How to Use a Fire Extinguisher
Using a fire extinguisher is fairly simple and can be done by anyone regardless of whether or not they have been trained. All fire extinguishers operate in a similar way regardless of the extinguishing agent inside, although different methods can be used. In this guide we aim to explain how to use a fire extinguisher.
In an emergency situation, wherever possible, the instructions for how to use a fire extinguisher should be read. Of course, this is not always possible, which is why a certain level of training in extinguisher use is recommended.
The ability to use an extinguisher can give a person precious time to escape, and also reduces the level of fire damage.
So how to use a fire extinguisher?
The basic method in the form of an acronym is the ‘PASS’ method. This is broken down into four steps.
Firstly, Pull the pin at the top of the extinguisher. This releases the lock on the canister which allows the agent to be deployed.
Secondly, Aim the extinguishing agent at the base of the fire. This is important since the easiest way to extinguish a fire is to tackle the fuel.
Then Squeeze the level on the canister slowly. This allows the extinguishing agent to be released through the nozzle of the canister. Obviously once the level is not compressed, the agent will cease to flow.
Finally, Sweep the hose of the extinguisher from side-to-side until the fire is completely extinguished. A fire extinguisher should always be operated from a safe distance away. Before leaving the fire, the user should always be confident that the fire has been put out, or professional fire-fighters have taken over.
The PASS method is primarily designed for water fire extinguishers, and although this route is still useful for other extinguishing agents, some other methods are occasionally more effective. This usually depends on the extinguishing agent itself and the fuel involved in the fire.
When operating a powder fire extinguisher, the area where the nozzle is aimed at varies according to the fuel involved. For solid materials and electrical equipment (once the power has been shut off for the latter), the PASS method is adequate. For spilled liquids, the hose should be aimed at the near edge of the fire and a rapid sweeping motion used to drive the fire towards the far edge. Where the liquid is flowing, the hose should be directed at the base of the fire and swept upwards to contain the flow.
With foam fire extinguishers, for solid combustibles the PASS method is sufficient. However for flammable liquids, the extinguishing agent should not be aimed at the fire itself, but at a vertical surface near the fire. This is because the fire can be too easily encouraged to spread. Using this method means the foam can effectively smother the fire.
CO2 fire extinguisher are best deployed using the PASS method, however note that the horn should not be held during use as this becomes cold during use and can cause frost burns.
Finally, when operating a wet chemical fire extinguisher, which looks different to most other types, the fine spray of the chemical should be used in slow circular movements, which allows the agent to fall gently and reduces the chance of hot oil splashback onto the user.