Quick reference · Portable fire extinguishers: servicing, siting and colours

BS 5306 (extinguishers): quick reference

How portable fire extinguishers are chosen, positioned, colour coded, checked and serviced.

How many fire extinguishers a building needs, where they go, what the colours mean, and how they are checked and serviced.

BS 5306-3:2017, BS 5306-8:2023, BS 5306-10:2019. Part 3 covers servicing (2017, current and under review), part 8 covers selection and positioning (2023) and part 10 covers colour coding (2019, which replaced BS 7863).

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How often are extinguishers serviced?

A basic service at least once a year by a competent person. An extended service every 5 years for water, foam, wet chemical and powder extinguishers. CO2 extinguishers are overhauled every 10 years with a hydraulic pressure test. The Responsible Person checks them by eye every month.

Every year a competent person services them. Every five years there is a fuller service. CO2 ones get a pressure test every ten years. Each month, someone in the building checks them by eye.

Monthly check, yearly basic service, five-yearly extended service, and a ten-year overhaul for CO2.

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How much can the weight vary?

The mass check tolerance is plus or minus 5% of the charge.

The weight of the contents can be up to 5% out either way.

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How high do extinguishers go on the wall?

The handle at no more than 1 m from the floor, or 1.5 m for extinguishers with a total mass under 4 kg.

Hang them so the handle is no higher than 1 m. Light ones, under 4 kg, can go up to 1.5 m.

Hang them on the wall or a stand, never on the floor. The handle is at 1.5 m for light units and 1.0 m for heavier ones.

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How many extinguishers does a storey need?

A storey of 50 m² or less needs at least one extinguisher, with a total Class A rating of at least 26A. A larger storey needs at least two, totalling at least 26A up to 400 m². Above 400 m² the total is 0.065 times the floor area in m², about 13A for every 200 m².

Small floors need one, and enough rating to reach 26A. Bigger floors need at least two. Above 400 m², add about one 13A extinguisher for every 200 m².

Total Class A rating needed for a storey over 50 m². Divide by the rating of the extinguisher you use, and never fewer than two.

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How far should anyone have to go to reach an extinguisher?

No more than 30 m to a Class A extinguisher, and 10 m for Class B and Class F risks. Take 5 m off for each door someone has to open.

Nobody should walk more than 30 m to a normal extinguisher. For flammable liquids or cooking, 10 m. Each door you have to open takes 5 m off.

Nobody should walk more than 30 m to a Class A extinguisher, or 10 m for flammable liquids and cooking. Each door takes 5 m off.

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What do the colour bands mean?

The body is red. The band shows the contents: water has a red body with no band, foam is cream, ABC powder is blue, CO2 is black, wet chemical is canary yellow and Class D powder is signal violet. BS 5306-10:2019 replaced BS 7863, and older extinguishers made to it remain acceptable.

All extinguishers are red. A coloured stripe tells you what is inside: no stripe is water, cream is foam, blue is powder, black is CO2, yellow is wet chemical, violet is metal-fire powder.

The body is always red. The band shows what is inside.

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Which extinguishers can be used on live electrical equipment?

Only extinguishers whose contents do not conduct electricity: CO2, powder or clean agent. Water-based extinguishers conduct electricity and should not be used. Electrical equipment is not a fire class in the UK. Isolate live equipment before discharge where you can.

Use CO2 or powder near live electrics. Never use water or foam. If you can switch the equipment off, do that first.

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What are the fire classes?

Class A is solids such as wood and paper. Class B is flammable liquids. Class C is flammable gases. Class D is metals. Class F is cooking oils and fats.

A is ordinary materials, B is liquids, C is gases, D is metals and F is cooking oil.

What each type is for. Never use water or foam on live electrical equipment.

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How should extinguishers be mounted?

On the wall with the carry handle at 1.5 m for smaller units and 1.0 m for heavier ones, or on a stand or plinth. Not on the floor.

Hang them on the wall at a sensible height, or put them on a stand. Never leave them on the floor.

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Where should extinguishers be placed?

On escape routes near exits, in the same place on each storey, grouped as fire points. Each point should be signed so a missing unit is noticed and replaced. This is from the 2012 edition.

Put them near exits on escape routes, in the same spot on each floor, with a sign at each point.

From guidance on the 2012 edition. Check the 2023 wording.

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What deals with a deep fat fryer?

Wet chemical. A fire blanket is limited to small fryers, up to about 300 mm across or 3 litres. Foam, powder and CO2 are ineffective on cooking oil.

Use a wet chemical extinguisher on a big fryer. A fire blanket is only for small pans. Foam, powder and CO2 do not work on cooking oil.

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How much cover is needed for flammable liquids?

It depends on the exposed liquid surface area and how far apart the containers are. Containers under 2 m apart count as one group.

The bigger the area of liquid, the more cover you need. Containers less than 2 m apart count together.

From guidance on the 2012 edition. Check the standard.

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Is CO2 safe in a small room?

It can be dangerous. Guidance says 4% CO2 in the air causes symptoms and 8% can kill, so CO2 should not be used in small rooms.

CO2 pushes out the air you breathe. Do not use it in a small room.

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What goes on the service record and label?

The serial number, date, engineer, type of visit, defects found and next due date. The label shows the next due date, and the tamper seal is renewed at the annual service.

Record the serial number, date, who did it, what was done, faults and when it is next due. Put the next due date on the label and fit a new tamper seal.

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Other guides: BS 5839-1, BS 5839-6, BS 5266-1 and BS EN 1838, BS EN 50131-1 and PD 6662, BS 8418, BS EN 62676-4, BS EN 60839-11-1, BS 7273-4, BS 7671 (for alarm and CCTV work). Not sure what a word means? Explain this text or see the glossary.

For guidance only. Always check against the current edition of the standard and the manufacturer's data.

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