TR19 & standards
No jargon. What the fire-safety standard for your kitchen extract actually means, and what it asks you to do.
The short answer
TR19 Grease is the UK specification that says how clean the ductwork behind your canopy has to be, how often, and how you prove it - all to stop a grease fire spreading through the extract. If you run a commercial kitchen, it is the standard your insurer and fire risk assessment expect you to meet.
What it actually is
TR19 Grease is published by BESA - the Building Engineering Services Association, the trade body (founded in 1904, once the HVCA) that has set duct-cleaning standards since the late 1990s. In 2019 the kitchen-extract part was pulled out of the older TR/19 guide and published on its own as a full specification: Fire Risk Management of Grease Accumulation within Kitchen Extraction Systems.
The word specification matters. The old guidance told you what good looked like; the specification sets measurable pass marks a contractor has to hit and record. It is not an Act of Parliament, so nobody is going to prosecute you for breaching TR19 Grease by name - but it is the yardstick everyone else uses to judge whether your extract was cleaned properly, which is a different kind of teeth entirely.
The one number to remember
You do not need to be an engineer to hold on to the single figure at the heart of it. Grease inside the ductwork must be controlled so the mean average stays under 200 microns - roughly half the thickness of a business card - between scheduled cleans. Let it build past that and the system is judged a fire risk; a patch at 500 microns or more needs cleaning straight away.
Everything else - how often you clean, what a good clean looks like, what paperwork you get - flows from keeping that number down across the whole run, not just the bit you can see when you look up under the canopy.
It helps to know where the standard came from, because the lineage explains its authority. BESA's duct-cleaning guidance began as TR/17 in 1998 and grew into TR/19, with kitchen extract as a single section until the fire risk earned it a document of its own. Insurers have leaned on that line of guidance for decades. That is why a specification written by a trade body, with no criminal penalty attached, still carries real weight - it is the reference the whole industry, and the people who decide whether to pay out after a fire, have quietly agreed to use.
The limit
Meeting TR19 Grease is what a fire risk assessor and an insurer want to see, and a valid certificate is often what makes a fire claim payable rather than contested. What it will not do is run itself: the standard only protects you if the clean is genuinely done to it, by a qualified technician, across the whole system, and documented. A certificate for a canopy wipe is worth very little. The rest of this cluster takes each piece - the numbers, the proof, the scope - one at a time.
Questions
Not by name. It is a BESA specification, not legislation. But the Regulatory Reform (Fire Safety) Order 2005 makes you responsible for managing fire risk, and TR19 Grease is the recognised way to show you are doing that for your extract - which is why insurers and fire risk assessors ask for it.
Any premises with a commercial kitchen extract system - restaurants, pubs, hotels, schools, hospitals, takeaways and canteens. The duty falls on the Responsible Person for the building, usually the operator or the landlord depending on the lease.
It is the maximum mean grease thickness allowed inside the ductwork between cleans - about half a business card. Above it the system is treated as a fire risk; 500 microns or more in a spot needs immediate attention.
No. You need to know the target (a 200-micron mean), that the whole system counts, and that you should get a proper post-clean report and certificate. A competent contractor handles the technical side.
With a post-clean report - before and after photos, grease-thickness readings and a certificate registered through BESA's BESCA scheme. Keep it with your fire safety records.
Phoenix Duct Clean · by the numbers
We survey the whole system, tell you where you stand against TR19 Grease, and clean and certify to it. No jargon, no scare tactics.