Types of Fire Extinguishers

A fire extinguisher is a handy tool to have around for fighting small or medium-sized fires. They’re useful in homes, offices and public buildings because they can be used to stop the spread of fire and save lives. However, you must use them correctly to ensure they work properly. If you have a fire, the first thing to do is evacuate the area and close any doors. Then call 911. Once the fire department is there, you can try to extinguish the fire with a fire extinguisher. Before you attempt to fight a fire, it’s important to understand how different types of fire extinguishers tackle different types of fires.

Water extinguishers spray a mist of water onto the fire, dousing it in a fine froth that cuts off the oxygen supply and stops it from burning. Water-based extinguishers are usually used for electrical or grease fires. They can also be used to fight class A fires like burning wood, paper or fabric.

Dry chemical extinguishers use powders to smother fires by coating the burning materials. This type of fire extinguisher is rated for use on class A and class B (wood) fires, as well as class C (electrical) fires. Dry chemicals include sodium bicarbonate, a common kitchen fire fighter, and more complex variations such as Super-K, Purple-K or Met-L-X for flammable metals (like copper, aluminum and iron).

This type of extinguisher uses foam to smother fires by creating a seal over the fuel, cutting off its oxygen supply. Foam extinguishers are typically rated for use on class A and class D fires. They can also be used on some class C fires, but not as effectively as a dry chemical agent. They can be aspirated or nonaspirated, with an aspirated model discharging the foam through an air-mixing branch pipe nozzle and nonaspirated models using a spray nozzle.

A dry-powder extinguisher contains a cylinder with a handle and a valve assembly that controls the release of the extinguishing agent. Some have a pressure gauge that’s color coded to show whether or not the device is pressurized properly. When the needle is in the green zone, it’s ready to use.

Most fire extinguishers require maintenance to ensure they’re ready for an emergency. You must inspect them monthly and record the date, month and name of the person who did the inspection. You should also shake the unit and replace it every few years, depending on the manufacturer’s instructions. Some fire extinguishers can be recharged after use, while others need to be replaced entirely if they’ve been discharged or damaged. For best results, place them where they can be easily accessed along evacuation routes. Installing a fire extinguisher in the wrong location can make it difficult to reach when you need it, or it may be blocked by furniture or equipment. To avoid these issues, you should always position them in easy-to-reach areas and mark their locations with a sign so they’re readily identifiable.