What Thorough Examination and Test Means for LEV

What a thorough examination and test involves, step by step

HSG258 breaks a TExT into three connected parts - a thorough examination, a measurement of technical performance, and an assessment of whether exposure is actually being controlled. In practice a competent examiner works through the following.

1. Reviewing the design intent first. Before touching a single duct, the examiner establishes what "good" looks like for your system. That means reading the commissioning report, the user manual and the logbook that should have been supplied when the system was installed, so there is a benchmark - original airflows, capture velocities and fan settings - to test today's readings against.
2. Examining the whole system thoroughly. A visual and physical examination runs the full length of the installation, from canopy and grease filters through ductwork to the fan and discharge point. The examiner is looking for damage, corrosion, blocked or missing filters, disconnected sections, grease build-up, worn fan belts and anything that would stop the system working as intended.
3. Measuring capture at the hood. The point of extraction is to catch contaminant at source, so the examiner measures face and capture velocities across the canopy. For a kitchen canopy this confirms that fumes rising off the cooking line are drawn in rather than spilling into the room and the staff working there.
4. Measuring the technical performance inside the system. Duct velocities, static pressures and fan performance are recorded at set points and compared against the commissioning figures and manufacturer data. A drop against the benchmark is often the first hard evidence that grease is narrowing the ducts or that the fan is tiring, long before anyone notices a problem in the kitchen.
5. Testing control qualitatively. Numbers alone do not prove containment, so the examiner adds qualitative checks - typically smoke or dust-lamp techniques - to watch how air actually moves and whether contaminant is genuinely captured and carried away during representative activity rather than escaping back towards people.
6. Judging whether exposure is adequately controlled. The examiner pulls the evidence together into a single professional judgement: is the LEV, as found and in normal use, keeping exposure to a safe level? This is the assessment that connects the hardware back to your COSHH risk assessment and the exposure it was meant to control.
7. Issuing a clear, written report with actions. You receive a report that records what was examined, the readings taken, photographs, hood labels or performance indicators, a pass or fail against each function, and specific remedial actions with timescales. A credible report tells you not just that something failed, but what to do and by when.

Why the detail matters - and what a good report gives you

The reason HSG258 insists on all three parts is that each catches a failure the others miss. A canopy can pull a healthy face velocity while a grease-choked duct quietly strangles the system downstream; a fan can spin happily while contaminant spills sideways out of a badly positioned hood. Only by examining condition, measuring performance and testing control together can an examiner say, with evidence, that your kitchen extraction is still protecting people. That is the difference between a certificate and a genuine thorough examination and test.

Competence is central to the whole exercise. The regulations require the work to be done by a competent person, and the recognised route in the UK is BOHS training - the P601 qualification for LEV examination and testing. An examiner working to that standard knows how to interpret readings against commissioning data rather than simply confirming that air is moving. When you commission a TExT, it is reasonable to ask what qualification the examiner holds and to see it named on the report.

The output is a document, not just a visit, and it carries duties of its own. You must keep the report and make it available, and records should be retained for at least five years. It sits alongside your wider paperwork - the extraction TExT is one of the things an inspector expects to find, so it is worth understanding the documents an HSE inspector will ask for and keeping them together. The examination also feeds back into your risk paperwork, because the "adequately controlled" verdict only means anything against the exposures you identified when your COSHH assessment was actually done.

On timing, treat the 14-month figure carefully. It is a legal maximum for most systems, not a target, and HSG258 sets shorter intervals for certain higher-risk processes - some as frequent as monthly or six-monthly. For a busy kitchen, the practical driver is grease: heavy use loads filters and ducts quickly, so many operators examine and clean on a tighter cycle than the statutory ceiling. A TExT that comes back with a clean bill and a sensible interval is also your evidence that the routine cleaning and maintenance in between are keeping pace.