TR19 & standards
Two documents, two jobs. Asking for the wrong one can leave your grease extract uncleaned and your claim exposed.
The short answer
For kitchen extract you need TR19 Grease - the fire-risk specification. TR19 Air is a different BESA document covering the hygiene of general ventilation. A contractor who cleans and certifies to TR19 Air has not made your grease extract compliant, and a certificate that just says TR19 can hide that gap.
How one document became several
The confusion is historical. BESA's original guide, TR/19, covered all ventilation cleanliness in one book, with a single section - Section 7 - dealing with kitchen extract. In 2019 that section was withdrawn and republished on its own as TR19 Grease, a full specification aimed squarely at fire risk. Then in October 2023 BESA issued TR19 Air, the standalone document for the internal cleanliness and hygiene of general ventilation systems.
So today, saying 'TR19' without qualifying it is like saying 'the manual' when there are two on the shelf. For a commercial kitchen, the one that governs your greasy extract ductwork is TR19 Grease.
Why the mix-up is expensive
TR19 Air is about air quality and dust in supply and general extract ductwork - it even leans on BS EN 15780, a standard that explicitly does not cover kitchen extract. TR19 Grease is about combustible grease in the extract from your cookline, and carries its own thickness limits, verification and certification through BESA's BESCA scheme.
The commercial risk is simple: if you are handed a certificate that only covers air hygiene, or a generic 'TR19' clean that never measured grease, your fire risk assessment and your insurer may treat the extract as uncleaned. After a fire, that distinction is exactly what a loss adjuster will look for.
There is a slower cost too - paying for the wrong clean and standing still. An operator who books 'a TR19 clean' and receives an air-hygiene visit can assume the grease extract is dealt with, skip the specialist grease clean for another year, and let the ductwork drift past the 200-micron limit without ever knowing. The error usually only surfaces at a fire risk review, or a claim, by which point the exposure has been open for months. The renumbering history feeds the muddle: TR/19 once folded in the European ventilation-cleanliness standard BS EN 15780, which was never written for greasy kitchen extract in the first place. The safe habit is to name the specification you need when you commission work, then check the certificate names the same one back.
The limit
Knowing the two exist is not quite enough on its own - you have to check which one your paperwork names. A compliant kitchen-extract certificate should reference TR19 Grease specifically, record grease-thickness readings, and be registered through BESCA. If yours only says TR19 or points at air hygiene, treat the grease extract as unproven until someone measures it. The next guides cover what that proof should contain.
Questions
No. TR19 Grease is the standalone 2019 specification for fire risk from grease in kitchen extract. The older 'TR19' covered general ventilation cleanliness, now carried by TR19 Air (2023). Kitchen extract needs TR19 Grease.
Internal cleanliness and hygiene of general ventilation - supply and extract ductwork, air quality, dust. It draws on BS EN 15780, which specifically excludes kitchen grease extract.
Potentially. It is ambiguous. For kitchen extract you want it to name TR19 Grease and show grease-thickness readings. Ask the contractor to confirm in writing which specification the clean was certified to.
A contractor can clean both your grease extract and your general ventilation, but they are certified against different specifications with different tests. You should get clarity - and ideally documentation - for each.
For the kitchen, TR19 Grease - because it addresses fire risk. Insurers commonly ask for evidence of grease-extract cleaning to that specification before settling a fire claim.
Phoenix Duct Clean · by the numbers
Send us your last certificate. We'll tell you whether it actually covers your grease extract to TR19 Grease - and clean and certify the gap if it doesn't.