Foam fire extinguishers remain one of the most versatile and widely used items of fire safety equipment, especially when it comes to tackling Class A (flammable solids) and Class B (flammable liquids) fires.
This guide is your go-to resource for understanding the different types of foam extinguishers, how they work, and where they should be used.
What Are Foam Fire Extinguishers & How Do They Work?
Foam extinguishers work by having two effects on a fire. The water content in the foam cools the fire, while the foam component forms a film over flammable liquids to smother vapours and prevent re-ignition.
Foam extinguishers are ideal for tackling:
- Fires involving solid combustibles (wood, paper, textiles)
- Fires involving flammable liquids (petrol, paints, solvents)
Types of Foam Extinguishers: AFFF, AR-AFFF & PFAS-Free
There are several types of foam extinguishers, each suited to different environments and fire risks.
AFFF (Aqueous Film-Forming Foam)
The most common type, AFFF extinguishers, use fluorinated surfactants to create a film over liquid surfaces. AFFF extinguishers are very effective, but are reliant on the use of PFAS chemicals. One of the PFAS chemicals that used to be used a lot in AFFF foams, PFOA, is now restricted under new UK regulations.
AR-AFFF (Alcohol-Resistant AFFF)
Used in settings where polar solvents are present, these extinguishers form a tougher barrier to prevent alcohols from breaking through the foam layer. These extinguishers serve a specific fire risk that a normal foam extinguisher can't tackle.
PFAS-Free Foam (also known as Fluorine-Free Foam)
The latest generation of foam extinguishers, such as Firechief® PureSafe, are fluorine-free and fully compliant with current legislation, whilst also being the proactive option for those looking to the future. They offer the same fire performance without the environmental trade-off.
Where Should Foam Extinguishers Be Used?
Foam extinguishers are highly adaptable and commonly used in offices and retail, public buildings, warehouses and logistics, light industrial units, showrooms and hospitality
It's important to note that foam extinguishers are not suitable for:
- Fires involving electricity (unless they have passed the 35kV dielectric test, in which case they are safe for accidental contact)
- Cooking oil fires (Class F), unless specifically stated on the extinguisher. Some foams are also rated for Class F fires.
- Reactive metals (Class D)
Compliance, Certification & Maintenance
When specifying or inspecting foam extinguishers, always check for:
- BS EN3 compliance
- CE Mark / UKCA Mark
- BSI Kitemark / LPCB Approval (where applicable)
To be kept in good working order, foam extinguishers should be:
- Serviced annually
- Replaced after 5 years or after use (unless they can be refilled)
- Decommissioned safely if they contain fluorinated compounds
Firechief’s PureSafe extinguishers are third-party approved and futureproofed to help you stay ahead of legislation like the UK’s 2025 PFOA ban and other upcoming changes to legislation.
Foam vs. Other Extinguishers: When to Choose Foam
| Fire Type | Foam | Powder | CO2 | Wet Chemical |
| Class A (solids) | ✅ | ✅ | ❌ | ✅ |
| Class B (liquids) | ✅ | ✅ | ✅ | ✅ |
| Class C (gases) | ❌ | ✅ | ❌ | ❌ |
| Electrical Fires | ⚠️ | ⚠️ | ✅ | ⚠️ |
| Class F (cooking oils) | ⚠️ | ❌ | ❌ | ✅ |
Key: ✅ Suitable for use | ❌ Not suitable for use | ⚠️ Check for markings on the extinguisher (dielectric test for Electrical fires, Class F mark for Class F foams)
Choose foam extinguishers when:
- You need a cleaner discharge than powder
- You want wide coverage for Class A/B risks
Final Word: Ready to Make the Switch?
With changing regulations and growing environmental expectations, now is the right time to upgrade your foam extinguishers, especially if they were installed before 2015.
Need help identifying compliant alternatives or planning a site-wide changeover? Speak to our expert team.
📞 Call +44 (0)330 999 0019
📧 Email sales@firechiefglobal.com
In addition to our foam fire extinguishers, the Firechief® range of fire safety products also includes extinguisher stands, suppression systems, signage and fire safety products for all types of fires. For information, call us on +44 (0)330 999 0019 or email sales@firechiefglobal.com.
To stay up-to-date with more product news and insights from across the fire safety industry, follow Firechief® Global on LinkedIn.
Disclaimer
The information contained within this blog is provided solely for general informational and educational purposes and is not intended as a substitute for professional advice. Before taking any actions based upon this information, we advise the reader to consult all relevant statutory or regulatory guidance and, where necessary, to consult a qualified fire or industry regulation professional. The use or reliance on any information contained herein is solely at the reader's risk.