Fire extinguisher colours & types: the UK guide
Grab the wrong extinguisher and you can make a fire worse — water on a fryer, or on live electrics, is how a manageable incident becomes a dangerous one. The colours are a code. Once you know it, the right choice is obvious in a second.
Why they're all red now
Before 1997, UK extinguishers were colour-coded across the whole body — a black CO2, a blue powder, and so on. Today, under BS EN 3, every extinguisher body is red, with a coloured band or panel (roughly 3–10% of the surface) showing the type. The single red colour makes them easy to spot in smoke; the band tells you what's inside.
The five colours you'll actually meet
- Red band — Water. For ordinary combustibles: wood, paper, textiles, most rubbish. Never use on cooking oil or anywhere near live electrical equipment.
- Cream band — Foam (AFFF). Good on combustibles and on flammable liquids like petrol or paint thinners, where it forms a blanket that smothers the fire.
- Black band — CO2. The go-to for electrical risks and flammable liquids. It leaves no residue, so it's kind to computers and machinery — but it doesn't cool, so a fire can reignite.
- Blue band — Dry Powder. Versatile (solids, liquids, gases, and safe near electrics), which is why it's common outdoors and on vehicles. Indoors it's a last resort: the cloud wrecks visibility and is hard to breathe, so current guidance discourages it in occupied buildings unless the risk assessment calls for it.
- Yellow band — Wet Chemical. The kitchen specialist. It reacts with burning cooking oil to form a soapy, sealing layer (saponification) that cools and smothers the fire. The right — and often only — sensible choice for deep-fat fryers.
A sixth type, water mist (white band), is increasingly used in mixed-risk settings because the fine mist is effective across several fire types with minimal mess.
Fire classes: match the extinguisher to the fuel
UK fire classes come from BS EN 2. The extinguisher has to suit the class of fuel that's actually present:
- Class A — solids (wood, paper, fabric)
- Class B — flammable liquids (petrol, oils, solvents)
- Class C — flammable gases
- Class D — metals (specialist powder only)
- Class F — cooking oils and fats
There is no "Class E" in the UK. Electrical fires aren't given a letter — instead, an extinguisher safe to use near live electrics carries an electrical spark symbol. CO2 and dry powder are the usual choices; water and foam are not.
Getting the mix right
Most premises need more than one type. A typical office runs water or foam for general (Class A) risks plus CO2 for electrical equipment. A commercial kitchen adds wet chemical near the cooking line. The specifics — how many, what rating, and where — are set out in BS 5306-8, and driven by your fire risk assessment under Article 9 of the Fire Safety Order.
Wall-mount extinguishers on brackets (never left on the floor), on escape routes and near the hazards they cover, with signage above them in larger buildings. As a rule of thumb, no one should travel more than about 30 m to reach a Class A extinguisher, and a Class B unit sits within around 10 m of its risk. Have them serviced annually by a competent person.
The one habit worth drilling
In a real incident there's no time to read the label carefully. The colour band and the pictogram should trigger the right choice automatically — which only happens if you've made that choice enough times before. That recognition, under a little time pressure, is exactly what turns "I think it's the yellow one" into muscle memory.
Practise this in the game
The Extinguisher Match drill throws real scenarios at you and asks for the right unit — against the clock.
Play Hazard Hunt →This guide is for learning and applies to England & Wales. Always work from the current standards and your own fire risk assessment; Scotland and Northern Ireland have equivalent regimes.