How Often Should a Commercial Kitchen Extraction System Be Cleaned?

One of the most common questions we receive from commercial kitchen operators is: how often does my extraction system actually need to be cleaned?

The answer is not a single number. BESA TR19 — the industry standard for kitchen extraction cleaning — sets out a risk-based framework that determines cleaning frequency based on two key factors: the type of cooking carried out in the kitchen, and the hours of operation per week.

This guide explains the TR19 frequency requirements in plain English, with practical examples for the most common commercial kitchen types.

Understanding the TR19 Risk Categories

BESA TR19 divides commercial kitchens into four risk categories based on cooking type and operating hours:

Risk Category — Cooking Type — Operating Hours — Cleaning Frequency
--- — --- — --- — ---
Heavy — Deep-fat frying, wok cooking, chargrilling — 12–16 hours/day — Every 3 months
Moderate — Mixed cooking (grilling, frying, baking) — 6–12 hours/day — Every 6 months
Light — Low-fat cooking, steaming, baking only — Under 6 hours/day — Every 12 months
Very Light — Occasional use, light preparation only — Under 2 hours/day — Every 12–24 months

These are minimum frequencies. Your insurer may require more frequent cleaning, and some high-volume operations — such as dark kitchens or hospital kitchens — may require cleaning more often than the TR19 minimum.

Heavy-Use Kitchens: Every 3 Months

Heavy-use kitchens are those that carry out high-temperature, high-fat cooking for extended periods. The most common examples are:

Fish and chip shops — continuous deep-fat frying produces the highest grease deposits of any cooking method
Dark kitchens and ghost kitchens — typically operating 16–20 hours per day, seven days a week
Fast food restaurants — high-volume frying and grilling throughout the day
NHS hospital kitchens — continuous operation across multiple shifts
Busy gastropubs — extended service hours with a mix of frying and grilling

For these kitchens, TR19 cleaning every 3 months is the minimum requirement. Some very high-volume operations may require cleaning every 6 to 8 weeks.

Moderate-Use Kitchens: Every 6 Months

Moderate-use kitchens are those that carry out a mix of cooking methods for a standard service day. Common examples include:

Restaurants — typically serving lunch and dinner, with a mix of grilling, frying, and baking
Hotels — kitchen operating for breakfast, lunch, and dinner service
Pub kitchens — serving food during standard pub hours
Care homes — producing three meals per day for residents
School kitchens — operating for a single lunchtime service

For these kitchens, TR19 cleaning every 6 months is the standard requirement.

Light-Use Kitchens: Every 12 Months

Light-use kitchens are those that carry out low-fat cooking for limited hours. Common examples include:

Office canteens — producing light lunches for staff
Sandwich bars — limited cooking, primarily preparation
Cafés — light cooking, primarily hot drinks and snacks

For these kitchens, annual TR19 cleaning is typically sufficient — but this must be confirmed by a site survey, as the specific cooking methods used can change the risk category.

What Happens If You Don't Clean Often Enough?

Failing to clean your extraction system at the required frequency has three main consequences:

1. Insurance Policy Voidance

Most commercial kitchen insurance policies contain a condition requiring extraction cleaning at the frequency specified by BESA TR19. If a claim arises from a kitchen fire and the extraction system was not cleaned at the required frequency, the insurer may decline the claim — even if the fire was not directly caused by grease buildup in the extraction system.

2. Fire Safety Risk

Grease deposits in extraction systems are highly flammable. A flash fire in the cooking area can ignite grease deposits in the ductwork, spreading the fire rapidly through the building. UK Fire Statistics show that 61% of commercial kitchen fires are caused by grease buildup in extraction systems.

3. Enforcement Action

Environmental Health Officers and fire officers have the power to issue enforcement notices requiring extraction systems to be cleaned. Failure to comply can result in the kitchen being closed until the work is completed.

How to Determine the Right Frequency for Your Kitchen

The most reliable way to determine the correct cleaning frequency for your specific kitchen is to have a site survey carried out by a TR19-qualified specialist. During the survey, the technician will:

Assess the type of cooking carried out in the kitchen
Review the hours of operation
Inspect the current condition of the extraction system
Review your insurance policy requirements
Provide a written recommendation for the cleaning frequency

At BlueTick Extraction Hygiene, our CII-qualified founder reviews your insurance policy as part of every site survey — ensuring the cleaning frequency we recommend satisfies your insurer's exact conditions, not just the TR19 minimum.

Frequently Asked Questions

Can I reduce the cleaning frequency if I install a grease filter?

Grease filters reduce the amount of grease that enters the ductwork, but they do not eliminate it. TR19 cleaning frequencies apply to the entire extraction system — including the ductwork, risers, and fans — regardless of whether grease filters are fitted. Filters must also be cleaned or replaced regularly as part of the maintenance programme.

My kitchen has been closed for several months. Does the TR19 clock reset?

No. The TR19 cleaning frequency is based on operating hours, not calendar time. If your kitchen has been closed, the cleaning interval may be extended — but you should have the system inspected before reopening to confirm the current condition and establish the appropriate cleaning schedule going forward.

How do I know if my extraction system has been cleaned to TR19 standard?

A TR19-compliant clean must be documented with a compliance report that includes dated before-and-after photographs, grease deposit thickness measurements, and a signed technician declaration. If you do not have a current compliance report, you cannot demonstrate TR19 compliance to your insurer.

BlueTick Extraction Hygiene provides TR19 kitchen extraction cleaning across Peterborough, Cambridgeshire, Lincolnshire, and Northamptonshire. Call us on 07840 992 246 or request a free site survey.