Compliance
How Often Should Commercial Kitchen Extract Systems Be Cleaned?
Understanding TR19 Grease cleaning frequencies, insurance requirements, and how to keep your kitchen extract system compliant and fire-safe.
Bright Hygiene • 4 min read
Why Cleaning Frequency Matters
Commercial kitchen extract systems accumulate grease over time. Left unchecked, this build-up becomes a serious fire hazard, reduces airflow efficiency, and puts your business at risk of failing insurance and hygiene inspections.
The frequency of cleaning depends on several factors: the daily hours of operation, the volume and type of cooking, and the specific requirements of your insurer or local authority.
What TR19 Grease Says About Cleaning Frequency
TR19 Grease, published by the Building Engineering Services Association (BESA), is the UK's recognised industry standard for fire risk management of grease accumulation within kitchen extraction systems. Since 2019 it has been a standalone specification, separate from TR19 Air which covers general ventilation hygiene.
TR19 Grease bases cleaning frequency on the daily hours of kitchen operation:
Heavy-use kitchens (12–16 hours per day): every 3 months. Moderate-use kitchens (6–12 hours per day): every 6 months. Light-use kitchens (2–6 hours per day): every 12 months.
These are baseline intervals. Your extract cleaning provider should also assess your system using a Deposit Thickness Test (DTT) or Wet Film Thickness Test (WFTT). Under TR19 Grease, grease deposits exceeding 200 microns require the entire system to be cleaned, and after cleaning, deposits must measure less than 50 microns across all tested surfaces.
Insurance Requirements
Many commercial property insurance policies require evidence of regular extract cleaning to maintain cover. If a fire starts in a poorly maintained extract system and you can't demonstrate a cleaning history, your claim could be rejected.
Some insurers, such as Aviva, specifically require that a TR19-compliant service provider carries out the work. Always check your policy wording. Most insurers expect cleaning to be documented with before-and-after photographic reports and a formal certificate of hygiene. At Bright, we provide TR19-compliant reports with every clean for exactly this reason.
Signs Your System Needs Cleaning Now
Don't wait for the next scheduled clean if you notice any of these warning signs: visible grease build-up on canopy surfaces or filters, reduced airflow or extraction performance, unpleasant odours persisting in the kitchen, grease dripping from ductwork or fan units, or filters that are saturated and no longer effective.
If you're unsure about the condition of your system, a free survey from a specialist provider like Bright can assess the current state and recommend the right cleaning schedule going forward.
Getting It Right
The key is not to treat extract cleaning as a one-size-fits-all task. A kitchen operating 16 hours a day will need far more frequent attention than one running for just a few hours.
Work with your cleaning provider to establish a schedule based on your actual hours of operation and measured grease accumulation, and make sure you receive the documentation you need for insurance and inspections.
