A fire extinguisher can save lives, but only if you know how to use it. Too often, people rely on their fire extinguisher as a tool to rearrange the sock drawer or their garage, rather than as an active defense against fires. Fires can double in size every 60 seconds, so it’s essential that you take the time to learn and practice the proper method of operation before a real emergency occurs.
All fire extinguishers are required to have usage instructions printed on them, and it’s important that every able-bodied member of your household read and understand these. However, in the panic of a fire, it’s easy to forget these instructions and make mistakes that can be fatal. That’s why the fire department recommends the ‘PASS’ system: Pull, Aim, Squeeze and Sweep.
Pull the pin, which is usually attached to a plastic or metal ring, located between the handle’s two sections. This will break the seal and begin decompression, which will allow the pressure inside to build up to a safe level for discharge. This takes about 10 to 15 seconds, so be prepared to act fast.
Aim the nozzle or hose at the base of the fire. Never aim directly at the flames, as this can actually fuel the fire, causing it to grow larger and more dangerous. Blasting the fire with the hose or nozzle also won’t work; instead, you must sweep the nozzle from side to side over the area of the fire to effectively extinguish it.
For solids (A), fire a powder or dry chemical extinguishers work by smothering the fire and cutting off its oxygen supply, which in turn stops the chemical chain reaction that sustains it. If the fire is in a container or over flammable liquid (B), foam can be used to break down the interaction between the flames and the liquid surface. For polar flammable liquids such as alcohol or glycol, specialized AFFF (aqueous film forming foam) extinguishers are available.
For electrical fires (C), a water, carbon dioxide or wet chemical extinguisher works by discharging a layer of suppressant on the burning wires, which stop them from conducting electricity and thus stopping the fire. The water is usually only useful for small appliances such as chip pans, and the wet chemical and CO2 extinguishers are best for larger electrical equipment. Halon gas is used in some smaller extinguishers, but it was banned from new production in 1994 under the Montreal Protocol due to its ozone depletion and long atmospheric lifetime. Instead, most new extinguishers are filled with either pressurized nitrogen or pressurized carbon dioxide. These are cheaper and easier to refill. If you’re not sure which type of extinguisher you need, consult a fire safety professional. They can recommend an appropriate model and help you test it to see which one will do the job properly. In addition, they can recommend an appropriate place to have your fire extinguisher recharged or replaced if necessary.