What are the most common fire extinguishers?

There is an ever-growing list of fire extinguishers across the UK and the wider world. The most common 5, to the UK are:


  1. Water

  2. Foam

  3. Dry Powder

  4. CO2

  5. Wet chemical


However, to appropriately understand each type of fire extinguishers, it is first necessary to understand why they work, if used for the correct type of fire.


To understand this, we can use the Fire Tetrahedron.[1]

The fire tetrahedron, a 3D representation of the relationship between heat, oxygen, fuel, and chain reactions in creating and continuing fires.

Put simply, the Fire Tetrahedron is a pictorial representation of the elements needed to ignite and sustain a fire,


  • Heat,

  • Oxygen,

  • Fuel, and

  • The ensuing exothermic chain reaction.


The exothermic chain reaction provides heat, and therefore aids in the continuation of the fire.


Fire extinguishers are developed to remove one side of the fire tetrahedron, which will cause fires to stop burning, due to a lack of one or more of these essential components.


1. Water Extinguishers


A fire extinguisher with a red label, to show it is a water type extinguisher













Water Extinguishers[2] have a red label and if utilised correctly remove the heat element of the fire tetrahedron.


This extinguisher can be used on Type A fires, named Ordinary Combustible, which include:

  • wood,

  • card,

  • paper,

  • textiles, and

  • plastics.


This type of extinguisher is common and should be stored for use in buildings such as:

  • offices,

  • schools and nurseries,

  • hospitals,

  • domestic dwellings, and

  • warehouses.



2. Foam Extinguishers



A fire extinguisher with a cream label, to show it is a foam type extinguisher













Foam extinguishers feature a cream label and work by removing heat and separating oxygen from other elements within the fire.


This type of extinguishers can be used on Type A Ordinary Combustible, and Type B Flammable Liquids.

Foam extinguishers work on all Type A materials, and Type B materials including:

  • gasoline,

  • kerosene,

  • grease,

  • oil,

  • paints,

  • turpentine, and

  • flammable gases.


Type B fires reach maximum intensity very quickly, and as such require rapid extinguishment to limit damage and further spread.


This type of extinguisher should be at hand for premises such as,

  • offices,

  • schools and nurseries,

  • hospitals,

  • domestic dwellings, and

  • warehouses.

  • Also, garages,

  • workshops, and

  • sheds, etc.


It’s fair to say that the vast majority of buildings need either water or foam extinguishers.[3]


3. Dry Powder Extinguishers



A fire extinguisher with a blue label, to show it is a dry powder type extinguisher













Sometimes named ABC extinguishers, Dry Powder extinguishers can be used on Type A, B & C fires, and have a blue label.


It works by separating the fuel from oxygen, thus removing the chance for further combustion. As such, it is also suitable for Type D and Electrical Fires.


Type C Flammable Gases, including:

  • propane,

  • butane,

  • methane,

  • natural gas, and

  • hydrogen.


Type D Flammable metals, including:

  • magnesium,

  • potassium,

  • lithium, and

  • sodium.


Electrical fires, including electrical equipment up to 1000V, including:


  • appliances,

  • wiring,

  • circuit breakers, and

  • outlets.

  • As well as Type A and B materials.


It is important to remember to turn off the mains electricity if you can while fighting a fire that concerns electrical items, and ensure it is not used in an enclosed space, as it is very easy to breathe in the powder once it is expelled.


This extinguisher can be used interchangeably for all Type A, B, C and electrical fires.


Similarly, specialist dry powder extinguishers can also be used for fires involving flammable metals, such as magnesium, titanium, potassium, and sodium.


This type of extinguisher should be used in any of the Type A or B locations, alongside,

  • businesses using flammable gases

  • flame cutting, or welding workshops,

  • garage forecourts, and

  • buildings with large boiler rooms.


4. CO2 Extinguishers

A fire extinguisher with a black label, to show it is a CO2 type extinguisher














CO2 extinguishers work by removing oxygen from the combustion process and feature a black label.

They also have a different shaped horn, which can get incredibly cold during use, so you should not hold it. If you do, then you run the risk of receiving cold burns and will probably cause you to drop the extinguisher.


The CO2 extinguishers is used for Class B and electrical fires, so predominantly flammable liquids and electrical equipment.


As such, the CO2 extinguisher is most utilised in,

  • office blocks,

  • commercial kitchens,

  • server rooms, and

  • building sites.

Similarly, all work vehicles should also carry a 2kg CO2 extinguisher.[4]




5. Wet Chemical Extinguishers

A fire extinguisher with a yellow label, to show it is a wet chemical type extinguisher




























This extinguisher features a yellow label and works as part of a two-step process.


Firstly, it removes heat from the fire, by using a wet chemical composition that is sprayed onto the base of the fire. Secondly, it creates a barrier between the oxygen and fuel, thereby stopping reignition.


They are applicable for Class F fires, which involve fats, grease, and cooking oils.


As such, they are applicable in many industrial cooking locations, including,

  • professional kitchens

  • chip shops, or other takeaway shops,

  • restaurants, and

  • canteens.


Another key piece of fire fighting equipment is the fire blanket, which can be used in fires involving cooking oils.


Chart showing which colour extinguisher is suitable for each fire type.

As with all fire situations, building users must be suitably trained to utilise fire extinguishers correctly.


Although simple to use in theory, when in an emergency the body produces adrenaline. Although this is very useful, it can make individuals clumsy, resulting in improper use of fire extinguishers.


The top tip for fire extinguisher use is to follow the PASS method and to squeeze the handle at the base of the fire until the fire is out, or the extinguisher is empty.[5]

After this point, the individual should leave the premises and stay out.


Inforgraphic about the PASS method, Pull, Aim, Squeeze, and Sweep.

Here in the Adexon offices we have a CO2 extinguisher close at hand, ready for use in the office, alongside a fire blanket for use in the kitchen.


What fire extinguishers do you have in your place of work? Would you consider buying one for your home?


Let us know in the comments!


__________________________________________________________________________ [1] Image released into the public domain. [2] All fire extinguisher images are taken from Surrey Fire and Safety Limited, ‘Fire Extinguisher Colours explained in a simple up-to-date guide,’ <https://surreyfire.co.uk/fire-extinguisher-colours/> 19/04/2022 [3] Surrey Fire and Safety Limited, ‘Fire Extinguisher Colours explained in a simple up-to-date guide,’ <https://surreyfire.co.uk/fire-extinguisher-colours/> 19/04/2022 [4] Surrey Fire and Safety Limited, ‘Fire Extinguisher Colours explained in a simple up-to-date guide,’ <https://surreyfire.co.uk/fire-extinguisher-colours/> 19/04/2022 [5] Image from Fire Extinguisher Depot, ‘How to use a fire extinguisher,’ <https://fireextinguisherdepot.com/how-to-use-a-fire-extinguisher/> 19.04.2022

9 views0 comments