ABC fire extinguishers are often the ideal choice because they can put out many different types of fires. They use a dry chemical known as monoammonium phosphate that can quickly put out the fire. It is a pale-yellow powder that is used to extinguish three classes of fire. ABC fire extinguishers are considered “tri-class” or “multi-purpose” extinguishers which can be used on Class A, B, or C fires.
Every fire extinguisher has an alphabet rating that tells you what types of fires it can extinguish. The letters stand for the class of fire the extinguisher can be used against:
Class A – extinguish fires involving paper, wood, textiles, cloth, rubber, trash, and plastics.
Class B – extinguish fires involving flammable liquids, solvents, oil, gasoline, paints, lacquers, and other oil-based products.
Class C – extinguish fires involving energized electrical equipment such as wiring, controls, motors, machinery, and appliances.
How does an ABC fire extinguisher work?
Dry chemical extinguishers contain foam or dry powder with compressed nitrogen as the propellant. They work by smothering the fire: when you put a layer of powder or foam on the fire, you cut the fuel off from the oxygen around it, and the fire goes out.
It is important to know how to use a fire extinguisher correctly. Remember the word PASS:
- Pull the pin.
- Aim the nozzle at the base of the fire. Hitting the tops of the flame with the extinguisher will not put the fire out effectively.
- Squeeze the trigger slowly and evenly to release the agent.
- Sweep the nozzle from side to side until the fire is put out.
An extinguisher with an ABC rating is suitable for use with fires involving ordinary combustibles, flammable liquids, and energized electrical equipment. An extinguisher that is rated for use with multiple hazards should include a symbol for each hazard type. If you have any questions about fire extinguishers or need training in the correct way to use one, call Fire Control Systems today.