Foam fire extinguishers are a popular choice across UK workplaces, and for good reason. They’re quick, effective and widely approved for multiple fire risks. But like all extinguishers, they’re not a “one-size-fits-all” solution.
If you're responsible for fire safety, knowing where foam extinguishers should (and shouldn’t) be used is key to protecting people, premises and peace of mind.
How Foam Extinguishers Work
Foam extinguishers are designed to tackle:
- Class A fires – solid combustibles like wood, paper and textiles
- Class B fires – flammable liquids like petrol, diesel and solvents
- Class F fires (only some models) – cooking oils and fats
The foam forms a smothering film that cools the fire and prevents re-ignition by sealing the flammable surface.
But they’re only safe for accidental use on live electrical equipment, which makes placement critical.
Where Foam Extinguishers Should Be Used
Foam extinguishers are ideal for areas where solid and flammable liquid fires are a real risk, especially when there’s no live electrical hazard nearby.
Here are some examples:
Petrol Stations & Fuel Storage
Why: Petrol, diesel, and other fuels are a Class B fire risk. Foam is effective at tackling fires involving these volatile liquids and preventing reignition.
Tip: Always place the foam units away from pumps but within reach of the forecourt.
Workshops & Maintenance Bays
Why: Foam works well on oily rags, solvent spills, and flammable adhesives, plus common combustibles like cardboard packaging.
Tip: Use foam in tool storage zones or beside workbenches, not near circuit boards or charging bays.
Office Storage Areas
Why: Piles of paperwork, cardboard stock, or old records can catch fire easily. Foam handles Class A fires efficiently.
Tip: Use foam in print rooms, archive spaces, or under-stairs cupboards (if no electrical panels are present).
Factories & Manufacturing Sites
Why: Where paints, thinners or chemicals are stored, foam helps to cool and contain fire spread.
Tip: Always check the chemical compatibility before use.
Where Foam Extinguishers Should NOT Be Used
There are several high-risk scenarios where foam is unsuitable and can make the situation worse.
Electrical Cabinets, Server Rooms or Office IT Areas
W"hy not: Although most foam extinguishers have been tested for accidental use on electricals, foam can conduct electricity. Spraying onto live electrical equipment could result in electric shock or damage to critical systems.
Instead use: If it's standard electronic equipment, use CO2 extinguishers. If it's a lithium-ion battery fire, use specialist lithium-ion extinguishers.
Reception Areas with Plug Sockets or Charging Stations
Why not: Even a small live socket can turn a foam discharge into a shock hazard.
Tip: If unsure, choose dual protection by having a foam and a CO2 extinguisher side by side.
Flammable Metals or Lithium-ion Batteries
Why not: Foam is ineffective against reactive metals (Class D) and lithium-ion cells, which burn differently and may reignite.
Instead use: For lithium-ion battery fires, use Firechief® Lith-Ex extinguishers. For Class D metal fires, use specialist metal powder extinguishers.
Construction Sites with Unfinished Electrics
Why not: Foam spray in damp or partially wired areas may cause unintentional current paths.
Better suited: Powder or CO2 extinguishers for focused electrical hazards.
Placement Best Practice: A Quick Checklist
Before installing or using foam extinguishers, ask:
Are Class A or B risks present (solids or liquids)?
Is there live electrical equipment nearby (the less, the better)?
Can the extinguisher be reached quickly?
Are staff trained to recognise extinguisher types?
If the answer to these questions is satisfactory, foam is likely the right fit.
Changes to legislation around foam fire extinguishers
From 4th July 2025, UK regulations have tightened around AFFF foam extinguishers by banning those containing PFOA, a type of PFAS chemical. While not all PFAS chemicals are prohibited yet, this legislation marks a clear shift towards more sustainable fire safety practices and stricter environmental controls. We’ve long been preparing for this transition, and our PFAS-Free PureSafe extinguishers offer a compliant, future-proof alternative, helping you stay ahead of the curve while keeping people and the planet safer.
In addition to our Lithium-ion battery fire extinguishers and welding blankets, 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.