What Is BESA TR19, and Why It Matters for Your Commercial Kitchen
TR19 is BESA's specification for keeping ventilation systems clean inside. The part written for commercial kitchens is TR19 Grease. It is guidance, not law, but it is how you show that the grease in your extraction has been dealt with.
Reviewed 26 October 2026
What Is BESA TR19?
TR19 is published by BESA, the Building Engineering Services Association, the trade body for building services contractors. It is the specification for keeping ventilation systems clean inside, and it now comes in two parts.
TR19 Grease is the one for commercial kitchens. Its full title is TR19® Grease Specification for Fire Risk Management of Grease Accumulation within Kitchen Extraction Systems, and BESA first released it as a stand-alone specification in 2019. It is about fire: grease that collects in the canopy, ductwork and fan.
TR19 Air (TR19® Air Specification: The Specification for Internal Cleanliness and Hygiene Management of Ventilation Systems) covers air handling units and general supply and extract ductwork. It is about air hygiene, has its own training, and is a different job. When a kitchen operator, broker or fire risk assessor says "TR19", they mean TR19 Grease.
TR19 is not legislation and BESA is not a regulator. The legal duty is to manage fire risk under the Regulatory Reform (Fire Safety) Order 2005, and a clean to TR19 Grease is the recognised way to evidence it. The laws that apply to kitchen extraction are set out separately.
What TR19 Grease Covers
The specification follows the job from survey to paperwork. A clean that skips any of these steps can still end in a certificate, which is why it is worth knowing what they are.
- 1. Risk assessment and inspectionThe whole system is surveyed from canopy to discharge: what is there, what condition it is in, where grease collects and which sections can be reached.
- 2. AccessDuctwork can only be cleaned where it can be reached, so the specification deals with access panels: where they are needed and what they must be.
- 3. MeasurementGrease deposit thickness is measured at recorded points before cleaning and again afterwards, so the result is a reading rather than an opinion.
- 4. Cleaning and verificationThe system is cleaned and the result checked against the specification, with photographs taken so a third party can see what was found and what was left.
- 5. Cleaning frequencyThe interval is set by how many hours a day the kitchen cooks: every 3 months for 12 to 16 hours, every 6 months for 6 to 12 hours, every 12 months for 2 to 6 hours.
- 6. RecordsA post-clean report and certificate that say which parts of the system were cleaned, which were not, and when the next clean is due.
BESA TR19: Common Questions
What is TR19?
TR19 is the specification published by BESA, the Building Engineering Services Association, for cleaning the inside of ventilation systems, in two parts: TR19 Grease for commercial kitchen extraction (fire risk) and TR19 Air for general ventilation (air hygiene). It is industry guidance, not law, and when a kitchen operator, insurer or fire risk assessor says "TR19" they almost always mean TR19 Grease.
What is the difference between TR19 Grease and TR19 Air?
TR19 Grease is the Specification for Fire Risk Management of Grease Accumulation within Kitchen Extraction Systems. BESA first released it as a stand-alone specification in 2019, taking kitchen extract systems out of the general TR19 document. TR19 Air is the specification for the internal cleanliness and hygiene management of ventilation systems such as air handling units and supply ductwork. They are separate documents with separate training. BlueTick works to TR19 Grease only.
What does a TR19 Grease clean cover?
The whole extraction system, not just the canopy: the canopy and grease filters, the plenum behind the filters, the full run of ductwork, the extract fan and the discharge point. Grease depth is measured at recorded points before and after, the clean is photographed, and the certificate says which sections were cleaned and which could not be reached.
Is TR19 a legal requirement?
No. TR19 is BESA guidance, not legislation. The legal duty is to manage fire risk under the Regulatory Reform (Fire Safety) Order 2005, and cleaning to TR19 is the recognised way to show the grease in your extraction has been dealt with.
Who is BESA, and is it a regulator?
BESA is the trade association for building engineering services contractors in the UK. It writes technical specifications and runs training through the BESA Academy. It is not a regulator and does not enforce TR19; the fire and rescue authority enforces fire safety law, and your insurer sets the terms of your policy.
How does BESA TR19 relate to insurance?
Insurers do not publish TR19; BESA does. But where a commercial kitchen policy has an extraction cleaning condition, TR19 is the specification contractors clean to, so the certificate is what you show to evidence the condition was met. BESA itself says insurance providers increasingly expect ventilation systems to be maintained to a recognised standard. Read your own policy schedule for the exact wording and interval.
What is the Vent Hygiene Register?
A register run with BESA that lists approved member contractors, who can notify completed cleans through it. Being on it is one way a contractor shows they work to TR19. BlueTick is not on the register and does not say it is; the work is done by an operator holding the BESA Academy Grease Hygiene Operative and Grease Hygiene Technician qualifications.
Where can I get the BESA TR19 standard?
From BESA, which sells TR19 Grease and TR19 Air through its publications site; both are free to BESA members. They are technical specifications written for contractors, and a copy posted on another site may not be the current edition. Most kitchen operators do not need their own copy: they need a certificate and report from a contractor who works to the current edition.
What is wet film thickness testing?
A way of measuring how much grease is on a duct surface: a gauge is pressed into the deposit at a recorded point and the depth read off in microns. TR19 Grease uses deposit measurements, taken before and after cleaning, to decide whether a system needs cleaning and to show that it was cleaned. A single reading shows one point only, which is why the report should say where each one was taken.
How Grease Buildup Becomes a Fire Hazard
Every time a commercial kitchen operates, cooking vapours rise into the extraction canopy and travel through the ductwork. As these vapours cool, grease condenses and adheres to the internal surfaces of the duct system. Over time, this creates a thick, highly flammable layer throughout the entire extraction network.
A single spark, a flash of flame from the cooking surface, or even the sustained heat of normal cooking operations can ignite this grease. Once alight, a duct fire can travel rapidly through the entire extraction system — often bypassing suppression systems designed only for the cooking area — and spread into the building structure.
Because the ductwork is hidden, grease can build up for months without anyone noticing, and a fire that starts inside the duct can reach the building structure before it is seen. The cost is not only the damage: a kitchen can be closed for weeks while the system is replaced.
Regular TR19-compliant cleaning removes grease deposits before they reach dangerous levels — and provides documented evidence that you have done so.
The Legal Framework Behind TR19
TR19 is not legislation. These four laws are what apply to a commercial kitchen extract system. None of them names TR19; cleaning to TR19 Grease is the recognised way to show the grease risk they cover has been dealt with.
Regulatory Reform (Fire Safety) Order 2005
The responsible person (usually the operator or employer) must carry out a suitable and sufficient fire risk assessment (article 9) and take general fire precautions (article 8).
Grease in the canopy, ductwork and fan is fuel in a channel that runs through the building. The assessment should identify it and say how it is controlled: in practice, how often the system is cleaned and how you know it was done.
Enforced by: Local fire and rescue authority
Health and Safety at Work etc. Act 1974
Employers, and anyone in control of premises used as a workplace, must take reasonable measures, so far as reasonably practicable, to keep premises, plant and equipment safe and without risks to health.
The extraction system is plant. Leaving it to fill with grease is a foreseeable risk to staff and others.
Enforced by: Local authority environmental health (most catering) or HSE
Workplace (Health, Safety and Welfare) Regulations 1992
Regulation 6 requires effective and suitable ventilation in every enclosed workplace; regulation 5 requires workplace equipment and systems to be maintained in efficient working order and good repair.
The kitchen canopy and extract are how a catering kitchen meets regulation 6, so they have to be kept working.
Enforced by: Local authority environmental health or HSE
Food hygiene rules: Regulation (EC) 852/2004, Annex II (retained in UK law)
Food premises are to be kept clean and maintained in good repair, and ventilation systems are to be constructed so that filters and other parts needing cleaning are readily accessible.
Grease filters and ductwork have to be reachable for cleaning, which is why access panels matter.
Enforced by: Local authority environmental health (food hygiene inspections)
After a fire, the questions are whether your fire risk assessment covered the extraction system and whether the precautions in it were carried out. A dated TR19 certificate and post-clean report are how you show that. The full answer, with sources, is on TR19 regulations: is TR19 a legal requirement? This page is general information, not legal advice.
How Often Does Your Kitchen Need a TR19 Clean?
TR19 Grease sets the cleaning interval by how many hours a day the kitchen cooks. These are the minimum intervals — your insurer or fire risk assessor may specify more frequent cleaning.
| Usage Level | Operating Hours | Typical Example | Minimum Frequency |
|---|---|---|---|
| Heavy Use | 12–16 hours/day | A busy takeaway or pub kitchen | Every 3 months |
| Moderate Use | 6–12 hours/day | A café open through the day | Every 6 months |
| Light Use | 2–6 hours/day | A school, office or church-hall kitchen | Every 12 months |
Source: BESA TR19® Grease. Hours of cooking a day set the interval; the examples are typical, not rules. Where your insurance policy sets its own interval, that is the one to follow.
- High-volume restaurants
- Takeaways & fast food
- Hotel kitchens
- Stadium & event catering
- Busy pub kitchens
- Café bistros
- Care home kitchens
- School canteens
- Contract catering
- Office staff canteens
- Light-use cafés
- Village halls
- Community centres
- Occasional event kitchens
TR19 and Your Commercial Insurance Policy
A commercial kitchen policy can include a condition that the extraction system is cleaned to TR19, sometimes with its own interval. Where yours does, it is a term of your contract rather than law: read the wording, note the interval it sets, and keep the evidence that each clean was done.
The evidence is the TR19 certificate and the post-clean report behind it: which parts were cleaned, grease readings before and after, dated photographs, and any section that could not be reached. Your broker or insurer can ask for it at renewal or after a claim, so keep every one, not just the latest.
BlueTick Extraction Hygiene was founded by a CII (Chartered Insurance Institute) qualified professional who also works alongside Focus Insurance Services, an FCA-regulated commercial insurance brokerage. Our reports are laid out so a broker or underwriter can find the dates, scope and readings quickly.
What Happens If the Extraction Is Not Cleaned?
Skipping a TR19 clean is not itself an offence. The risks come from the fire-safety law, from your policy terms and from the grease itself.
Legal Consequences
- A fire risk assessment that ignores the extraction falls short of the Fire Safety Order 2005
- Enforcement notices from the fire and rescue authority
- Prohibition notices where the risk is serious
- Prosecution for serious breaches of the Order
- Questions from environmental health about dirty canopies and filters
Financial Consequences
- No evidence that your policy's cleaning condition was met
- Harder conversations with your insurer at renewal
- Fire damage to the building, equipment and stock
- Business interruption losses
- Emergency clean-up and system replacement costs
Operational Consequences
- Forced closure during emergency remediation
- Equipment failures from contamination
- Grease dripping from the canopy into the cooking area
- Reputational damage to the business
- A lower food hygiene rating if canopy and filters are dirty
What a TR19-Compliant Service Report Must Contain
Not all cleaning certificates are equal. A post-clean report to TR19 Grease should carry the evidence a broker, fire risk assessor or fire officer can ask for. Check yours has these.
The BlueTick Difference
Our reports are reviewed through the lens of an insurance professional — ensuring every data point an underwriter needs is present and correctly documented.