How Many Fire Extinguishers Does a Business Need?

Key takeaway

For an ordinary Class A risk, government guidance uses one 13A-rated water-based extinguisher for about every 200 square metres, normally with at least two extinguishers on each floor. That is a starting point, not a shopping list. The fire risk assessment must also account for kitchens, electrical equipment, flammable liquids, workshops, travel distance, layout and the people expected to use the equipment.

Most ordinary UK workplaces use one 13A-rated water-based fire extinguisher for about every 200 square metres of floor space, with at least two extinguishers on each floor. That is the usual starting point for Class A risks such as paper, cardboard, wood and textiles.

The final number can be higher. Kitchens, electrical equipment, flammable liquids, machinery, workshops and awkward layouts can all require extra extinguishers of a different type. Your fire risk assessment decides what the premises needs.

The short answer

For a typical office, shop or similar low-risk workplace, use this as an initial check:

• Allow one 13A-rated water-based extinguisher for each 200 square metres of floor area.
• Normally provide at least two suitable extinguishers on each floor.
• Add the right extinguisher close to any specific risk, such as cooking oil, flammable liquid or electrical equipment.
• Position equipment where people can reach it without moving towards the fire.
• Confirm the final number, type and location through the fire risk assessment and a competent extinguisher survey.

The extinguisher count is based on fire rating, not simply the number of red cylinders. A compact water-additive unit may carry the same 13A rating as a larger traditional water extinguisher. Check the rating printed on the extinguisher rather than assuming its capacity tells you how much protection it provides.

How to calculate the basic Class A provision

Class A covers fires involving ordinary solid materials, including paper, cardboard, wood and many textiles. Government guidance for offices and shops says one water-based extinguisher for approximately every 200 square metres will normally be adequate, with a minimum of two extinguishers per floor.

A commonly used 13A extinguisher is rated against a standard test fire. The number does not mean it lasts for 13 minutes or covers 13 rooms. It is a performance rating.

Always round up, then check the layout. Four extinguishers grouped by one door do not give useful coverage across a long or divided warehouse.

Can a very small business have one extinguisher?

Sometimes. Some government premises guides allow one suitable extinguisher in a very small, self-contained premises under 90 square metres where the fire risk assessment supports it. This is an exception, not a blanket rule for every small office or shop.

The decision should consider the floor plan, escape route, work carried out, ignition sources and whether the single unit can deal with the likely fire types. A small takeaway kitchen and a small stationery office may have the same floor area but very different needs.

When does a business need extra extinguishers?

The Class A calculation only covers ordinary combustible materials. Add equipment where the assessment identifies another fire type or a localised hazard.

Dry powder can knock down several types of fire, but it can obscure vision, affect breathing and spread residue through equipment. It is not usually a good default choice inside offices, shops or other enclosed occupied spaces.

Where should fire extinguishers be positioned?

General-use extinguishers should normally sit on escape routes, near a room exit, floor exit or final exit. Someone using one should be able to keep a safe route behind them. Equipment for a specific hazard should be near that hazard, but not so close that a fire blocks access to it.

Government guidance says nobody should ideally have to travel more than 30 metres to reach an extinguisher. Walls, locked doors, racking and changes of level matter more than a straight-line measurement on a plan.

Extinguishers should be easy to see and mounted on a wall or suitable stand. Do not hide them behind stock, leave them loose on the floor or move them to make space for furniture. Signs may be needed where the position is not obvious.

Do fire extinguishers have to be serviced every year?

Portable extinguishers need a basic service by a competent person every year. BS 5306-3:2017 is the current British Standard for commissioning and maintenance. Your business should also carry out simple visual checks between services, usually monthly in normal conditions.

The routine check should confirm that each extinguisher is in its assigned place, unobstructed, apparently undamaged, still sealed and showing an acceptable pressure where a gauge is fitted. Record the check and deal with missing or damaged equipment promptly.

Some extinguishers also need an extended service or replacement at longer intervals. The timing depends on the extinguisher type and condition, so use the service record and competent engineer's advice rather than guessing from the cylinder colour.

Who is responsible for getting the number right?

In England and Wales, the responsible person must carry out and regularly review a fire risk assessment, put suitable fire precautions in place and maintain them. The responsible person may be the employer, owner, landlord, occupier, facilities manager or another person with control of the premises. Shared buildings can have more than one responsible person, and they must coordinate.

Scotland and Northern Ireland have separate fire safety legislation, but the practical approach remains risk based: assess the premises, provide suitable equipment and keep it maintained. If you manage sites in more than one UK nation, make sure the assessment refers to the law and guidance that apply at each address.

Common mistakes to avoid

• Counting cylinders without checking their fire ratings.
• Buying two identical extinguishers for every floor without looking at kitchens, plant rooms or electrical risks.
• Using CO2 units as part of the basic Class A calculation.
• Putting every extinguisher together at reception while leaving remote work areas uncovered.
• Choosing powder for a small occupied office because the label appears to cover more fire types.
• Missing annual services or failing to record routine visual checks.
• Keeping old extinguishers after the layout, equipment or use of the premises has changed.

What to ask for in an extinguisher survey

A useful survey should leave you with a schedule, not just a price. It should list each extinguisher's location, type, rating and service status, explain any additions or removals, and show how the recommendation follows the current fire risk assessment.

Ask the provider to identify obsolete, damaged or unsuitable equipment and explain any specialist risks that need input from the fire risk assessor. If the premises has changed since the assessment was written, update the assessment before treating the equipment schedule as final.

Fire extinguisher supply and servicing from FIDEC

FIDEC surveys, supplies, positions and services portable fire extinguishers for commercial premises. We can review an existing schedule, replace unsuitable units, label equipment and provide service records for single or multi-site businesses.

For fire extinguisher servicing in Manchester or wider planned work, book a free site survey through our contact page, call 0333 3662 007, or email info@fidecss.co.uk.

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