Do ABC Fire Extinguishers Work On Electrical Fires?
While an ABC fire extinguisher may be used for an electric fire, CO2 is the ideal option because they accomplish the same task but don’t leave a residue that can damage electrical devices.
Generally, fire extinguishers with a Class C rating are suitable for ‘live’ electrical equipment. Class C fires involve electronic equipment like servers, motors, transformers, computers, and appliances.
ABC fire extinguishers are not the best for electrical fires, but they can work. They put out the fire, but because they lack cooling properties, the fire may re-ignite.
Caution: When you have a fire with an electric source, avoid water-based fire extinguishers at all costs – the electric-based fire will spread, and you might get electrocuted as well.
Do ABC Fire Extinguishers Work On Wood Fires?
Yes. ABC fire extinguishers put out Class A fires of organic materials like wood, paper, cloth, rubber, and plastics that don’t melt. Because organic matter is everywhere, these kinds of fires spread very fast and require immediate extinguishing.
Any fire extinguisher labeled ‘Class A’ can put out a wood fire, and an ABC fire extinguisher is one of the options. The powder released by an ABC fire extinguisher creates a blanket over the flames that cuts their contact from the oxygen in the air. This prevents it from spreading.
Caution: Unless it’s the only option you have, don’t throw water over an organic fire. Water will instantly make heavy smoke which blacks out the entire space and causes suffocation.
Nick Klamecki is a certified Fire and Workplace Safety expert with 15 years experience in product research and testing. He has a degree in Economics from U.C. Davis, is an active outdoorsman and spent years ensuring the safety of special needs children. Nick researches and tests workplace, industrial and safety products and provides advice on their safe use.