How to Use a Fire Extinguisher

Having an appropriately sized fire extinguisher available can mean the difference between control and chaos in the event of a small- to medium-sized fire. Familiarizing yourself with the different types of fire extinguishers, and how to use them, will prepare you for a safer and more effective response when an emergency occurs.

Before using a fire extinguisher, make sure the fire is safe to fight. If the fire is large, uncontrolled, or producing heavy smoke, it is best to evacuate the area and call the fire department rather than attempt to combat the blaze yourself. Remember, most people who die in fires do so from smoke inhalation.

Pull: Aiming at the base of the fire is important. Aiming directly at the flames will cause them to blow around and spread, which can make the fire even harder to extinguish. Instead, aim low at the base of the fire, squeezing the handle or lever to discharge the contents of the extinguisher. Sweep: After aiming and squeezing, move the nozzle of the fire extinguisher from side to side over the base of the fire, smothering it until all signs of flames are eliminated. Once the nozzle of the fire extinguisher is swept over the base of the flames, it’s a good idea to keep it moving in this manner until all the fire has been completely put out.

CLASS A – WATER

Water is the most basic and effective fire extinguisher for putting out class A fires. This type of extinguisher uses air under pressure to release the water that is directed with a hose or nozzle at the fire’s source. The water’s heat-absorbing properties help to cool the fuel below its ignition point, interrupting the combustion cycle and thereby extinguishing the fire.

CLASS B – FLAMMABLE LIQUIDS

Class B fires involve liquids, which can be difficult to fight with powder or dry chemical extinguishers. Class B fire extinguishers use a specialty formulation of sodium bicarbonate and silica gel, which are designed to interrupt the chain reaction of the fuel by absorbing the fuel particles and preventing their contact with oxygen. This type of fire extinguisher can also be used on combustible liquids that generate heat such as oil or grease.

CLASS C – ELECTROMAGNETIC CHARGE

Unlike classes A and B, class C fires are caused by electrical equipment or wiring. These can be dangerous to fight because they often produce high temperatures, causing electrical shock or melting and shorting out electrical circuits. A class C fire extinguisher contains potassium carbonate, a chemical similar to sodium bicarbonate. When applied to a class C fire, it creates a foam or coating over the fuel, smothering it and cutting off its supply of oxygen.

When using a fire extinguisher, be sure to maintain a safe distance of 6 to 8 feet between you and the flames to ensure your safety. Also be sure to inspect the fire extinguisher periodically, making sure it’s within its functional range and that it has not been used, as this could contaminate its contents and render it ineffective. Look for a tamper seal, pin, and pull tag. A tamper seal or missing pin indicates the unit has been used and may require professional evaluation. It is also important to check the fire extinguisher’s pressure gauge, as a reading below this functional range may indicate that it is empty and should be recharged.