How often must a fire extinguisher be serviced?

How often must a fire extinguisher be serviced?

BS 5306-3 defines four kinds of service, and knowing which one you are being sold is the difference between a fair invoice and a poor one: the basic service, the extended service, a recharge after use, and an overhaul. They are not interchangeable, and the interval attached to each depends on what is inside the extinguisher.

The monthly visual check is yours

Nothing on that list requires training, which is exactly why it is your job rather than a contractor's. And it matters more than it sounds, because the failures it catches are the common ones. An extinguisher does not usually fail because its internals degraded quietly; it fails because somebody moved it to prop a door, stacked boxes in front of it, walked off with it, or set it off and quietly put it back on the bracket.

An annual visit cannot see any of that. It sees the state of the building on one day out of three hundred and sixty-five.

The annual basic service

The weight check is the one worth understanding, because it is what a visual inspection cannot do. An extinguisher is stamped with its charged weight. Putting it on scales tells you whether the contents are still all there, which a gauge showing green does not, since a slow leak of extinguishant can leave propellant pressure looking perfectly normal.

The label matters too, and not for bureaucratic reasons. It is the fastest way for anybody, you, an inspector, an insurer, to see when the extinguisher was last touched and by whom, without opening a file.

The extended service: five years, or ten for CO2

The reason the two diverge is physical rather than administrative. A water, foam or powder extinguisher is a container of something that can settle, cake, corrode or degrade where you cannot see it, so periodically it has to be emptied and inspected from the inside. A CO2 extinguisher is a high-pressure gas cylinder, and the question that matters about a pressure vessel is whether the vessel itself is still sound, which is answered by a pressure test, on the longer cycle used for cylinders.

Here is where money gets wasted. An extended service is not a replacement, and a five-year-old extinguisher is not expired. It is due a deeper service, after which it goes back on the wall. Quoting a new unit instead is quicker for a supplier and occasionally justified, a corroded or obsolete extinguisher genuinely should be replaced, but it should be a stated recommendation with a reason attached, not the default that arrives in year five.

The half everybody forgets: the right one, in the right place

The failures we find on survey are almost always siting failures rather than servicing failures:

• Water next to electrical intake. The wrong medium entirely, and dangerous in use rather than merely useless.
• No wet chemical in a commercial kitchen. Cooking oil fires are Class F and neither water nor a standard foam addresses them.
• Everything by the front door. Tidy, and it leaves the far end of a floor outside the 30 metre travel distance.
• Extinguishers on the floor. Off the bracket means moved, obstructed, or gone by the time it is needed, and unsigned.
• A CO2 removed after a false alarm and never returned. The gap is invisible on paper because the unit is still on the asset list.

Every one of those buildings had a current service label on every extinguisher. The paperwork was in order. The provision was wrong. That is why an fire risk assessment looks at extinguisher provision as a question about the building rather than a question about the extinguishers.

Who is allowed to service an extinguisher

The duty to appoint a competent person sits with you, not with the contractor, so it is worth asking what somebody is assessed against before appointing them rather than afterwards. Ask what standard they work to, what happens to a unit that fails, and whether an extended service is carried out or quietly converted into a sale.

Extinguishers are the part of fire safety that looks the simplest and drifts the fastest, because they are physical objects in a building full of people who move things. The monthly walk is the cheapest control you have over that, and it is the one most often skipped.