The Right Fire Extinguisher for the Right Fire
Fire extinguishers come in a wide variety of types — each one designed to put out a different kind of fire. Classification systems have been developed to help users know what sort of extinguisher they’re working with. Because the majority of our readers are based stateside, I’ll be focusing on the system used to classify extinguishers in the US.
- Class A – Ordinary solid combustibles like wood, cloth, and paper products.
- Class B – Flammable liquids and gases.
- Class C – Electrical fires. (Do not use water to put out this kind of fire – you could get electrocuted!)
- Class D – Flammable metals.
- Class K – Oils and grease fires. (Never use water on a grease fire – it will cause the flames to explode and spread.)
Most fire extinguishers for homes and public spaces are classified as Class ABC extinguishers, meaning they’re suitable for putting out wood and paper fires, flammable liquid fires, and electrical fires. ABC extinguishers use the dry chemical monoammonium phosphate as the extinguishing agent.
If you’ve worked in a commercial kitchen, you’ve probably seen Class K extinguishers. The extinguishing agent in the Class K variety is a wet potassium acetate. (Interesting fact: Before the introduction of potassium acetate, sodium bicarbonate powder was the extinguishing agent of choice for grease and oil fires – that’s why baking soda can work in a pinch).
How To Use Fire Extinguisher - PASS
To employ the extinguisher with proper technique, just remember the acronym “PASS.”
- Pull the pin.
- Aim the nozzle at the base of the fire. Hitting the tops of the flame with the extinguisher won’t be effective. You got to smother the sucker at its base.
- Squeeze the trigger. In a controlled manner, squeeze the trigger to release the agent.
- Sweep from side to side. Sweep the nozzle from side to side until the fire is put out. Keep aiming at the base while you do so. Most extinguishers will give you about 10-20 seconds of discharge time.