Free guide for facilities teams
Kitchen Extract Compliance: A TR19 Grease Guide for FM Teams and Landlords
Grease in kitchen extract systems is one of the most common causes of fire spreading through commercial buildings. This guide explains what TR19 Grease expects, how to tell whether your system is being maintained properly and what records to keep.
1. Why kitchen extract needs its own regime
Cooking releases grease that condenses on canopies, filters, ductwork and fans. Unlike dry dust, it is combustible and can carry fire along the extract route. BESA publishes separate guidance for these systems, TR19® Grease, with its own measurement method and cleaning frequencies.
2. Minimum cleaning frequency
| Kitchen use | Hours per day | Minimum frequency |
|---|---|---|
| Heavy | 12–16 | Every 3 months |
| Moderate | 6–12 | Every 6 months |
| Light | 2–6 | Every 12 months |
These are minimums. Cooking type, system condition, your fire risk assessment and your insurer may require more frequent cleaning.
3. How grease is measured
Wet Film Thickness Testing (WFTT) uses a comb gauge to measure the depth of wet or soft grease deposits, in microns, at identified locations along the extract route.
| Reading | What it means |
|---|---|
| Mean of 200 µm or more | Grease must be controlled so the mean does not exceed 200 µm between scheduled cleans — cleaning is due |
| 500 µm or more at any location | Immediate spot cleaning is required at that location |
| After cleaning | Deposits should be well below the 200 µm threshold, confirmed by post-clean WFTT at the same locations |
4. Who is responsible?
- The person who controls the premises (the 'responsible person' under the Regulatory Reform (Fire Safety) Order 2005) must assess and manage fire risk, which includes kitchen extract.
- Lease and management agreements decide whether that is the landlord, managing agent or occupier for a particular system — check them.
- Caterers and FM contractors often arrange the cleaning, but the records should reach whoever holds fire-safety responsibility.
5. Records to keep
- Dated post-clean report covering the whole route
- WFTT readings before and after cleaning
- Photographs linked to test locations
- Record of inaccessible sections
- Cleaning frequency matched to hours of use
- Access-panel schedule and recommendations
6. Checking your contractor's report
- Does it cover canopy to discharge, not just the canopy?
- Are readings taken at the same locations before and after?
- Are inaccessible sections recorded?
- Is the mean below 200 µm and no location at 500 µm or more?
- Is the next clean date set by hours of use?
7. Common problems we find
- Only the canopy and filters cleaned, not the ductwork
- Too few access panels to clean or inspect the full route
- Cleaning frequency set by habit rather than hours of use
- Reports with no readings or photographs
Kitchen extract assessment
Green Air Monitoring independently inspects the full extract route, measures grease with WFTT and verifies cleaning without selling cleaning services.
This guide is general information and does not replace BESA TR19® Grease, your fire risk assessment or your insurer's requirements. TR19® is a registered trademark of the Building Engineering Services Association.