TR19 Guidelines

Maintenance of indoor ventilation is essential in keeping your building, staff and customers safe and healthy. Both kitchen grease ventilation and air handling ductwork require regular, expert cleaning to perform at their best, and remain legally compliant.

Rentokil Specialist Hygiene have over 50 years of experience in the ventilation cleaning industry, and provide a tailored, professional service around your operational requirements.

TR19 is a set of best practice guidelines created by BESA (Building Engineering Services Association), as a way to standardise extract and duct cleaning.

Originally introduced in 2005, BESA published two new, standalone standard documents between 2019 and 2020, one to help reduce the risk of fires in commercial kitchens, and another to standardise levels of cleanliness when cleaning air ventilation systems.

Both documents give guidance on proper installation, access, cleaning and maintenance for original installers and cleaning contractors alike.

In a commercial kitchen environment, the cooking process aerosolises fats, oils, and grease (FOGs). The building's industrial extraction system is designed to capture this grease-laden vapour and exhaust it externally into the atmosphere. Inevitably, grease will build up within the canopy and ductwork and, if not regularly cleaned, can create a significant fire risk. Grease within kitchen exhaust systems is one of the leading causes of hospitality fires in the UK, with around 70%of fire in commercial kitchens originate in faulty extract ventilation systems due to the build up of fat & grease.

Cleaning to TR19 Grease standards means removing grease to an accepted, safe level whenever it exceeds certain thresholds. A typical TR19 Grease cleaning job consists of:

Kitchen extract ductwork is often hidden above false ceiling panels, or within roof voids and plant rooms, making it difficult to reach.  In addition, in commercial kitchens the ducting can extend many metres behind false panels and vertically up external walls where gaining access is difficult. To comply with TR19 and in order to properly inspect and effectively clean grease, the system must be accessible.

• What's required? Access panels must be installed approximately every 2 metres along the ductwork.
• Why is it important? Without proper access, a thorough inspection and clean is impossible, leaving hidden grease deposits that pose a significant fire risk.

Before any cleaning begins, a detailed inspection is carried out to assess the current state of the system.

• Grease Measurement: Technicians use a Wet Film Thickness Test (WFTT) to measure the thickness of grease deposits in microns (µm). This test determines how much grease has accumulated and dictates the necessary cleaning frequency for your specific kitchen.
• Visual Record: Pre-clean images of each inspection point under TR19 are taken to allow a ‘before and after’ visual comparison. This provides a clear visual record of the system's condition prior to the clean.
• Recommendations: Any potential issues or necessary repairs are identified and reported at this stage.

Cleaning of grease from commercial kitchens relies on expert training, professional chemicals and cutting edge equipment, as well as plenty of elbow grease. Typical cleans involve manual scraping and wiping, applications of degreasant chemicals, and in some instances the use of remote access brushing equipment to remove grease from hard to reach areas. Cleans must remove grease levels back to less than 50 microns  as an average across the system, as specified in the TR19 guidelines.

Once the clean is carried out to a satisfactory standard, the clean is verified by taking post-clean photos, and the technician will conduct final WFTT measurements to confirm that grease levels are safely below the 50-micron threshold.

A detailed Post-Clean Verification Report (PCVR) is compiled. This report includes the before-and-after photos and measurement data, serving as evidence of the completed work.

A formal TR19 certificate of hygiene is issued through the Ventilation Hygiene Register (VHR), which you can use for insurance and legal compliance purposes.

Importantly, the schedule of cleaning and inspection will be based on your kitchen's requirements. Grease levels can fluctuate with seasonal menus, that's why our service will always reflect what the cleaning requirements actually are.

Updated in 2023 by BESA following the pandemic, TR19 Air addresses the urgent need for clean air ducts & the importance of wall-maintained ventilation. Poor indoor air quality has many negative consequences for a business including employee fatigue, increased absenteeism, and higher rates of short and longer term illnesses.

Dust, mould and bacteria can build up in a poorly maintained air ventilation system and are easily spread throughout a building if proper levels of hygiene and repair are overlooked. TR19 is the UKs recognised standard for cleanliness of indoor air ventilation systems and, similar to TR19 Grease, provides a recognised level of cleanliness and hygiene to be followed by customers and contractors. Regular TR19 Air inspections and cleaning can include:

Commercial building ventilation systems can be hundreds of metres in length, with access often restricted to false ceilings, walkways and plant room. To properly maintain these systems, full access is critical.

• What's required? Access panels should be strategically placed, typically every 15 metres and near key components like fans and filters.
• Why is it important? These panels are the only way for technicians to conduct thorough inspections and effectively clean the internal surfaces of the ductwork.

Frequency of inspection is based on the type of environment, with higher risk buildings such as hospitals requiring more frequent inspection. Before cleaning, a detailed inspection determines the level of contamination and sets a benchmark for the work.

• Dust Measurement: Technicians assess dust levels visually and use a Preferred Vacuum Test (PVT). This test measures the amount of debris to see if it exceeds acceptable safety levels.
• Visual Record: "Before" photos are taken inside the ducting. This provides a clear comparison point for the post-clean results and helps identify any maintenance needs.

Cleaning inside ducting is a highly specialist job, which requires industrial vacuums, negative air movers, HEPA filtration and long reach brush systems capable of cleaning to a high standard. Physical removal of all dry deposits is needed before the system can be handed over.

Once dust is removed to a level below accepted TR19 levels, a comprehensive report, including before and after photographs from key inspection points as well as a full schematic of the ventilation system is produced.

A TR19 certificate of cleanliness is issued, serving as proof that the system has been professionally maintained and complies with industry standards.

As the leading industry guidance, TR19 guidelines set a consistent, safe standard to be followed by commercial property owners and contractors to help prevent kitchen fires and supply clean, healthy air in the workplace. In kitchens, the accumulation of grease within extraction systems and ducting can diminish airflow and increase the risk of fire. TR19 Grease is a recognised standard for measuring grease levels and identifying recommended cleaning frequencies, which are designed to significantly reduce the risk of fire and are tailored to your system. Regularly clearing grease deposits can promote a good working environment by taking away heat from cooking to maintain a good supply of airflow and reduce the risk of kitchen fires.

In addition, many insurance policies contain conditions relating to cleaning regimes of kitchen extraction systems and if a fire occurs which is shown to be associated with inadequate cleaning of ductwork,  then it could jeopardise your right to indemnity for loss or damage.

Under the Regulatory Reform (Fire Safety Order 2005) and equivalent national cleaning legislation in Scotland and Northern Ireland, a requirement is placed on the ‘responsible person’ (owner, occupier or person with control) to make sure action is taken to prevent fires, which includes a ‘suitable and sufficient’ Fire Risk Assessment. Due to the high risk of potential fire, kitchen extraction systems warrant very close attention and best practice set out in BESA TR19 grease guidelines should inform this assessment, to help ensure that the grease extraction system in your commercial kitchen remains safe at all times.

In both grease extraction and air ventilation systems, regular maintenance is vital to ensure optimal performance and avoid costly running repairs or damage in the future. A clean ventilation system not only improves fire safety and air quality, it's vitally important to avoid expensive repairs or unnecessary replacements. A clean system also works far more efficiently, providing improved removal of grease or superior indoor air quality.

A proactive approach to TR19 compliance has numerous benefits to you and your business:

As an employer, you can take a huge step towards TR19 duct cleaning compliance by employing the services of an approved TR19 contractor. You can easily check whether your existing contractor is compliant by searching for them on the BESA member register.

You should ask your current service provider the following questions to determine if their service is TR19 compliant:

1. Do you provide a TR19 compliant post-clean report?
2. Are you a part of the Ventilation Hygiene Register (or equivalent) and therefore have access to the BESCA (Building Engineering Services Competent Assessment) portal, so that service can be registered and audited?
3. Have all of the technicians carrying out the work completed BESA approved training by a BESA third party approved training provider, to minimum Grease Hygiene Operative level, and hold an in date qualification?

If the answer is NO to any of the above, your service provider may not be providing a TR19 compliant service.

Rentokil Specialist Hygiene are proud members of BESA and fully signed up members of the Ventilation Hygiene Register.

TR19 Grease states that a system must be cleaned to its entirety to be fully TR19 compliant. Whether the system has had a ‘FULL CLEAN’ or a ‘PARTIAL CLEAN’ will be stated on the TR19 Certificate generated by the service provider in the BESCA VHR portal. Our technicians strive to insert access panels every 2m in accordance with TR19 guidelines. Where this is not possible, Rentokil Specialist Hygiene will use specialist remote brushing equipment to help ensure that we are able to clean systems in their entirety.

Rentokil Specialist Hygiene are the UK trusted experts for commercial kitchen cleaning.

• A ROSPA Gold award company
• Flexible working to provide ventilation cleaning around business opening hours
• Industry accredited GHT (Grease Hygiene Technician) and AHO (Air Hygiene Technician) qualified technicians to provide TR19 Grease and TR19 Air compliant cleans
• Members of the BESCA (Building Engineering Services Competent Assessment) Ventilation Hygiene Register and members of BESA (Building Engineering Services Association)
• Expert, consultant-led risk assessment on every job
• Safe waste disposal through licensed carriers
• Trust us to restore safety, hygiene, and peace of mind

Rentokil Specialist Hygiene are also trusted members of the Aviva Specialist Partner Network. As one of the UKs largest insurance providers, Aviva provides insurance for a large number of commercial kitchens. By partnering with Aviva we can offer customers significant discounts on commercial grease ventilation cleaning and help ensure that Aviva customers receive a professional and compliant TR19 service.

Whether a commercial kitchen extraction system clean, or the air ducting above your office, you can trust us to provide a professional TR19 compliant service. Call our friendly team of experts or contact us here 24/7/365 to arrange a comprehensive, no obligation survey of your ventilation system.