Foam fire extinguishers are one of the most common extinguisher types found in UK homes and workplaces. They work by smothering flammable liquid and flammable solid fires with a blanket of foam that cools the fuel and cuts off its oxygen supply. This guide covers what they’re used for, how they work, the colour code, how to use and store one safely, your servicing and legal obligations, and the important changes happening to foam chemistry right now.
There are five main types of fire extinguishers, each further classified into categories. These are foam, water, dry powder, CO2 and wet chemical.
In terms of foam, there are a further five types of fire extinguishers, which are Alcohol-Resistant Film-Forming Fluoroprotein (AR-FFFP), Fluoroprotein Foam (FP), Alcohol-Resistant Fluoroprotein Foam (AR-FP), Regular Protein Foam (P) and Film-Forming Fluoroprotein (FFFP) foam extinguishers.
Foam fire extinguishers, also known as Aqueous Film-Forming Foam (AFFF) extinguishers, are only suitable for putting out certain fire types. In this guide, we’ll be covering everything you need to know about foam fire extinguisher use, how they work, and more. Afterwards, you should be in a position to make an informed choice on whether you should have a foam fire extinguisher in your home or workplace.
TL;DR: What Is A Foam Fire Extinguisher?
Quick answer: Foam (AFFF) fire extinguishers tackle Class A (wood, paper, textiles) and Class B (flammable liquids such as petrol and diesel) fires. In the UK they carry a cream colour-coded label, commonly come in a 6-litre size, and must be serviced annually under BS 5306-3. They must not be used on electrical fires, cooking-oil (Class F) fires, or flammable-gas fires. Note that fluorinated AFFF foams are being phased out across the UK and Europe in favour of fluorine-free (F3) alternatives.
Foam Fire Extinguishers At A Glance
| Feature | Detail |
| Fire classes | Class A (solids) and Class B (flammable liquids) |
| UK label colour | Cream (on a red body) |
| Common sizes | 2 L, 3 L, 6 L (most common), 9 L |
| How it works | Forms a film/blanket that cools the fuel and smothers oxygen |
| Do NOT use on | Electrical equipment, cooking oils/fats (Class F), flammable gases (Class C) |
| Basic service | Annually, by an accredited technician (BS 5306-3) |
| Extended service | Every 5 years (discharge test) |
| Replace | At least every 10 years |
| Chemistry note | Traditional AFFF contains PFAS “forever chemicals” , being replaced by fluorine-free (F3) foam |
What Are Foam Fire Extinguishers Used For?
Buildings containing textiles, wood and other flammable solids, which can cause Class A fires, will usually require at least one foam fire extinguisher.
It’s also advisable to have a foam extinguisher handy if you’re using or storing flammable liquids. Petrol, kerosene, diesel, alcohol, and certain oils and greases can cause Class B fires, which foam fire extinguishers can also be used to tackle.
A foam fire extinguisher will usually deal with a fire involving burning liquid or flammable solids that isn’t yet out of control. You should never rely on any portable extinguisher to put out a fire that has already taken hold , evacuate and call the fire service.
Foam fire extinguishers are found in numerous factories, business premises and residential properties. All UK businesses are required by law to contain a minimum of two Class A extinguishers on every floor of their premises.
Foam extinguishers are found in factories, offices, warehouses, garages, hostels and residential properties, and are frequently sited alongside CO2 extinguishers so that both flammable-material and electrical risks are covered. Under the
Regulatory Reform (Fire Safety) Order 2005, the responsible person for a workplace must provide appropriate firefighting equipment based on a fire risk assessment; the type, size and number of extinguishers should follow the guidance in BS 5306-8.
Foam extinguishers come in several sizes, with the 6-litre model being the most common. The right size depends on the fire risk level of the premises; 2-litre, 3-litre and 9-litre options are also available.
What colour are foam fire extinguishers?
In the UK, every fire extinguisher has a predominantly red body, with a colour-coded band or panel identifying the contents. Foam extinguishers are identified by a cream label. This colour coding follows BS EN 3, so you can identify a foam extinguisher at a glance by its cream panel , useful when several extinguisher types are mounted together.
How Foam Fire Extinguishers Work
Foam fire extinguishers are more effective ways of dousing limited flames than your average water fire extinguisher. With a foam extinguisher, the Aqueous Film-Forming Foam goes some way to cooling the fire while also cutting off its oxygen supply.
This fire extinguisher foam comprises a mixture of Film-Forming Fluoroprotein, alcohol-resistant foams, film-forming foams, water and air. These counteract fires involving flammable solids and many burning liquids.
When you spray the foam onto the fire, it spreads over the flames to cool them and cut off their oxygen supply. By cutting off its oxygen, the fire can no longer sustain itself which causes it to die. With burning liquid fires, the foam from the AFFF fire extinguisher actually floats on the surface of the liquid. This action cools the liquid and makes extinguishing the fire easier.
Are Foam Fire Extinguishers Being Banned? (AFFF vs Fluorine-Free)
This is the most important recent change to be aware of. Traditional foam extinguishers use AFFF (Aqueous Film-Forming Foam), which contains fluorinated PFAS chemicals , so-called forever chemicals linked to environmental and health concerns.
Regulators across the UK and EU are progressively restricting them:
- Since 4 July 2025, foams containing PFOS, PFOA (C8) and PFHxS have been restricted in the UK.
- The Health & Safety Executive (HSE) ran a consultation on the wider use of PFAS in firefighting foams (closing February 2026), which will shape future restrictions.
- Broader bans on shorter-chain PFAS (C6) are anticipated toward 2030–2031, with staggered transition periods.
- The Fire Industry Association (FIA) advises organisations to begin transitioning proactively to fluorine-free foam (F3) extinguishers.
What this means for you: existing AFFF foam extinguishers are not yet outright banned and remain compliant for now, but if you are buying new or replacing units, consider fluorine-free (F3) foam to future-proof your site and reduce environmental liability.Speak to Chilman about a fluorine-free replacement plan.
Advantages of Foam Fire Extinguishers
Foam fire extinguishers are often used to control fires in both residential and business properties. They have a number of advantages, including:
- Safe for use: Aqueous Film-Forming Foam is non-toxic and hence safe for human use.
- Won’t make electrical fires worse: Even though foam extinguishers are not very effective or recommended for use on electrical fires, they are unlikely to cause the flames to intensify if sprayed directly onto combusted electrical appliances.
- Lower chance of damage: Foam from a foam fire extinguisher won’t likely cause damage to surfaces, although this cannot be guaranteed.
- Reduced chance of re-ignition: Foam fire extinguishers smother fires, meaning that chances of a fire re-igniting are minimal.
- Easier to use: A foam fire extinguisher is likely lighter than its water equivalent.
Disadvantages of Foam Fire Extinguishers
Although the advantages of a foam fire extinguisher are plentiful, there are also certain disadvantages attached to a foam extinguisher. These are:
- Not for Class C fires: Foam fire extinguishers work on Class A or Class B fires. Using a foam extinguisher on Class C to E fires could increase the volatility of any existing flames.
- Not suitable for use on electrical appliances: If you use foam fire extinguishers on electrical appliances experiencing electrical fires, it’s likely that the result could be negative. The chances are the fire will not be extinguished and the electrical appliances could be permanently damaged.
- Can’t be stored in cold places: A foam fire extinguisher could freeze if it is kept in conditions that are too cold.
- More expensive: A foam extinguisher will cost you more than a water fire extinguisher.
How to use a foam fire extinguisher (step by step)
Always assess whether it is safe to tackle the fire at all , if in doubt, evacuate and call 999. If it is safe to proceed:
- Pull the safety pin to break the tamper seal.
- Stand at a safe distance from the fire, foam extinguisher in hand or resting on a firm surface.
- Aim at the base of the fire, not the flames , point the hose at the burning material or the base of the burning liquid.
- For flammable-liquid fires, do not spray directly into the liquid (this can splash burning fuel). Instead, aim slightly above or at a nearby surface so the foam flows across and blankets the liquid.
- Squeeze the lever to discharge the foam.
- Sweep across the base until the fire is fully covered and smothered. Empty the extinguisher if needed , putting the fire out matters more than conserving contents.
- Watch for re-ignition and keep clear; have the extinguisher recharged or replaced after any use.
Never aim a foam extinguisher at a person, and never use one on a deep-fat fryer or cooking-oil fire. As a rule, do not use foam on electrical fires; if it is genuinely the only option to contain a blaze, keep at least one metre back to reduce the risk of electric shock.
How to store a foam fire extinguisher
Store foam extinguishers in an easily accessible, cool, dry and well-ventilated location, mounted on a proper bracket or stand. Avoid extremes of temperature: excessive heat can degrade the unit, and in winter the water-based contents can freeze and stop the extinguisher working, so keep them out of unheated outbuildings and exposed locations.
Maintenance and Inspection
Foam fire extinguishers must be maintained in line with BS 5306-3:
- Monthly visual check by the responsible person (in position, accessible, undamaged, pressure gauge in the green, tamper seal intact, instructions legible).
- Annual basic service by a competent, third-party-accredited technician (for example, a BAFE SP101-registered engineer).
- Extended service every 5 years, which includes a discharge test.
- Replacement at least every 10 years.
Chilman provides commercial fire extinguisher installation and maintenance and ongoing servicing to keep your site compliant.
Regulations, Standards and Employer Training Duties
Foam fire extinguishers are governed by BS 5306-3 (commissioning and maintenance) and BS EN 3 (construction and colour coding), with provision guided by BS 5306-8. Under The Regulatory Reform (Fire Safety) Order 2005, employers and responsible persons must inform, instruct and train staff on workplace fire precautions , including how to use the extinguishers provided. Chilman offers fire warden training, online fire safety training and fire risk assessments to help you meet these duties.
Need help with foam fire extinguishers?
Chilman supplies, installs and services fire extinguishers for businesses across Oxford, London and Bristol. Whether you need a routine service, a compliance check, or advice on switching to fluorine-free foam, get in touch for a free, no-obligation quote.
Use
There are different ways to use a foam extinguisher. Experts advise varying techniques of use depending on the type of fire you’re extinguishing. One fundamental step never changes though: always remove the safety pin before you do anything else!
After removing the foam extinguisher safety pin, follow the next steps to extinguish the fires you should be using foam extinguishers for. These are Class A and Class B fires that involve flammable solids and flammable liquids.
Remember to never aim a foam fire extinguisher directly at the flames when you extinguish flammable liquid fires or those that involve flammable solids. Rather, point the foam extinguisher hose towards the fire’s base where the burning liquid or combusting solids are. Don’t pick the foam fire extinguisher up; rather let it sit on the floor’s hard surface.
Make sure you’re at a safe distance from the blaze when releasing the foam by squeezing the lever on the foam extinguisher. You want to saturate the base of the fire with foam, covering it totally to cut off the fire’s supply of oxygen to smother it.
If you aim the fire extinguisher to spray foam over the top of the blaze, you’re wasting your time. In fact, with certain flammable liquids involved, you could end up making the fire worse.
Empty the extinguisher entirely if you need to. Your primary aim is to put out the fire, not to conserve the contents of the foam extinguisher so carry on spraying foam until the flames are gone. Because of the coating of foam, there’s very little chance of a fire re-igniting.
You shouldn’t, as a rule, try to extinguish electrical fires using a foam fire extinguisher. Sometimes, though, it may be the only way to contain the blaze. If you are going to use a foam fire extinguisher in this instance, keep at least one metre away from the fire while spraying. This way, the chances of ending up being electrocuted are significantly reduced.
Storage
You should store a foam fire extinguisher in an easily-accessible, cool and dry place with decent ventilation. Excessively high temperatures could lead to the decomposition of the carbon dioxide element. If this happens, the fire extinguisher will stop working. In winter, make sure the foam extinguisher isn’t too cold or its contents could freeze.
Frequently Asked Questions: Fire Extinguishers
What colour are foam fire extinguishers?
Foam extinguishers have a red body with a cream colour-coded label or band, in line with BS EN 3. The cream panel lets you identify them quickly when several extinguisher types are mounted together.
What fires can a foam extinguisher be used on?
Foam extinguishers are suitable for Class A fires (wood, paper, textiles and other solids) and Class B fires (flammable liquids such as petrol, diesel and alcohol). They are not for electrical, cooking-oil (Class F) or flammable-gas fires.
Can you use a foam extinguisher on an electrical fire?
No, foam extinguishers are not designed for live electrical fires , use a CO2 extinguisher instead. If foam is the only available option to contain a blaze, stay at least one metre back to reduce the risk of electric shock.
Are foam fire extinguishers being banned in the UK?
Not outright , but fluorinated AFFF foams are being progressively restricted because they contain PFAS “forever chemicals.” Certain PFAS (PFOS/PFOA/PFHxS) have been restricted since July 2025, with wider restrictions expected toward 2030–31. Fluorine-free (F3) foam is the recommended replacement for new purchases.
How often should a foam fire extinguisher be serviced?
A basic service is required annually by an accredited technician under BS 5306-3, with an extended (discharge) service every five years and replacement at least every ten years. A visual check should also be done monthly.
What size foam fire extinguisher do I need?
The 6-litre foam extinguisher is the most common, but the right size and number depend on your premises’ fire risk assessment and the guidance in BS 5306-8. Options include 2, 3, 6 and 9-litre models.
What’s the difference between foam and AFFF extinguishers?
“Foam extinguisher” is the general term; AFFF (Aqueous Film-Forming Foam) is the most common foam type. Newer fluorine-free (F3) foams perform a similar job without the PFAS chemicals found in AFFF.