Guide · TR19 Grease · UK-Wide
Cleaning frequency is set by how hard your kitchen cooks, not the calendar. Heavy frying points to every three months, moderate use to six, light use to twelve - here is how to find the right interval for your cookline.
The short answer
Under TR19 Grease - the standard insurers and fire risk assessors work to - cleaning frequency is set by how hard the kitchen runs, not by the calendar. As a working rule:
Those three bands are starting points, not a verdict. The right interval for your cookline comes from measuring the grease load on the actual system, which is what a survey does. What follows is what moves the number up or down - and why an off-the-shelf once a year is the wrong answer for most kitchens.
What sets it
Two kitchens of identical size can sit on completely different schedules. The variables that decide yours are:
This is why a credible cleaner asks about your menu and your hours before quoting an interval - and why a flat annual contract sold without that conversation is a warning sign.
How it's measured
TR19 Grease ties cleaning to grease accumulation, not to a fixed date. On a survey the grease deposit is checked at points along the system - from the canopy, through the ductwork, to the extractor fan - and where it is building fastest, the interval shortens. That measurement is the difference between a schedule that matches your real fire risk and one that is essentially a guess.
The standard works to clear numbers. Grease is measured in microns through the system, and the mean reading should stay below 200 microns; once the average passes that, the full system is due a clean, and any single reading above 500 microns needs dealing with there and then. After a clean, a Deposit Thickness Test or Wet Film Thickness Test should confirm the system is back below 50 microns - around half the width of a human hair. The hours-of-use bands at the top of this page are the fallback the standard offers when no measured readings exist yet; once your system has been surveyed, those readings set your interval.
Every clean should finish with a certificate that records what was done, carries before-and-after photographs, and sets a next-due date based on what the system actually looked like. That certificate is the document your fire risk assessor and your insurer will ask to see - so the interval written on it carries real weight.
Why it matters
For a heavy-use cookline, an annual clean leaves grease building for months past the point it should have been cleared. That gap matters on three fronts at once:
Cleaning to the correct interval costs a fraction of any one of those going wrong. The point of getting the frequency right is not tidiness - it is keeping a known fire risk inside safe limits, with the paperwork to prove it.
Questions
There is no single fixed interval written into law, but you have duties under fire safety legislation to manage the risk, and most insurers require cleaning at the TR19 Grease risk-based frequency. In practice the effect is the same - you need to clean at the interval your grease load dictates, and hold the certificate to prove it.
It is measured on a survey against TR19 Grease - the grease deposit is checked through the system and the interval is set from what is found, then recorded on your certificate with a next-due date.
Filters and the canopy load fastest and can be wiped or cleaned more often in-house, but the ductwork and extractor fan must be cleaned on the risk-based interval. A canopy-only clean is not TR19 compliance and will not satisfy an insurer.
That is exactly what a survey is for. We measure the grease load on your actual system rather than guessing from the kitchen type, so the interval matches your real risk.
Yes. We work overnight, early mornings or on closing days, with no extra charge for out-of-hours work, so the clean does not cost you a service.
Yes. Under TR19 Grease the technician carrying out and signing off the work should hold the BESA Grease Hygiene Technician qualification. Using an unqualified contractor can leave you with a clean that does not satisfy your insurer - the certificate is only worth as much as the competence behind it.
Phoenix Duct Clean · by the numbers
Tell us your cooking type and your hours. We will survey the grease load and set the correct TR19 interval. No-obligation quote, UK-wide.