When it comes to the types of fire extinguishers, there are five main types including wet chemical, CO2, dry powder, foam and water. In order to meet the current regulations, it is important for you to have the exact type of fire extinguisher that is needed for your premises. The need for different types of fire extinguisher arises from the different types of fuel that may start a fire. The different types of fires caused by different fuels are classified as different classes of fire. As far as the type of fire extinguisher needed at your business premises is concerned, it depends on the fire risk from various classes of fire.
It is important for you to ensure that the right size and weight of fire extinguisher is available at your business premises to meet the fire safety regulations.
Even though extinguishers are commonly grouped into five main types, some — particularly water and dry powder — are available in specialist variants. This means there are multiple extinguisher designs used in practice, including standard and specialist dry powder, foam, water spray, water mist, wet chemical, and carbon dioxide. There is no single fire extinguisher that can be used on all classes of fire.
Here is a brief summary of different fire classes along with a reference chart displaying the type of extinguisher for each glass of fire. We also share detailed explanation of different types of fire extinguishers below.
Classes of fire
There are several recognised fire classes, defined by the type of fuel involved. In the UK and Europe, these are typically classified as Class A, B, C, D, and F. Fires involving electrical equipment are not assigned a separate fire class, but require appropriate extinguishing methods while the equipment remains energised.
The recognised fire classes are:
- Class A – fires caused by combustible materials including paper, fabric, wood and other flammable solids.
- Class B – fires caused by flammable liquids such as paint, turpentine or petrol among others.
- Class C – fires caused by flammable gases including methane, butane or hydrogen among others.
- Class D – fires caused by combustible metals including potassium, aluminium or magnesium among others.
- Class F – fires include those caused by cooking oils such as a chip-pan fire.
- Electrical Fires (Not a Fire Class) – fires involving electrical equipment but upon removal of the electrical item, the fire class is changed.
Types of Fire Extinguishers
Foam Extinguishers
These are the most common type of fire extinguishers used for class B fires. However, these are water-based which means they these can also be used for class A fires. The label colour is cream.
These fire extinguishers may be used for fires caused by various organic materials including wood, coal, textiles, fabrics, cardboard and paper among other things as well as flammable liquids including petrol and paint.
This type of fire extinguisher should not be used for fires caused by flammable metals, kitchen fires and fires that involve electrical equipment.
Foam extinguishers should not be used on live electrical equipment and should always be selected based on the findings of the fire risk assessment.
How This Extinguisher Works
These extinguishers work by creating a cooling effect on the fuel that is responsible for causing the fire. When it is poured on burning liquid, the fire is extinguished by creating a barrier between the fuel and the flame with the help of the foaming agent.
Foam extinguishers are needed by business and premises where the building is made from various organic materials or in buildings where such organic materials are likely to be found including warehouses, residential properties, hospitals, schools, offices and buildings storing flammable liquids. In simple terms, most of the buildings require the presence of foam or water extinguishers.
Location
This type of extinguisher should be placed by the exits on floors that have been identified as a fire risk for class A or class B.
Water Extinguishers
Water extinguishers are mostly used for class A fire risk. In most premises, it is necessary to have either foam or water extinguishers. It has a bright red label.
This type of extinguisher is used for fires caused by various organic materials including fabrics, textiles, coal, wood, cardboard and paper among others. It should not be used for kitchen fires, fires caused by flammable gas and liquids as well as fires that involve electrical equipment.
How This Extinguisher Works
As far as the inner working is concerned, a water extinguisher works by having a cooling effect on the liquid that causes the burning fuel to burn at a slower rate until the flames are completely extinguished.
The type of businesses or premises where these extinguishers are needed include buildings made of wood or organic materials or business premises containing certain types of organic materials such as hospitals, schools, offices, warehouses and residential properties. Most of the buildings require either foam or water extinguishers.
Location
These extinguishers are required to be placed by the exit on floors that have been identified for class A fire risk.
What’s different about water spray extinguishers?
This type of extinguisher comes equipped with a spray nozzle instead of a jet nozzle which means the water is able to cover much greater surface area quickly in order to put out fire more rapidly.
What’s different about water mist extinguishers?
As the name suggests, this type of extinguishers come equipped with a different type of nozzle that is responsible for releasing extremely small, microscopic water particles. This extinguisher nozzle releases micro particles that suffocate the fire and also keep the person using the extinguisher safe by creating a wall of mist which helps in reducing the feeling of heat.
Water Mist Extinguishers (Modern Applications)
Water mist extinguishers are increasingly used as a multi-risk solution, as they can be effective on Class A fires and, in certain designs, safe for use on live electrical equipment. They are often specified where environmental impact, user safety, or clean-agent alternatives are required.
Certain water mist extinguishers are specifically tested and approved for use on live electrical equipment at defined voltages. This must always be confirmed by manufacturer certification and the fire risk assessment.
Dry Powder Extinguishers
The standard dry powder extinguishers are also known as ABC extinguishers as these can be used for class A, class B and class C fires. However, these should not be used in enclosed spaces as the dry powder in the extinguisher can be easily inhaled. Also, it’s not easy to clean up the leftover residue once the fire is over. These can also be used for fires involving electrical equipment. There are also special dry powder extinguishers that are typically used for fires caused by flammable metals. The label colour for this type of extinguisher is blue.
This type of fire extinguisher may be used for fires caused by various organic materials including wood, coal, textiles, fabrics, cardboard and paper among others. It may also be used for fires caused by flammable liquids including petrol and paint as well as flammable gases including acetylene and liquid petroleum gas. Any fires that involve electrical equipment up to 1000 V may also be dealt with the help of this fire extinguisher.
As mentioned above, there are special dry powder extinguishers but these are typically used only on flammable metals such as magnesium and titanium.
This type of fire extinguisher should not be used for fires that involve electrical equipment over 1000 V and fires that involve cooking oil.
Dry powder extinguishers are generally unsuitable for enclosed spaces due to inhalation risk and poor visibility during discharge.
Location
Garage forecourts, welding and flame cutting businesses and buildings with large boiler rooms are examples of premises using flammable gases for chemical processes where this type of fire extinguisher is required.
Wet Chemical Extinguishers
Wet chemical extinguishers are designed for use on Class F fires, involving cooking oils and fats. They can also be used on Class A fires although it is more usual to have a foam or water extinguisher for this type of fire risk
For fires involving cooking oils and fats (a Class F fire), a wet chemical extinguisher can be used. The wet chemical fire extinguisher can also be used on Class A fire, but foam or water extinguishers are more common. Dry powder extinguishers smother fires by forming a barrier between the fuel and source of oxygen. The label colour for this type of extinguisher is yellow.
Wet chemical extinguishers can also be used for fires caused by various organic materials including wood, coal, textiles, fabrics, cardboard and paper.
Location
This type of fire extinguisher needs to be placed near to the source of the fire risk in commerical kitchens and canteens.
Carbon Dioxide (CO2) Extinguishers
CO2 extinguishers are mainly used for electrical fire risks and are usually the main fire extinguisher type provided in computer server rooms. They also put out Class B fires. CO2 extinguishers suffocate fires by displacing the oxygen the fire needs to burn. This type of extinguisher has a black label.
Location
CO2 extinguishers need to be place near to the source of the fire risk or near the fire exits such as offices, kitchens, server rooms and premises with electrical appliances and equipment.
Fire Extinguishers and UK Fire Safety Law
In the UK, fire extinguishers are not prescribed by type or quantity in legislation. Under the Regulatory Reform (Fire Safety) Order 2005, the Responsible Person must provide appropriate fire-fighting equipment where necessary, based on the findings of a fire risk assessment.
British Standard BS 5306-8 provides recognised guidance on the selection, installation, inspection, and maintenance of portable fire extinguishers. While not law, it is widely used by enforcing authorities when assessing compliance.
Our Services
For UK premises, extinguisher provision, servicing, and placement should always be based on a fire risk assessment and maintained in line with recognised guidance.
If you are in need of fire extinguisher servicing, our accredited fire engineers will attend your sites at a time convenient to you. Contact us today to arrange a visit and decide on the future course of action.
