You may have seen both "TR19" and "NAAD21" mentioned in kitchen extract cleaning. They're related, not competing — and most professional cleans now reference both.
TR19
TR19 is published by BESA and is the long-established UK standard for the fire-risk management of grease in kitchen extract systems. It's the document most Cardiff insurers and fire-risk assessors reference. Read more in our TR19 guide.
NAAD21
NAAD21 (current version NAAD-21:2025) is published by NAADUK, the National Association of Air Duct Specialists. It covers similar ground with a slightly broader scope — Part 1 deals with grease in kitchen extract systems, Part 2 with indoor air quality in wider ventilation. It adds detail on grease-measurement methodology and photographic evidence.
Which one do I need?
In practice, the strongest position is documentation that references both. They overlap, and a clean carried out to TR19 standards with NAAD21-style measurement and evidence gives you the most robust record for insurance, fire-risk and EHO purposes. When you arrange a clean through us, the certification is designed to satisfy what your insurer asks for — get a free quote and we'll explain exactly what your records will contain.
Frequently Asked Questions
Does NAAD21 replace TR19?
No — they complement each other. Documentation referencing both gives the strongest compliance record.
Which do insurers ask for?
Most reference TR19, and increasingly NAAD21 alongside it. A clean documented to both covers you either way.