Fire extinguishers are one of the best tools that homeowners have to control small fires before they become a major catastrophe. However, they only work if they are used correctly. A little advance knowledge of the different types and how they operate is essential. A few simple steps can make the difference between success and failure.
Most household fire extinguishers are stored pressure types (sometimes called cartridge operated or hand-held units). These have a metal container with a hose attached that contains the actual firefighting agent. When a user pulls the pin on the handle or lever, it depresses an operating lever, which opens a passage through the valve and releases the firefighting agent. A user should point the nozzle of the hose low at the base of the fire, not directly at the flames; doing so will discharge the extinguishing agent and allow it to penetrate into the fuel source, rather than just blow the fire around the room. After aiming at the base of the fire, the user should sweep the nozzle from side to side to distribute the fire-suppressant mixture.
The simplest of these extinguishers is usually the carbon dioxide model, which has a small cartridge that is filled with compressed carbon dioxide gas. The carbon dioxide, when discharged from the nozzle of the hose, forms a blanket that smothers the fire by blocking the oxygen supply and cutting off the fuel flow. This is particularly effective against Class A, wood and paper fires; class B, flammable liquids such as gasoline, oil and paint; class C, electrical equipment fires; and class D, metals such as sodium and magnesium.
Another type of fire extinguisher uses a pressurized metal cylinder containing water with some other additives, usually salt or potassium bicarbonate or monoammonium phosphate. The additions help the water penetrate deeper into the burning fuel and cling more to steep surfaces. When the hose is pointed at the base of the fire, squeezing the handle or lever will discharge the water. After the fire is out, it is important to move back a safe distance and keep an eye on the area to make sure it does not re-ignite.
The operating instructions for any fire extinguisher should be thoroughly read and reviewed regularly. This is especially important for children and babysitters, who should be familiar with the proper use of the fire extinguisher in case a home fire should occur. If you own a business or other commercial property, it may be wise to hire an experienced fire protection service company to periodically inspect and service your fire extinguishers and provide instruction in their use to employees and clients. Keeping your fire extinguishers easily accessible in the locations where they are most likely to be needed, along with a well-practiced escape plan, can greatly increase your chances of saving your home or business from a catastrophic event.