Types against fire classes.
| Extinguisher | Colour band | Fire classes | Never use on |
|---|---|---|---|
| Water / water mist | Red / white band | A (solids: wood, paper, textiles) | Live electrical, oils, fats |
| Foam (AFFF) | Cream | A, B (flammable liquids) | Cooking oils; caution near live electrical |
| CO₂ | Black | B, electrical equipment | Class A deep-seated fires; confined spaces caution |
| Dry powder | Blue | A, B, C (gases), electrical | Indoor use discouraged — visibility, inhalation, cleanup; not for Class F |
| Wet chemical | Yellow | F (cooking oils and fats), A | —; the mandatory choice for commercial kitchens |
| Specialist lithium-ion agents | Per product | Li-ion battery fires (emerging provision) | Specified by risk assessment where battery risk is concentrated |
How many, and where.
- Class A baseline (BS 5306-8): a minimum combined rating of 26A per floor, typically met by two 13A extinguishers (e.g. 9-litre water or 6-litre foam) per storey on anything but the smallest floors; small premises under ~100m² may justify a single 13A unit.
- Travel distance: no more than 30m from any point to a Class A extinguisher (20m for B risks, 10m from a Class F risk to the wet chemical unit).
- Siting: on escape routes, at final exits and stair landings, adjacent to specific risks — fixed to brackets or stands, handle around 1m from floor for larger units, signed where not conspicuous.
- Pairing: electrical risk areas pair CO₂ with the Class A cover; kitchens pair wet chemical with a fire blanket at the cooking line.
Commissioning, servicing, records.
- Commissioning on site by a competent person when installed.
- Monthly visual checks in-house: in place, unobstructed, pressure gauge in the green, pin and tamper seal intact, no damage — logged.
- Annual basic service by a competent technician to BS 5306-3, labelled and certificated.
- Extended service: discharge test and refill at five years (water, foam, powder); CO₂ overhaul at ten years.
Service labels and certificates join the alarm and emergency lighting records as the documentation trio every assessor, auditing officer and insurer requests.
"Where necessary... the responsible person must ensure that the premises are, to the extent that it is appropriate, equipped with appropriate fire-fighting equipment and with fire detectors and alarms."Article 13(1), Regulatory Reform (Fire Safety) Order 2005
Training and the first-aid firefighting decision
Extinguishers are first-aid equipment for nascent fires and for fighting a path to escape — nothing more. Article 21 training should cover which extinguisher for which risk and, above all, when not to fight: fire larger than a waste bin, smoke at ceiling level, or any doubt means evacuate. Some premises legitimately adopt an evacuate-only policy for staff; the assessment records that decision and provision is scaled accordingly — the equipment must still be present and maintained for escape-path protection.
Key fact: The commonest extinguisher findings are administrative: missing annual service, units on the floor behind stock, wrong type at the risk (water beside the fryer). Every one is visible in thirty seconds at audit — and every one is closed for the price of a service contract and a bracket.