Guide
TR19 Grease: what it is, what it is not, and what to ask for
Updated
TR19 Grease comes up in every kitchen extract conversation and is routinely described as a legal requirement. It is not. Here is the accurate version, and why it still matters to you.
What TR19 and TR19 Grease actually are
TR19 is the Building Engineering Services Association's guide to good practice on the internal cleanliness of ventilation systems. TR19 Grease is the companion guidance covering grease-laden kitchen extract systems specifically: how they should be accessed, cleaned and verified. Both are industry guidance documents published by BESA. Neither is legislation, neither is enforced by a regulator in its own right, and no contractor can be prosecuted for departing from it.
Say this clearly, because the industry often does not: TR19 Grease is guidance, not law. A contractor telling you that cleaning to TR19 Grease is a legal requirement is describing the industry benchmark as though it were statute. The benchmark is worth following. The framing is wrong, and it should make you read the rest of their claims more carefully.
Where the legal duty comes from
For most non-domestic premises in England and Wales, the fire safety duty sits in the Regulatory Reform (Fire Safety) Order 2005. Article 3 defines the responsible person, usually the employer or the person with control of the premises. Article 9 requires that person to make a suitable and sufficient assessment of the risks to which relevant persons are exposed, so that the general fire precautions needed can be identified. Article 17 requires that fire safety equipment and facilities are maintained in an efficient state, in efficient working order and in good repair.
Grease accumulating inside kitchen extract ductwork is a recognised fire risk: it is fuel, sitting in a path that runs through the building, above a source of ignition. That means it is something a suitable and sufficient fire risk assessment has to consider, and something the responsible person has to manage. The law does not name TR19 Grease. What TR19 Grease gives you is a recognised method for doing what the law requires, and a way of evidencing that you did it.
The insurance angle, which is often the real driver
Insurers commonly ask for evidence of kitchen extract cleaning to TR19 Grease, and policy wordings for restaurants and hotels frequently make cleaning at a stated frequency a condition of cover. That is a contractual requirement rather than a statutory one, but the consequence of failing it, a declined claim after a fire, is severe enough that it drives most buying decisions in this market. Check your own policy wording rather than relying on what a contractor tells you it says.
What to ask a contractor for
- A pre-clean survey identifying the system layout, existing access points and where new ones are needed.
- A written scope naming canopy, filters, ductwork, fan and discharge point separately, each marked in or out.
- Post-clean verification with before and after photographs at recorded locations, and measured deposit readings rather than a visual opinion.
- An explicit list of anything that could not be cleaned, with the reason, because that is what a fire risk assessor will ask about.
- A recommended next clean date with the reasoning behind it.
- Confirmation of which edition of the guidance they work to, since the documents are revised.
TR19 Grease uses measured deposit thickness rather than a visual judgement to decide whether a system needs cleaning and whether a clean has succeeded. We are not printing a threshold figure here, because it depends on the current edition and we would rather you got it from the document or your contractor than from us. Ask which figure they are measuring against, and ask to see the readings on your own report.