LEV Testing Explained: COSHH Reg 9 and the 14-Month Rule

Do I Need LEV Testing? (Short Answer)

If your workplace uses local exhaust ventilation (LEV) — extraction at source, such as a downdraught bench, a fume hood, a welding fume extractor, or dust extraction on a saw — then yes, you must have it thoroughly examined and tested at least once every 14 months. This is a legal requirement under the Control of Substances Hazardous to Health Regulations 2002, and the test must be carried out by a competent person.

LEV (local exhaust ventilation) is engineering control that captures airborne contaminants — dust, fume, mist, or vapour — at or near the point where they are released, before workers breathe them in. Because it is a control measure people rely on for their health, the law requires you to prove it still works. The rest of this guide explains the 14-month rule, what a test involves, and what records you need.

What COSHH Regulation 9 Actually Says

The duty comes from Regulation 9 of COSHH. It requires that "every employer who provides any control measure" keeps it "in an efficient state, in efficient working order, in good repair and in a clean condition" — and for LEV plant specifically, it sets a maximum interval between thorough examinations.

Regulation 9(2)(a) requires a thorough examination and test of LEV plant "at least once every 14 months," except for certain processes listed in Schedule 4 of the regulations, which have shorter intervals. So 14 months is the standard maximum for general LEV; some high-risk processes must be tested more often.

Why 14 months, not 12?

The 14-month interval is deliberate. It lets you book the test at the same time each year and still stay inside the legal limit even if scheduling slips by a few weeks. Treat it as a hard ceiling, not a target — many employers test annually to keep it simple, which also stays comfortably within the rule.

What a Thorough Examination and Test Covers

An LEV thorough examination and test (sometimes called a TExT) is more than a quick look. A competent examiner will typically:

Visually inspect the whole system — hoods, ducting, fans, filters, and discharge points — for damage, wear, blockages, and leaks.
Measure airflow at the capture points to confirm the system is drawing contaminants in effectively where the work happens.
Take static pressure readings through the system to identify blockages or fan problems.
Check filters and discharge to confirm captured contaminant is being dealt with safely and not recirculated.
Assess whether the system still controls exposure for the way the work is actually done now — not just how it was set up originally.

The examiner produces a report stating whether the LEV is performing as it should, and flagging any defects that need fixing.

Who Can Carry Out the Test?

The test must be done by a "competent person." In practice, LEV examiners usually hold the BOHS P601 qualification ("Thorough Examination and Testing of Local Exhaust Ventilation Systems"), which demonstrates they have the training to assess airflow and control performance properly. A general handyman switching the fan on and listening to it is not a thorough examination.

How Long to Keep LEV Records

You must keep a record of each examination and test, and of any repairs that follow. Regulation 9(4) requires that the record "or a suitable summary thereof shall be kept available for at least 5 years from the date on which it was made."

Keep the reports somewhere you can find them — an inspector will ask for the most recent LEV report, and you want to be able to show a clean history of testing and any defect fixes.

LEV Is One Control in the Hierarchy

It is worth remembering where LEV sits. Under COSHH, you should first try to prevent exposure (eliminate or substitute the substance), then control it at source — and LEV is a control-at-source measure. It comes before relying on respiratory protective equipment (RPE) such as masks. If you find yourself depending on RPE because the extraction is poor, the answer is usually to fix or improve the LEV, not to buy better masks.

LEV testing is also a good prompt to review the relevant COSHH assessment: if the test shows the system no longer controls exposure for how the work is now done, your assessment needs updating too.

Quick LEV Compliance Checklist

Identify every LEV system in the workplace
Book a thorough examination and test at least every 14 months (sooner for Schedule 4 processes)
Use a competent examiner (typically BOHS P601-qualified)
Fix any defects the report flags
Keep the report and repair records for at least 5 years
Carry out routine checks and maintenance between tests
Review the related COSHH assessment if the test shows control has dropped

Keeping Test Dates From Slipping

The most common LEV failure is not a broken fan — it is a test that quietly went overdue because nobody was tracking the date. Once you have more than one or two systems, or more than one site, the 14-month dates are easy to lose.

COSHHmate is being built to track your control measures and the dates that matter alongside your COSHH assessments, so an overdue LEV test surfaces before it becomes a compliance gap. Pricing will be a flat monthly fee with no per-user charges. To get your COSHH compliance properly organised, join the waitlist.

Sources

This is general guidance based on the COSHH Regulations 2002 and published HSE guidance. Testing intervals for some processes (Schedule 4) are shorter — check the regulations and your examiner's advice for your specific plant. Not legal or safety advice.