It's All About Class

Improving the fire safety of your workforce is of paramount importance as per Australian Standards 1851 (AS 1851). Having multiple precautions in place such as regularly tested fire alarms, approved fire doors, risk assessed escape routes and adequate fire extinguishers is all well and good, and should be a part of any working environment. However employees need to know how these things work. Fire extinguishers are the one component which might require staff training before using, as making use of the right extinguisher is an important thing to consider. This guide will help you to understand how some of the extinguishers are different and where they should be used.

Different Classes

Fires are split into different classes, with each class requiring a different extinguisher to tackle it. It's important that each of these classes is fully understood, as some extinguishers can be used for different types of fire, whereas others are specifically designed for certain situations. Using the wrong one can result in fatal injuries. It's easy to know which extinguisher is which as they will be colour coded and clearly labelled. 

Class A

Water extinguishers are the most common ones available. They use water and are perfectly safe to use on what many would consider to be common fires (class A) involving paper and wood. They absolutely cannot be used on electrical or flammable liquid fires, as the water will conduct the current and cause an explosion of fire. This is why throwing water onto a chip fat fire is very dangerous.

Class B

Class B fires involve flammable liquids such as paint and fuel. Foam extinguishers are great here as the foam covers the gases that escape and choke the fire. CO2 extinguishers and dry powder ones can also be used here. They all work on the principle of removing an aspect of a fire. Every fire needs fuel, oxygen and heat to burn, yet if you remove one of these components, it will die out.

Class C

These fires are caused by flammable gases, so directly spraying the ground won't work. CO2 extinguishers are used here as the gas itself dissipates and puts the fire out, limiting its ability to spread through the air by blocking the fuel's access to oxygen. 

Class D

Class D fires are caused when flammable metals catch alight. Dry powder extinguishers are used here and work by cooling the fire or by separating the oxygen from it. They are specialty tools and will not work on other fires.