How to prevent commercial kitchen extractor fires

Authored by QBE  Senior Risk Manager John Driscoll

Fire is one of the biggest risks for any business that operates kitchen facilities.

Most commercial kitchens will build-up deposits of fat, oil and grease inside the extract ventilation ductwork, which if not regularly cleaned, can contribute to fire risk.

For a fire to start and spread it needs three things – heat, fuel, and oxygen. All three are present in a commercial kitchen ventilation system. Heat and flames from the cooking process can mix with oxygen in the extractor and if it latches onto flammable fatty residues inside the ductwork acting as a fuel source, the results can be disastrous.

Which businesses are at risk?

The food and drink sector is obviously a prime candidate for fire risk - cafes, pubs, restaurants, fish and chips shops, and fast food outlets.

Busy kitchens are also found in a huge range of commercial premises, including hospitals, factories, schools, prisons, care homes, hotels, leisure centres and motorway service stations. 

In many buildings, the kitchen is often on the ground floor. When fire breaks out it can spread quite rapidly throughout the ductwork, the rest of the building, and even to other buildings, resulting in loss of business, costly and lengthy repairs, or worse – loss of life.

A well-known example is often cited from 1997 of a fire starting in a fast food restaurant at London’s Heathrow Airport. As the fire spread, Terminals 1, 2 and 3 had to be closed, thousands of passengers were evacuated, and 300 flights were cancelled. The investigation traced the source of the fire back to grease deposits in the ductwork above the restaurant.

How can the fire risk be reduced?

One of the most important factors in reducing the fire risk is cleanliness.

Of course, for an area involved in preparing food we expect a kitchen to be clean, but this also applies to the parts not immediately visible – inside the ventilation system.

As far as possible all parts of the extract need to be cleaned, which may require the use of access hatches, or in the extreme, dismantling of ductwork. Any newly installed system should be designed with access hatches built in, but many older installations will need access hatches retrofitting. In some cases where access hatches can’t be installed, the use of long reach cameras and cleaning equipment will be required to get to the hidden spots.

A useful guide to read is ‘RC68: Recommendations for fire safety in catering establishments’ published by RISCAuthority, in association with the Fire Protection Association. The recommendations apply to the installation, management, operation and maintenance of cooking appliances and related equipment in commercial catering kitchens, including the use of fire suppression over the cooking range and within the extract duct.

The standard that applies to how a commercial kitchen duct and extract system should be cleaned is ‘TR19: Internal cleanliness of ventilation systems’, which outlines a 'defined, measurable level of cleanliness'. TR19 is published by The Building Engineering Services Association (BESA), and is the standard widely used by insurers and compliance bodies.

TR19 contains tables and guidance on how often each type of ventilation ductwork should be cleaned, according to its use. All fat, oil and grease residue must be removed at each clean, including from the least accessible areas. Such deep cleaning is best carried out by a competent specialist cleaning contractor, who will usually provide evidence of the cleaning process with before and after photographs.

Cleaning regularity will depend on the perceived level of grease production and the average number of hours that the kitchen is being used for.

High level of grease production

  • Light use (up to 6 hours a day): cleaned every six months
  • Moderate use (6-12 hours a day): cleaned every three months
  • Heavy use (12-16 hours a day): cleaned every three months
  • Very heavy use (over 16 hours a day): cleaned every two months

Medium level of grease production

  • Light use (up to 6 hours a day): cleaned every twelve months
  • Moderate use (6-12 hours a day): cleaned every six months
  • Heavy use (12-16 hours a day): cleaned every four months
  • Very heavy use (over 16 hours a day): cleaned every three months

Low level of grease production

  • Light use (up to 6 hours a day): cleaned every twelve months
  • Moderate use (6-12 hours a day): cleaned every twelve months
  • Heavy use (12-16 hours a day): cleaned every six months
  • Very heavy use (over 16 hours a day): cleaned every six months

Maintaining a regular cleaning schedule as defined by TR19, and keeping written and photographic evidence of this, will reduce the risk of a fire spreading and help the business to stay safe and legal.

Risk management services for QBE customers

Depending upon the size and complexity of the business needs, QBE customers can access a team of in-house risk management experts, who can help formulate a tailored risk management approach for effective solutions and improved outcomes - including protecting employees, making claims less likely, and potentially reducing insurance premiums. You can find out more about how QBE helps businesses to manage risk at

Need to claim? Report it early

Finally, a reminder that if you have an incident and need to make an insurance claim, it’s important that you report it as soon as possible, ideally the same day. Reporting a claim early can save time and help you to receive any claim payments faster.


About QBE

QBE European Operations is part of QBE Insurance Group, one of the world’s leading international insurers and reinsurers and Standard & Poor’s A+ rated. Listed on the Australian Securities Exchange, QBE’s gross written premium for the year ended 31 December 2018 was US$13.7 billion.

As a business insurance specialist, QBE European Operations offers a range of insurance products from the standard suite of property, casualty and motor to the specialist financial lines, marine and energy. All are tailored to the individual needs of our small, medium and large client base.

We understand the crucial role that effective risk management plays in all organisations and work hard to understand our clients’ businesses so that we offer insurance solutions that meet their needs – from complex programmes to simpler e-trading solutions – and support them in minimising their risk exposures. Our expert risk management and rehabilitation practitioners focus on helping clients improve their risk management so that they may benefit from a reduction in claims frequency and costs.

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