LEV thorough examination and test
The thorough examination and test, often shortened to TExT, is the statutory check of a local exhaust ventilation system under regulation 9 of COSHH. It has to happen at least every 14 months, and it is the paperwork an HSE inspector asks for first when they see extraction in a workshop.
For a small system with one or two hoods expect around £150 to £300 excluding VAT, then roughly £25 to £60 for each further hood or point on the same visit.
- Longest interval
- 14 months
- Keep the reports
- 5 years
- First small system
- £150 to £300
Who needs a thorough examination and test
Any employer whose risk assessment relies on extraction to control a hazardous substance. That covers dust extraction on woodworking machines, welding fume arms and hoods, fume cupboards, spray booths, grinding and polishing hoods, oil mist extractors on machine tools, and on-tool extraction where it is plumbed into a system.
The interval is at least once every 14 months. A few processes listed in COSHH Schedule 4 must be tested more often: blasting to clean metal castings and jute cloth manufacture every month, and dry grinding or polishing of metal for more than 12 hours a week, and non-ferrous casting, every six months.
Portable units with their own fan count too. If the extractor is there to stop people breathing a substance, it needs testing whether it is fixed to the wall or on wheels.
Typical fees for a thorough examination and test
| Item | Typical fee, ex VAT |
|---|---|
| First system, one or two hoods Includes travel within a normal radius and the written report | £150 to £300 |
| Each further hood or extraction point Arms, machine connections, slots, booths on the same visit | £25 to £60 |
| Each further separate system A second fan and filter set on the same site, before its hoods | £60 to £120 |
| Retest after repairs Usually a short return visit for the failed hoods only | £100 to £200 |
Typical UK fees read from testing firms’ published prices, November 2026. A guide, not a quote.
What the examiner measures
HSG258 sets out the test in three stages: a thorough examination of the parts, measurements of how the system performs, and a judgement on whether it still controls exposure.
- Hoods and enclosures
Condition, position and whether the work actually happens inside the capture zone. A hood that is fine on paper but sits a metre from where the operator works will fail on the third stage.
- Capture and face velocity
Air speed at the face of a booth or cupboard, or at the point where the contaminant is released for a capturing hood, compared with the commissioning figure.
- Static pressure
Readings behind each hood and across the filter and fan. A drop in hood static pressure is the quickest sign that a duct is blocked or a damper has been moved.
- Duct velocity
Air speed in the ducts, which has to stay high enough to carry dust to the filter rather than letting it settle in the runs.
- Fan and filter
Fan speed, belts, motor current where relevant, filter condition and the pressure across it, and whether the discharge goes where it should.
- Visible checks
Smoke and dust lamp tests to see where the air really goes, and whether contaminant escapes the hood while the job is running.
Test due soon, or no report on file? Tell us about the system.
Get a quoteHow a test visit runs
Find the paperwork
before bookingThe commissioning report and the last test report give the examiner the benchmark figures. Without them the first visit has to set new ones, which takes longer.
Run the process
on the dayThe examiner needs the machines or process running normally for the third stage, so book a day when production is on rather than a shutdown.
Labels on every hood
at the end of the visitEach hood tested gets a label with the test date and the next due date. A hood that fails gets a red label and should not be relied on until it is fixed.
The written report
usually within two weeksResults for each hood against the benchmark, a schematic with test points, defects and what to do about them. File it with the logbook and keep it for at least five years.
What a good report contains
| Section | What to look for |
|---|---|
| Identification | Your name and address, the system reference, the date, and the examiner’s name and employer |
| Condition | The state of each part found on the day, and any adjustments made during the visit |
| Measurements | Velocities and static pressures at each test point, set beside the commissioning or previous figures |
| Control | A plain statement for each hood of whether it is controlling exposure, with the evidence |
| Defects | Each fault, what it means, and how soon it should be put right |
| Next test | The latest date for the next test, and a shorter interval if the examiner recommends one |
Asked before booking
Is LEV testing a legal requirement?
Yes. regulation 9 of COSHH requires an employer to have LEV thoroughly examined and tested at least once every 14 months, or more often for the processes in Schedule 4, and to keep a record for at least five years.
Why 14 months and not 12?
The extra two months give some slack to book a test around production. Most sites still test every 12 months so that the date stays in the same season each year.
Can our maintenance engineer do the test?
COSHH names no specific certificate, only competence. In practice HSE inspectors and insurers expect an examiner with BOHS P601, and someone independent of the people who maintain the system is better placed to judge it.
How long does a test take?
A single system with a few hoods is usually a morning. A joinery shop with a dozen machines or a lab with many cupboards can take a full day, plus the time to write the report.
What happens if a hood fails?
It gets a red label, and you should stop relying on it to protect anyone until it is repaired. Fix the cause, then have that hood retested. See our note on a failed LEV test.
What does it cost?
For a small system, usually £150 to £300 plus VAT. Larger sites pay less per hood. Our LEV testing cost guide has an estimator.
Related pages on LEV testing
- LEV testing cost guide and estimator
Work out a budget from the number of systems and hoods.
- LEV commissioning
The benchmark every later test is compared against.
- What goes in an LEV logbook
The weekly and monthly checks between tests.
Sources for this page
Fee bands are our own reading of what UK testing firms publish (2024 to 2026); we do not name or link them. The rules come from the regulations and official guidance below.
- COSHH 2002, regulation 9: maintenance, examination and testing of control measures
- COSHH 2002, Schedule 4: frequency of thorough examination and test of LEV in certain processes
- Control of Substances Hazardous to Health Regulations 2002 (SI 2002/2677), legislation.gov.uk
- HSE HSG258: Controlling airborne contaminants at work, a guide to local exhaust ventilation (3rd edition, 2017)
- HSE: LEV information for designers, installers and examiners
- HSE: Commissioning LEV
- BOHS P601: Thorough Examination and Testing of Local Exhaust Ventilation Systems
Get a quote for a thorough examination and test
Postcode first, then a few details about the system, then your contact details. Two minutes, start to finish.
Received. We are on it.
- Within a working day we contact you with the name of a qualified examiner who covers your postcode and tests this kind of extraction.
- They only see your details once you have said yes.
- They agree the hoods, the date and a written fee with you directly. There is no mailing list.