The complete guide to different fire extinguishers

A crucial aspect of fire safety is knowing which of the different fire extinguishers can be used to tackle different classes of fire – and which types potentially risk making certain fires worse because of their unsuitability. Knowing which type of fire extinguisher is suitable for each class of fire can not only protect lives and property, it’s a legal obligation. Premises without adequate and relevant fire safety equipment will fail to comply with the Regulatory Reform (Fire Safety) Order 2005. 

Conducting a fire risk assessment is the only way to highlight fire hazards and risks in a building, which will then inform how many different fire extinguishers are required in the premises. Here, we outline which types of fire extinguishers may be needed, and the fire classifications they’re designed to extinguish.

Colour labels for different fire extinguishers

Different fire extinguishers tackle different classes of fire in their own specific way, so it’s important that each one can be quickly identified by a colour-coded label. These can be found at the top of the fire extinguisher to show its type and contents.

• Black: CO2 fire extinguishers
• Cream: Foam fire extinguishers and MultiCHEM fire extinguishers
• Blue: Powder fire extinguishers
• Red: Water fire extinguishers and water mist fire extinguishers
• Yellow: Wet chemical fire extinguishers

Different fire extinguishers for different fire classes

Different fire extinguishers are designed according to the different fuels which start fires, categorised into groups A, B, C, D, F, and Electrical. It’s the presence of these fuels within a premises or business that will determine the most suitable fire extinguisher needed.

Water fire extinguishers

Of all the different fire extinguishers used in the UK, water fire extinguishers are the most common. Being water-based, they work by cooling the fuel and ensuring it burns at a much slower pace until the fire is extinguished. 

Best used for: Class A fires, which include fires caused by flammable solids such as textiles, coal, wood, cardboard, paper, and fabrics. 

Premises used in: Most premises are required to have a water or foam fire extinguisher, so they’re often found in busy places like offices, schools and hospitals. With a low-cost price, ease of maintenance, and the fact they’re an environmentally friendly option, it’s easy to see why water fire extinguishers are a preferred choice for many businesses.

Do not use for: Any fires involving electrical equipment, kitchen fires, or fires caused by flammable liquid or gas.

CO2 fire extinguishers

A CO2 fire extinguisher contains pure carbon dioxide and works to suffocate the fire by removing the oxygen element of the fire triangle needed to burn. It also helps remove heat, thanks to its cold discharge.

Best used for: In the hands of a trained user, a CO2 fire extinguisher can be used for some Class B fires (flammable liquids like petrol or oil, but never on cooking fires) as well as electrical fires, since CO2 fire extinguishers are non-damaging to electrical equipment and machinery.

Premises used in: CO2 fire extinguishers are suitable for premises that use electrical equipment, including modern offices, technology stores, and server rooms.

Do not use for: Any fires involving combustible materials such as wood and textiles, burning metals, flammable gases, or cooking oils and fats. CO2 fire extinguishers should never be used on cooking fires due to the powerful discharge released, which can easily splash burning fat and fan the fire.

Foam fire extinguishers

Foam fire extinguishers perform a cooling function and quickly smother burning materials, while the foam agent helps prevent the fire reigniting. 

Best used for: Most commonly used on Class B fires (flammable liquids, petrol and spirits), although they’re also a recommended choice for Class A risk areas (those featuring combustible materials such as wood and paper). 

Premises used in: Ideal for office environments, hospitals, schools, and other spaces where organic materials play a large role in the landscape.

Do not use for: Foam fire extinguishers shouldn’t be used on kitchen fires, fires involving burning metals, or those with an electrical source. 

MultiCHEM fire extinguishers

Of all the different fire extinguishers, MultiCHEM fire extinguishers are among the most versatile. Thanks to its multi-class, high-performance abilities and 34A rating (the industry’s highest for a six-litre fire extinguisher), the MultiCHEM ABF-rated fire extinguisher can tackle sizable fires.

Best used for: As the name suggests, the MultiCHEM ABF-rated fire extinguisher is ideal for Class A, B, and F fires. These include flammable liquid fires with large quantities of fuel and surface areas, combustible materials such as wood, paper, and textiles, as well as deep fat fryer fires. 

Premises used in: Perfect for big kitchens using deep fat fryers. With contemporary designs in silver, gold, and antique copper, modern bars and restaurants as well as luxury hotels and offices can complement design schemes while having innovative fire safety equipment on hand. Instead of purchasing various different fire extinguishers for the same building, MultiCHEM fire extinguishers are truly versatile for sites with multiple applications, such as universities, communal living areas, and care homes. 

Do not use for: Any fires involving burning metals, flammable gases such as propane or butane, or those caused by an electrical source.

Powder fire extinguishers

A dry powder fire extinguisher can tackle multiple classes of fire. This type of fire extinguisher smothers fires by producing a thick barrier between the fuel and the source of oxygen. 

Best used for: Known as ‘ABC’ fire extinguishers, powder fire extinguishers can be used on Class A (combustible materials), Class B (flammable liquids) and Class C (flammable gases) fires. They can also be used for fires with electrical sources up to 1000v. 

Premises used in: Since powder fire extinguishers should not be used in confined spaces, they’re best used in premises such as garage forecourts, commercial boiler rooms, and workspaces that use welding.

Do not use for: A powder fire extinguisher shouldn’t be used in enclosed spaces because the powder can easily be inhaled and it leaves a residue that can be difficult to clean up. 

Water mist fire extinguishers

The versatile water mist fire extinguisher is an environmentally friendly choice. It provides intense cooling to the fire with a mist curtain, cutting off the supply of oxygen and suffocating the flames. 

Best used for: Class A (combustible materials) and Class F (cooking oils and fats) fires.

Premises used in: An ideal option for a number of different settings, including commercial kitchens, schools and factories. Since the contents aren’t harmful to a building or property, water mist fire extinguishers are also suitable for historical sites such as museums and churches.

Do not use for: Any fires involving electrical equipment, burning metals, or fires caused by flammable liquid or gas. 

Wet chemical fire extinguishers

A wet chemical fire extinguisher works by creating a layer of foam on the burning oil or fat, stopping the supply of oxygen so the fire isn’t fueled any further.

Best used for: Specifically designed for use on Class F fires (cooking oils and fats). 

Premises used in: The perfect solution for the demands of commercial kitchens and canteen environments, where cooking fats and deep fat fryers are in high usage.

Do not use for: Any fires involving electrical equipment, burning metals or fires caused by flammable liquid or gas.

For a quick-reference resource on different fire extinguishers, download our free CheckFire Fire Extinguisher Guide – a simple visual that illustrates the types of different fire extinguishers and which is best suited to each class of fire. To find out more about fire extinguisher legislation and other useful fire safety news, visit our resource centre or sign up to our newsletter.