TR19 Air - Specification for internal cleanliness and hygiene management of ventilation systems – March 2026

TR 19® Air sets out best practice standards for the cleanliness of ventilation systems in commercial and public buildings. Published by the Building Engineering Services Association (BESA), it addresses the increasing emphasis on indoor air quality and its impact on health, comfort, and safety.

Purpose:

This updated specification provides detailed guidance on the cleaning, maintenance, and verification of internal ductwork cleanliness. It helps building owners, operators, contractors, and consultants meet legal obligations under the Workplace (Health, Safety and Welfare) Regulations, BS EN 15780, and other relevant standards.

Key Features:

• Defines measurable cleanliness levels for new and existing ductwork systems.
• Covers risk assessment, inspection, testing, and cleaning methodologies.
• Updated to reflect new standards and best practices for indoor air hygiene.
• Emphasizes risk reduction related to airborne particulates, fire hazards, and microbiological contamination.
• Applicable to new construction, refurbishment projects, and regular system maintenance.

Update includes:

TR19® Air now references the requirements of the Ventilation Hygiene Register (VHR). Details on Post clean reporting have now been included, as a new section (section 9). Changes are made to reflect the recently issued update to BS EN 15780 Details have been added on ductwork sensors. Whilst this is short due to the relative newness of the technology, their adoption is expected to grow in the future.

These main changes have been made to sections 4, 8.9 and 11 & Appendix A (to reflect changes to Appendix F of BS EN 15780).

Important Note:
The fire risk management of grease accumulation in kitchen extract systems is now covered separately under TR19® Grease.

Who Should Use This Guide:

Ideal for building services engineers, facilities managers, maintenance contractors, specifiers, consulting engineers, and specialist air hygiene companies.

Are you part of the UK’s Vent Hygiene Register (VHR)?

The Vent Hygiene Register is the recognised scheme for demonstrating compliance, evidencing technical standards, and gaining business opportunities in the ventilation hygiene sector.

Join The Vent Hygiene Register

Launching March 3rd 2026, VHR are expanding the Register to cover TR 19 Air not just Grease. You can learn more & register your interest below.

Learn More

Published Date: 03/03/2026
Number of Pages: 62
ISBN: 978-1-7391873-1-6
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Training: BESA Certified Air Hygiene Courses 

BESA Academy have also updated their range of air hygiene courses to reflect the updated TR 19® Air requirements and recommendations.

Ensure your operatives or technicians are trained to deliver a service to the highest of standards. And don’t put your business or your clients at risk.

To find out more about the courses available, visit the BESA Academy website.