What is a Class A Fire – the best suited Fire Extinguisher?

Not enough people know that fire extinguishers come in different types but that they also are given a specific class which indicates the type of fires for which they are effective. Since life and property can depend on using the correct extinguisher on the correct type of fire, in this blog series, we will share explain the different classes of fire extinguishers and the types of fires they can handle.

What are Class A Fires?

Class A fires are ones involving ordinary combustible materials like wood, paper, textile, rubber and cloths. One of the easiest ways to recognise a Class fire is that its fuel sources leave ash behind when they burn.

Class A Fire Extinguisher | Types and Applications

Water: A water extinguisher’s purpose is to remove the heat from a fire, breaking the “fire triangle.” It is a simple solution for the simplest fire class, the Class A fire.

Foam: This extinguishing agent helps both to cool and suffocate fires and are also largely used for Class A fires.

Multipurpose Dry Chemical: Multipurpose dry chemical fire extinguishers are effective for Class A fires, as well as Classes B and C. The agent in these types interrupts the chemical reaction in the Fire Triangle (fuel, oxygen, heat plus a chemical reaction) to extinguish a Class A fire.
It should be noted that standard (BC) dry chemical fire extinguishers, using a sodium bicarbonate-based agent, are NOT effective on Class A, and are only intended for Class B and C fires.

Clean Agent: These extinguishers use halogenated, or “clean” agents, which avoid contamination of the area and are more environmentally friendly. This agent interrupts the chemical reaction and also cools the material to remove the heat element from the fire. Larger handheld models (11lbs and larger) can be rated for Class A fires, but smaller handheld models don’t contain enough agent to be rated for Class A.

Water Mist: A relatively new development, water mist extinguishers can also operate as a “clean agent” type, the mist avoids the types of water damage caused by a regular water extinguisher and is safe to use on live electric wires. This agent removes the heat from a fire and is primarily used as a Class A extinguisher and where a potential Class C hazard exists.

Certain types of extinguishers may be used on more than just Class A, such as the multi-purpose dry chemical extinguisher, while others are only ever classified as A, such as the water extinguisher.

It is vital that you use a fire extinguisher classified for the type of fire you are dealing with. Using a wrong fire extinguisher at best could prove ineffective, and at worst, could spread the fire or hazard (such as if a water extinguisher is applied to an oil fire or electrocute you if it is used on an electrical fire).