Fire Extinguisher Types UK: Colour Codes, Fire Classes and the Law

Fire extinguishers are the piece of fire safety equipment most people walk past every day and never think about — until the day they are needed. In the UK, providing them is not optional. The Regulatory Reform (Fire Safety) Order 2005 (RRO) places a legal duty on the responsible person for almost every non-domestic premises to ensure the building is equipped with *appropriate* fire-fighting equipment, that it stays in working order, and that staff know how to use it.

The word *appropriate* matters: a water extinguisher can make a cooking-oil fire violently worse, a CO2 unit cannot put out a deep-seated paper fire, and powder discharged indoors can blind and choke people trying to escape. The wrong type is a life-safety issue, and fire and rescue authorities treat it as one.

This guide covers the UK fire classes, the everyday extinguisher types and colour codes, which extinguisher is safe on which fire, how many you need and where to put them, the servicing schedule that keeps them legal, and the 2025 ban on older foam units.

Is a fire extinguisher a legal requirement?

Under article 13(1) of the RRO, the responsible person must ensure that premises are, "to the extent that it is appropriate," equipped with fire-fighting equipment and with fire detectors and alarms, and that any non-automatic fire-fighting equipment is easily accessible, simple to use and indicated by signs.

The word *appropriate* is deliberate: the RRO sets no fixed number or type. Instead the fire risk assessment (article 9) identifies your premises' risks, and the extinguishers you provide must suit those specific risks. BS 5306-8:2023 — *Selection and positioning of portable fire extinguishers* — is the technical benchmark assessors, insurers and enforcing authorities use to judge adequacy.

The RRO applies to workplaces, shops, restaurants, pubs, care homes, schools, places of worship, common areas of flats and HMOs, and virtually all other non-domestic premises in England and Wales. It does not apply to single private dwellings, though landlords carry duties under the RRO and, in some cases, separate regulations.

Get this wrong and the consequences are serious. Fire and rescue authorities can serve an enforcement notice (article 30) or a prohibition notice closing all or part of the premises (article 31). Under article 32, failing the fire safety duties where anyone is put at risk of death or serious injury is a criminal offence — on conviction on indictment, an unlimited fine, up to two years' imprisonment, or both.

The fire classes in the UK: A, B, C, D, F — and now L

Extinguishers are matched to fires by *class*, defined in BS EN 2:1992 — the British and European standard for classification of fires:

• Class A — solid combustible materials: wood, paper, cardboard, textiles, most plastics
• Class B — flammable liquids: petrol, diesel, oils, solvents, paints
• Class C — flammable gases: propane, butane, methane, LPG
• Class D — combustible metals: magnesium, sodium, aluminium swarf
• Class F — cooking oils and fats: deep-fat fryers, chip pans
• Electrical — not a class of its own: electricity is an ignition source, not a fuel. Fires involving live electrical equipment are dealt with using an extinguisher rated as safe for use near live equipment

There is no official "Class E" in UK standards — avoid the term. In January 2026, BS ISO 3941:2026 added a new Class L for fires involving lithium-ion cells and battery packs (no metallic lithium present): e-bikes, e-scooters, power tools, forklifts, EVs and battery storage. Class L fires can enter thermal runaway, reignite long after appearing extinguished, and release toxic gases. The classification does not change extinguisher ratings under BS EN 3 — but if lithium-ion batteries are charged or stored on your premises, your fire risk assessment should say so and your emergency plan should reflect it.

Fire extinguisher types and colour codes

Since BS EN 3 came into force in the late 1990s, every extinguisher sold in the UK has a signal-red body with a coloured band or panel above the label telling you what is inside. The colour code is set out in BS 5306-10:2019. Pre-1997 units may be coloured all over — a fully blue powder unit, a fully cream foam unit — and should be replaced when they reach the end of their service life.

| Extinguisher | Band colour | Fights | Never use on | |---|---|---|---| | Water | Red (no band) | Class A solids | Live electrical, cooking oils, flammable liquids (can spread the fire) | | Foam | Cream | Class A and B | Cooking oils (Class F), live electrical unless dielectrically tested | | Dry powder (ABC) | Blue | Class A, B, C and live electrical | Cooking oils (reignition risk); not recommended indoors by default | | Carbon dioxide (CO2) | Black | Class B and live electrical | Deep-seated Class A (reignition), cooking oils | | Wet chemical | Yellow | Class F cooking oils (and usually Class A) | Flammable liquids and gases, live electrical | | Water mist | White | Class A, and B/F on model-dependent ratings | Check the rating on the individual unit |

Specialist dry powders for Class D metal fires sit outside this everyday set and carry a violet band (L2 powder for lithium metal, M28 powder for magnesium and similar).

Which fire extinguisher for which fire?

Water (red) cools the burning material and is the workhorse for Class A risks — offices, shops, schools, paper, wood and textile storage. Never use it on live electrical equipment (the jet conducts), flammable liquids (it spreads the fire) or cooking oils (violent eruption).

Foam (cream) is the most versatile everyday choice: it extinguishes Class A solids and Class B liquids by blanketing the fire to starve it of oxygen, and it is the standard for mixed-risk premises — offices, retail units, workshops. Standard foam is not safe on live electrical equipment, though some units are dielectrically tested for use at 1 metre — check the label. And check foam units against the 2025 PFOA ban below.

Dry powder (blue) knocks down Class A, B and C fires and is tested for live electrical use up to around 1,000 V at 1 metre — the default for garages, forecourts, plant, vehicles and outdoor risks. Indoors it is a poor first choice: discharge destroys visibility, the fine powder is a respiratory irritant, and the residue is expensive to clean. It must not be used on cooking-oil fires — it cannot stop reignition.

Carbon dioxide (black) is the no-residue option for Class B fires and live electrical equipment — server rooms, switchgear, laboratories. It has almost no cooling effect and cannot penetrate deep-seated Class A fires, which can reignite once the gas disperses. The horn becomes dangerously cold in use, and CO2 displaces oxygen: never discharge it in an unventilated confined space.

Wet chemical (yellow) is the only everyday extinguisher safe on Class F cooking-oil fires. Its fine mist of potassium acetate reacts with hot oil through saponification, forming a soapy blanket that smothers the fire and stops reignition. It is effectively mandatory wherever there is a deep-fat fryer — restaurants, takeaways, pubs, hotel kitchens, staff canteens — sited within roughly 10 metres of the cooking risk. A fire blanket (BS EN 1869) is a sensible addition for small pan fires and clothing alight.

Water mist (white) is the newer multi-class option — Class A and, model-dependent, B and F — with very little water damage. It is increasingly specified for heritage buildings, archives and other sensitive occupancies.

The golden rules: never use water or foam on live electrical equipment, never use water on oil or liquid fires, never use a unit on a fire class it is not rated for — and when in doubt, get out, close the door and call the fire service.

How many fire extinguishers do I need?

There is no statute that says "one per 200 square metres" — your fire risk assessment determines the exact provision. But BS 5306-8 gives the benchmark assessors and enforcers work to:

• One 13A-rated Class A extinguisher per 200 m² of ordinary floor area (a 9-litre water or 6-litre foam unit typically carries 13A)
• A practical minimum of two 13A units per floor (26A combined) for most premises, so one failed or used unit never leaves a floor unprotected — very small premises of well under 100 m² may justify a single unit where the risk assessment supports it
• Maximum 30 metres' travel distance to a Class A extinguisher from any point in the premises — measured along the route people actually walk, not as the crow flies
• Class F provision close to the hazard: wet chemical units within roughly 10 metres of the fryer
• Class B and electrical risks covered specifically: CO2 units near switchgear and server rooms, foam or powder near liquid storage
• At least one extinguisher per floor in multi-storey buildings, positioned consistently so people always know where to look

Siting matters as much as numbers: on escape routes, near exits and adjacent to hazards; visible; signed with the fire-fighting equipment sign; and mounted so the carrying handle is around 1 metre above the floor. A unit hidden behind stock, used as a doorstop or mounted out of reach breaches article 13's requirement that equipment be "easily accessible."

Fire extinguisher servicing: the BS 5306-3 schedule

Providing extinguishers is only half the duty. Article 17 requires all fire-fighting equipment to be "subject to a suitable system of maintenance" and kept in efficient working order. The maintenance standard is BS 5306-3:2017:

• Commissioning on installation — every new unit must be commissioned when first installed. Units bought online and hung on a wall without commissioning are a recurring finding in audits
• Monthly visual checks — by the responsible person or a nominated employee: correct location, unobstructed and visible, pressure gauge in the green zone, tamper seals intact, no obvious damage. Record the check in a logbook
• Annual basic service — every 12 months (± 1 month) by a competent person (typically BAFE SP101 certificated): weigh, check pressure, inspect hose and nozzle, check for corrosion, replace seals, date the service label
• Extended service at 5 years — water, foam and powder units require a discharge test and internal examination after five years, then five-yearly thereafter
• CO2 overhaul at 10 years — CO2 units require a hydraulic pressure test and overhaul at ten years
• Replace, don't refill from the shelf — any unit that has been used, even partially, or fails inspection must be taken out of service and replaced or professionally recharged

Servicing records matter. Missing records are treated by insurers and enforcing authorities as equivalent to missing extinguishers. Keep the logbook, the service labels and the certificates together with your fire risk assessment.

Foam extinguishers: the 2025 PFOA ban

If you hold foam (AFFF) extinguishers, act on this: from 4 July 2025, the use, servicing, testing and refilling of fire-fighting foams containing PFOA (a persistent PFAS "forever chemical") is banned in the UK, and many older AFFF units are caught. Units above the limit must be taken out of service and disposed of as hazardous waste; the industry has moved to fluorine-free (F3) foam and water-mist alternatives. Current fluorotelomer-based (C6) foams remain lawful but face staged restrictions from October 2026. Ask your service engineer to confirm compliance; the HSE's REACH restrictions pages and FIA guidance cover the detail.

Staff training: owning an extinguisher is not the same as using one

Article 21 requires the responsible person to train employees at induction, when risks change, and at regular intervals. Using an extinguisher is a skill, not an instinct: a 13A water unit discharges in around 20–30 seconds, and the "PASS" sequence (Pull, Aim, Squeeze, Sweep) is quickly forgotten without practice. Staff fire safety training is a legal duty in its own right, and HawkSwift's certified fire safety courses include practical extinguisher familiarisation.

The most important message keeps people alive: extinguishers are for early-stage fires, from a safe position, with an escape route behind you. If the fire is growing, smoke is building or you are not confident — close the door, raise the alarm and leave.

Getting the extinguisher provision right starts with the risk assessment

The extinguisher question cannot be answered from floor area alone — a nail salon, a care home kitchen and an aerosol warehouse need completely different provision, which is why the law routes the decision through a suitable and sufficient fire risk assessment. If yours is out of date, was done from a template without a site visit, or never covered the equipment question, 7 questions worth asking any FRA provider will help you judge it. HawkSwift's qualified assessors carry out site-based assessments across England and Wales, our store stocks compliant extinguishers, signage and fire blankets, and you can book an assessment online.

FAQ

Do fire extinguishers need to be checked every month? Yes. BS 5306-3 requires a monthly visual inspection by the responsible person or a nominated employee — location, unobstructed access, pressure gauge in the green zone, intact tamper seals and no visible damage — with the checks recorded in a logbook.

How often do fire extinguishers need servicing? An annual basic service by a competent person (typically BAFE SP101 certificated) is required every 12 months, plus an extended service with discharge test every 5 years for water, foam and powder units, and a 10-year hydraulic overhaul for CO2.

Is it illegal to not have a fire extinguisher in the UK? In non-domestic premises, yes where the fire risk assessment shows one is needed. The RRO 2005 requires the responsible person to provide appropriate fire-fighting equipment; failing to do so where people are put at risk is a criminal offence punishable by an unlimited fine and up to two years' imprisonment.

Can I use a water extinguisher on an electrical fire? No. Water conducts electricity and creates a serious shock risk on live equipment. Use a CO2 or dry powder extinguisher rated for electrical use, or isolate the power first if it is safe to do so.

What extinguisher do I need for a deep fat fryer? A wet chemical (yellow band) extinguisher, sited within roughly 10 metres of the fryer. Never use water — it causes violent eruption — and dry powder cannot prevent reignition.

Which fire extinguisher is best for a car? A 1 kg or 2 kg dry powder unit is the usual recommendation — it covers Class A, B and C fires. Keep it secured so it cannot become a projectile in a collision.

Are foam fire extinguishers banned? Not as a type. What is banned since 4 July 2025 is foam containing PFOA (an older PFAS chemistry). Foam units using compliant fluorine-free or permitted chemistries remain lawful, but any older AFFF unit should be checked by a service engineer.