Kitchen extract cleaning: grease, fire risk, TR19 and how often ducts need cleaning

What is kitchen extract cleaning, and how is it different from a deep clean?

Kitchen extract cleaning removes grease from inside the extraction system: canopy, plenum, filters, ductwork and fan. A kitchen deep clean covers the surfaces and equipment you can see and reach. They're often booked together, but they're different jobs.

Cooking produces grease-laden vapour. The canopy catches it, filters strip out some of the grease, and a fan pulls the rest of the air through ductwork to the outside. Filters never catch everything. Grease settles inside the canopy, in the space behind the filters (the plenum), along the duct and on the fan. Most ductwork is hidden above ceilings or in risers, so nobody sees the build-up.

A commercial kitchen extract clean usually involves:

• isolating the fan and protecting the cooking equipment below
• degreasing the filters, canopy and plenum, including drip trays
• getting into the ductwork through access panels and removing the grease
• cleaning the fan housing and impeller
• measuring and photographing the system before and after, and writing a report

Daily and weekly cleaning looks after food hygiene. Extract cleaning mainly manages fire risk. Most kitchens need both, on different schedules.

Why is grease in kitchen ducts a fire risk?

Grease is combustible. A flare-up on a range or fryer can be drawn into the canopy and ignite deposits in the plenum and duct. A fire inside ductwork can spread through the building where it's hard to see and hard to reach.

BESA says fires involving commercial kitchen extract systems, as either the source or a contributory factor, have focused the attention of insurers, property owners and landlords on making sure these systems are correctly cleaned and maintained. The reasons are practical:

• The fuel is already there. Grease can coat the duct along its whole length.
• The air flow feeds it. The fan pulls heat and flame along the duct.
• It's out of sight. Ducts often pass through ceiling voids, other floors or neighbouring premises.

A canopy can look clean from the kitchen floor while the duct a metre above it is heavily coated.

What should kitchen staff clean, and what needs a specialist?

Kitchen staff normally clean the parts they can safely reach and remove: grease filters, canopy surfaces and drip trays, on a written schedule. The plenum, ductwork and fan need a specialist with the access, equipment and training to clean them safely and record the result.

Splitting the job clearly avoids the most common gap: everyone assumes someone else is cleaning the duct.

The FSA's Safer Food, Better Business "Your cleaning schedule" safe method asks you to write down how you clean each item, the chemicals and equipment you use and how often. It also says some specialist equipment has dismantling and cleaning instructions that should be followed. Put filters and canopy surfaces on that schedule, then add a line for the specialist duct clean with the last and next due dates.

What is TR19 Grease, and do I have to follow it?

TR19 Grease is BESA's specification for fire risk management of grease accumulation within kitchen extraction systems. It isn't legislation, but BESA says it's endorsed by British insurers and the building engineering services community, and it's the benchmark extract cleaning is usually measured against.

TR19 is published by BESA, the Building Engineering Services Association, in two parts. TR19 Air covers the hygiene of general ventilation systems. TR19 Grease ("Fire Risk Management of Grease Accumulation within Kitchen Extraction Systems") covers kitchen extracts. BESA says it was first produced as a stand-alone specification in 2019 and can be used for new build, upgrade and maintenance.

BESA describes TR19 as setting a clear, measurable benchmark for cleanliness. Its Vent Hygiene Register page says TR19 Grease and TR19 Air are recognised by the RISCAuthority, British Standards and London Fire Brigade.

Is TR19 the law?

No. The legal duty is to assess and manage fire risk and maintain your fire precautions (see below). TR19 Grease is a recognised way of doing the extract part properly and showing you've done it, which is why insurers, landlords and fire risk assessors refer to it. Insurance policies may require extract cleaning to a recognised standard, so check your policy wording.

TR19 Grease is a paid document, so we haven't quoted it. It sets out how often systems should be cleaned and how cleanliness is measured and recorded. If you need the exact figures, for a tender or to check a report, buy the current edition from BESA or ask your contractor to show you the relevant section.

Who is legally responsible for kitchen extract fire safety?

In England and Wales it's the 'responsible person' under the Regulatory Reform (Fire Safety) Order 2005: usually the employer, or whoever controls the premises. They must assess fire risk, put fire safety measures in place and keep them maintained. Scotland and Northern Ireland have their own laws.

Article 3 of the Fire Safety Order says the responsible person for a workplace is the employer, if the workplace is to any extent under their control. Otherwise it's whoever controls the premises in connection with a business or undertaking, or the owner. GOV.UK adds that owners, landlords, occupiers and people such as facilities managers and managing agents can be responsible too, and that where there's more than one responsible person, they must work together.

GOV.UK says the responsible person must:

• carry out a fire risk assessment, keep a written record and review it regularly
• tell staff about the risks identified
• put in place, and maintain, appropriate fire safety measures
• plan for an emergency and provide fire safety training

Article 17 requires fire safety facilities and equipment to be subject to a suitable system of maintenance and kept in good repair. Fire and rescue authorities inspect premises and can issue fire safety notices, and GOV.UK warns you could be fined or go to prison for not following fire safety regulations.

The law doesn't mention kitchen ducts by name. But a greasy extract is an obvious fire hazard, so your fire risk assessment should identify it and say how it's controlled: interval, who cleans it, and how it's recorded. If yours is silent on the extract, raise it with your assessor.

Shared buildings and leased kitchens

Ducts often run through parts of a building the kitchen operator doesn't control. Check your lease, then agree in writing who arranges cleaning for each part and who provides access to risers, ceiling voids and the roof.

Scotland and Northern Ireland

The Fire Safety Order covers England and Wales. In Scotland, Part 3 of the Fire (Scotland) Act 2005 applies: section 53, for example, requires employers to assess fire risks to employees and take the necessary fire safety measures. Northern Ireland has its own legislation, including the Fire Safety Regulations (Northern Ireland) 2010. The approach is similar, but the duties and wording differ.

How often should a kitchen extract be cleaned?

It depends on how much and what you cook. The cleaning intervals are set out in TR19 Grease, and grease measurements at each clean show whether your interval is right. A kitchen cooking long hours every day needs cleaning far more often than one doing a few light meals.

The law doesn't set one interval. Yours should come from your fire risk assessment, guided by TR19 Grease, your insurer's conditions and what each clean finds. Things that shorten it:

• Hours of cooking. Breakfast to late evening, seven days a week, puts far more grease into the system than lunchtimes only.
• Type of cooking. Frying, grilling and wok cooking produce much more grease than steaming or baking.
• Filters. Missing, damaged or rarely cleaned filters let more grease into the duct.
• Previous findings. Heavy deposits at the last clean mean the interval is too long.

Why do access panels matter, and what if ductwork can't be reached?

You can't clean or inspect what you can't reach. Ductwork needs access panels so its full length can be cleaned. If parts are inaccessible, the report should say so, because those sections haven't been cleaned.

Older kitchens and ducts boxed in during a fit-out often have long stretches with no way in. A contractor can only clean as far as their tools reach. Everything beyond is left as it was, but you still get photos of a clean canopy.

• Ask for a survey on a system with no drawing or cleaning history, to trace the route and say where panels are needed.
• Fit missing panels using a competent ductwork installer. Take advice before cutting into ducts or fire-resisting walls and floors they pass through.
• Keep panels reachable, not blocked by new ceilings or shelving, and mark them on a drawing kept with your fire records.

What should a kitchen extract cleaning report contain?

A good report shows what was cleaned and what wasn't, with before-and-after photos and grease measurements along the system, any defects, and when the next clean is due. It's your evidence for your fire risk assessment, landlord and insurer.

The report is the first thing an insurer, landlord or fire safety inspector will ask for. Check it before you file it:

File reports with your fire risk assessment and diarise the next clean as soon as the report arrives.

Can the kitchen keep trading while the extract is cleaned?

Not during the work itself: the fan has to be off and the cooking area protected. Most kitchens book it overnight or on a closed day, so no service is lost.

Agree these points before the night:

• Access: keys, alarm codes, roof access, and landlord permission in shared buildings.
• Isolation: who switches off and restarts the fan and any gas interlock linked to it, so the kitchen can start safely in the morning.
• Food areas: remove or cover food and equipment. Clean and disinfect food-contact surfaces again before use, following your food safety procedures.
• Chemicals and waste: how grease waste and wash water are contained and removed.
• Sign-off: walk the kitchen with the team leader before they leave, or first thing.

If you're also booking a kitchen deep clean, do it after the extract work, so the dirtiest job is done first.

What should I ask a kitchen extract cleaning specialist?

Ask whether the quote covers the full system or only the canopy, what standard they work to, what training their operatives hold, how they measure grease, and to see a sample report.

The biggest risk is paying for a partial clean and thinking it was a full one. A canopy-only clean is useful, but it leaves the grease in the duct and fan.

We don't publish prices: there's no official source for extract cleaning rates, and every system differs. Price is driven by duct length and route, existing access, how heavy the grease is, out-of-hours working and roof access. Our office cleaning costs page explains how cleaning quotes are built from time, people, equipment and margin.

The same rules apply to school kitchens, staff canteens and care home kitchens, which are often run by a caterer in a building managed by someone else. Make sure the fire risk assessment and the catering and cleaning contracts agree on who arranges the duct clean. For the routine side, see school cleaning, office cleaning and GP surgery cleaning.

Related guides

Kitchen extract cleaning: frequently asked questions

Sources

We checked the facts on this page against these sources on 12 November 2026:

• BESA: TR19 Air and Grease competence and compliance toolkit
• BESA Vent Hygiene Register: why specify VHR contractors
• GOV.UK: Fire safety in the workplace
• GOV.UK: Fire risk assessments
• Regulatory Reform (Fire Safety) Order 2005, article 17 (maintenance)
• Fire (Scotland) Act 2005, section 53
• Food Standards Agency: Safer food, better business for caterers

This guide is general information for UK organisations, not legal, health and safety, infection control or employment advice. Business Cleaning Hub is an independent guide. We don't provide cleaning services ourselves. If you ask us to, we'll put you in touch with one commercial cleaning company from our partners that covers your area.

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