Phoenix Journal · Extraction
Every commercial kitchen extract certificate is written in a trade shorthand few operators are ever taught. This glossary translates it - term by term, standard by standard.
The plain-English decoder
There is a moment, somewhere between the quote landing in your inbox and the engineer arriving on site, when a kitchen manager quietly wonders what half the words on the page actually mean.
TR19 Grease. Wet film thickness. TExT. Access panels at prescribed centres. It reads like a trade in code, and to a point it is - decades of fire investigations, insurance clauses and ventilation engineering compressed into a shorthand that everyone in the industry uses and almost nobody explains. That silence is a problem, because these are the exact terms that appear on your compliance certificates, your insurance schedule and, if things ever go wrong, the loss adjuster's report.
So here is the glossary we wish every operator had on day one. Not a dictionary to be read cover to cover, but a working guide to the language of commercial kitchen ventilation - what the words mean, which standard or regulation sits behind them, and why each one earns its place on the paperwork you sign.
Most of the jargon you meet traces back to a handful of published documents and the organisations that maintain them. Learn these anchor points and the rest of the vocabulary starts to fall into place, because almost every term is really a reference to a clause somewhere in one of them.
When a certificate cites a standard, it is telling you which rulebook the work was measured against. The names look interchangeable at a glance; they are not. Each governs a different part of the system, and confusing them is how a building ends up with beautiful ductwork drawings and a grease fire risk nobody measured.
A standard on its own is guidance. What gives these terms teeth is the regulation and the competent person standing behind them. It helps to know which name on your paperwork carries legal weight and which is simply best practice.
BESA writes the technical specifications but does not police your kitchen. The obligations that a court or an insurer will hold you to sit in law - principally the Regulatory Reform (Fire Safety) Order 2005, which makes the responsible person accountable for fire risk, and the Control of Substances Hazardous to Health Regulations 2002, known universally as COSHH. When an engineer describes themselves as competent, that too has meaning: for ventilation testing it typically means training recognised by the British Occupational Hygiene Society, such as the P601 qualification, rather than a self-declared title.
The second cluster of jargon is the practical stuff - the readings an engineer takes, the tests they run and the physical parts they need to reach. This is the language that decides whether a system passes or fails, so it is worth understanding what each number is actually describing.
Kitchen extract cleaning lives or dies on a single measurement: how much grease is left on the metal, expressed in microns. A micron is a thousandth of a millimetre, which sounds trivial until you remember that grease is fuel and ductwork is a chimney. TR19 Grease turns that fear into figures you can audit.
The point of all this arithmetic is that "clean" stops being an opinion. A pre-clean reading, a post-clean reading and a photograph turn a vague reassurance into evidence you can hand to an insurer without flinching.
The rest of the terminology is physical - the components an engineer needs to reach and the airflow they are trying to protect. These are the words that explain why a job takes the shape it does, and why "we cleaned the filters" is not the same as cleaning the system.
Two acronyms deserve a final word because they carry statutory weight rather than merely good-practice weight. Under COSHH Regulation 9, extraction that controls a hazardous substance must undergo a Thorough Examination and Test - shortened to TExT - carried out at intervals not exceeding fourteen months for most systems. This is LEV testing, where LEV stands for local exhaust ventilation, and the HSE's guidance sits behind it. An engineer measures whether the system still captures fumes at the design airflow and issues a report with a clear indication of what, if anything, needs putting right.
None of these terms is difficult once someone explains it plainly. What matters is that they connect: the standard defines the number, the test produces the reading, the access panel lets you take it, and the certificate records that you did. Keep those threads straight and the paperwork on your desk stops being a foreign language and starts being what it should be - proof that your kitchen is safe. If you would like the whole picture joined up rather than piecemeal, it is worth building a single ventilation cleaning compliance plan so every term above maps to a date, a reading and a document.
Questions
They govern different things and are easy to confuse. DW/144 is the BESA specification for how sheet metal ductwork is manufactured and installed - the physical fabric of the system, including smooth internal surfaces and sealed joints. TR19 Grease is the specification for how clean that ductwork must be kept internally, measured in microns of grease. In short, DW/144 builds the duct and TR19 Grease keeps it safe to use.
No, and one does not replace the other. An extract clean removes grease from the ductwork and is verified against the TR19 Grease standard. LEV testing, or a Thorough Examination and Test under COSHH Regulation 9, checks that the system still captures cooking fumes at the correct airflow and is typically required at intervals not exceeding fourteen months. A well-run kitchen needs both: cleaning for fire risk, LEV testing for the air your staff breathe.
Phoenix Duct Clean · by the numbers
The right kit only helps if the system stays clean. Phoenix degreases canopies, filters and ductwork to TR19 Grease - UK-wide, overnight.