Kitchen extract systems rank among the most vulnerable parts of a building’s ventilation network. Unlike general supply or extract ducts, they operate in highly contaminated environments. During cooking, the ductwork continuously draws grease, oil vapours and airborne particulates through the system.
Many commercial kitchens operate for extended hours, which increases the volume of grease moving through the ventilation system. Without regular inspection and cleaning, grease buildup can escalate quickly. The confined and often concealed layout of ductwork makes it challenging to monitor internal conditions without a structured maintenance programme.
Reports from the insurance and fire safety sectors indicate that extract duct fires continue to be a leading cause of severe damage in commercial kitchens. These incidents can result in extended downtime, reputational damage, and legal consequences, notably when maintenance records or proof of compliance are missing.
Kitchen extract systems are therefore considered high risk. Teams must conduct frequent inspections, schedule regular cleaning, and verify afterwards that the system meets required hygiene standards. TR19® provides the framework for managing this risk and protecting people, property, and business continuity.
Owners and operators of commercial kitchens have a legal duty to maintain safe and hygienic ventilation systems. Several regulations and industry expectations reinforce this responsibility by governing fire safety, workplace health and safety, and environmental hygiene.
The Regulatory Reform (Fire Safety) Order requires responsible persons to assess and reduce fire risks in non-domestic premises. In the context of kitchen extract systems, this means identifying grease buildup as a fire hazard and implementing an appropriate cleaning schedule.
Failure to comply with this obligation can result in legal action, including enforcement notices or prosecution. In the event of a fire, investigators often request evidence showing that the team maintained the system in line with industry best practices, such as those outlined in TR19.
From an insurance perspective, many providers now require proof that kitchen extract ductwork undergoes regular cleaning and inspection. Failure to follow a recognised standard may lead insurers to deny claims when they trace the fire back to poor maintenance.
Documented compliance with TR19® offers a clear record of inspection and cleaning, which can be essential in demonstrating due diligence. Photographic evidence, deposit thickness test results, and detailed reports support both legal and insurance requirements.
By following TR19®, kitchen operators can manage their legal responsibilities, meet insurer expectations, and reduce the risk of costly disruptions.
TR19® sets out clear guidance on how often kitchen extract systems should be cleaned, based on usage levels and risk factors. The guidance establishes cleaning frequencies to prevent excessive grease buildup and support safe, efficient operation.
Cleaning teams determine appropriate intervals based on the number of hours the kitchen operates each day. TR19® recommends the following minimum cleaning frequencies:
These are minimum recommendations. More frequent cleaning may be required, depending on the type of cooking, the condition of the system, and the results of insurance and fire risk assessments.
In terms of cleaning methods, TR19® emphasises the need for comprehensive access throughout the duct system. The cleaning process encompasses the entire ventilation system, including the canopy, fan, and the full length of the ductwork. Teams must make previously inaccessible areas reachable by installing access panels at appropriate intervals.
Cleaning crews typically use mechanical scraping, manual wiping, and high-pressure wet or dry vacuuming. In heavily contaminated systems, they may also apply specialised chemical treatments, provided the products are suitable for food-safe environments.
Verification plays a central role in the TR19® process. Teams must take before-and-after photographs from identical positions to document cleaning outcomes. They can also perform Deposit Thickness Tests (DTT) to measure grease levels on internal surfaces and confirm compliance with acceptable limits.
Many operators still ask how often to clean commercial kitchen extract ducts. TR19® provides a risk-based frequency schedule and cleaning verification methods to support compliance.
By following these cleaning frequencies and methods, kitchen operators can ensure their systems remain safe, efficient, and compliant with industry expectations.
A well-structured cleaning contract ensures your kitchen extract system remains compliant with TR19 and other industry standards. It provides clarity between client and contractor, sets performance benchmarks, and supports legal and insurance compliance.
The contract should specify the following core elements:
By including these components, your cleaning contract will not only meet operational needs but also provide the documented evidence required to satisfy legal duties and insurance conditions. It reflects a commitment to best practice and protects all parties involved in managing kitchen ventilation hygiene.
Meeting hygiene standards is not a one-off task. Ongoing compliance with TR19® requires continuous monitoring, proper certification, and reliable record-keeping. This approach not only demonstrates a commitment to safety but also satisfies the expectations of insurers, regulators, and auditors.
The contractor must provide a full post-clean verification report after each completed clean. This report must include:
These documents offer traceable evidence that the system meets recognised best practice for maintenance. In the event of a fire or inspection, they form the first line of defence against legal liability or insurance complications.
It is equally important to maintain a cleaning log. Keep the documentation on-site or store it in an accessible system to maintain a complete record of inspection and maintenance. Digital systems can support this process by providing alerts for upcoming cleans and centralised storage of documentation.
TR19® also advises regular reviews of access points, system layout, and duct condition. As kitchens evolve, new appliances or layout changes may affect airflow patterns or create new areas of risk. Keeping your maintenance plan up to date is essential for staying compliant.
Many facilities partner with certified and experienced contractors to ensure consistent compliance with TR19® requirements. Doing so reduces risk and gives operators, tenants, and owners greater peace of mind.
By incorporating TR19 into your routine maintenance schedule, you can protect your business, meet legal obligations, and ensure long-term building safety.
Further Reading
For a deeper understanding of industry standards, read our TR19® Ventilation Hygiene Standards Guide, which explains how the specification supports compliance and safety across all ventilation systems.
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Improve Your Compliance with the TR19® Grease Guide
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Download the TR19® Grease Specification