COSHH 2002 · LEV

Fume cupboard testing and examination

Independent thorough examination and test of your fume cupboard as local exhaust ventilation, by a P601 qualified engineer.

A fume cupboard is only protecting the person in front of it if air is being drawn in across the whole sash opening, fast enough and evenly enough to carry vapour away from the breathing zone. We measure that, and we test whether the cupboard actually contains what is released inside it.

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  • Independent and impartial
  • Competent engineer surveyors
  • Reports issued promptly
Sash openingFace velocity measured across a grid, not at one point
ContainmentTracer gas shows what airflow alone cannot
Whole systemDuctwork and fan examined, not just the cabinet
Every 14 monthsThe COSHH maximum for most fume cupboards
Extraction we test

Why your fume cupboard needs LEV testing

In a laboratory the fume cupboard is usually the main control between a person and the substance they are handling. It works by drawing room air in through the sash opening and away to a safe discharge, so the inward face velocity, and how evenly it is spread across the opening, is what keeps vapour out of the breathing zone. Performance drifts as fans wear, filters load and ductwork fouls, which is why COSHH treats the cupboard as local exhaust ventilation and calls for a thorough examination and test.

Airflow on its own does not prove safety. A cupboard can read a healthy face velocity and still spill contaminant back out under the right conditions, which leaves users protected in theory but not in practice. Containment testing settles the question by releasing a tracer gas inside the cupboard and measuring what escapes at the working face, so the result reflects what the cupboard actually does rather than what the airflow suggests it should do.

Sash mechanism and working height
Face velocity across the sash grid
Containment at the working face
Aerofoil sill and internal baffles
Airflow indicator or alarm
Ductwork, fan and discharge
Recirculating filter condition
Logbook and previous test data
How it works

How we test your fume cupboard

We set the sash to its marked working height and take face velocity readings across a grid of points at the opening, recording the individual values along with the average, minimum and maximum so any weak corner shows up rather than being averaged away. Where containment matters we follow with a tracer gas test, then examine the cupboard, its ductwork and fan as one system before recording the result.

  • 1

    Set up and measure

    We note the cupboard, set the sash to its working height and measure face velocity across the opening against its design value.

  • 2

    Test containment

    Where the work warrants it, we release tracer gas inside and measure escape at the face, the truest check of control.

  • 3

    Examine and record

    We examine the sill, baffles, monitor, ductwork and fan, then label the cupboard and issue the report.

Why businesses choose SEIS

  • P601 qualified | Your cupboard is tested by an engineer qualified in LEV thorough examination and test.
  • Measured at the sash | Face velocity across the opening and containment at the face, not a single reading at the centre.
  • The whole cupboard | Sash, sill, monitor, ductwork and fan examined together, the way the standard intends.
  • Plain reporting | A clear report with the numbers, the verdict and any remedial work, within days.
What we test

Fume cupboard: what a thorough examination and test covers

The grid, not the middle

One central reading can pass while a corner of the sash sits well below the design value. Measuring across a grid is how an uneven face is found.

Containment a monitor misses

A cupboard with a working alarm can still fail a tracer gas test. Until containment is measured, a green light is reassurance, not proof.

Ducted or recirculating

A ducted cupboard is examined to BS EN 14175 through to its fan and discharge. A recirculating filter cupboard is judged on filter condition and breakthrough to BS EN 17242.

Sash height discipline

The working height is marked for a reason. A sash raised above it drops the face velocity and quietly removes the protection the cupboard was set up to give.

Schools and colleges

Teaching laboratory cupboards are tested to the same principles, with CLEAPSS guidance applied to the lower hazard work they are built for.

A system, not a box

Most real failures sit in the ductwork or the fan, out of sight above the ceiling. Examining the cabinet alone leaves the most likely fault untouched.

Intervals and certification

How often, and what you receive

For most laboratory fume cupboards the thorough examination and test falls due at least every fourteen months, with shorter intervals where the work is higher hazard or a risk assessment calls for it. The test compares the face velocity, and where needed the containment, against the values the cupboard was commissioned to hold.

14 monthsThe usual maximum interval for a thorough examination and test
MeasuredAirflow and capture tested at every hood, not just the fan
P601Examined by an engineer qualified in LEV testing
ReportedMeasured data and any remedial actions, in writing

You receive an LEV test report with the measured performance and any remedial actions, the record COSHH requires.

Full statutory cover

Part of our full COSHH inspection service

Fume cupboard is one of the many kinds of equipment we cover. We inspect the full range, across every sector, as an independent provider, one item or a whole site, anywhere in the UK.

See our full COSHH inspection service
Other services

Other statutory inspections we carry out

Many sites run more than one regime. We can examine all of it, under one independent provider.

LOLER inspectionThorough examination and certification of lifting equipment and accessories. PUWER inspectionInspection of work equipment against the five PUWER duties, with a written record. PSSR examinationWritten Schemes and certified examination of pressure systems.
COSHH FAQs

Fume cupboard testing: common questions

How often does a fume cupboard need a thorough examination and test?
For most fume cupboards the maximum interval is fourteen months under COSHH Regulation 9, and shorter where the substances are higher hazard or a risk assessment calls for it. The HSE sets this out in its guidance on local exhaust ventilation.
Is measuring the face velocity enough?
It is necessary but not sufficient. A cupboard can show an acceptable inward velocity and still let contaminant escape at the face, so where the work warrants it we confirm performance with a tracer gas containment test.
What face velocity should my fume cupboard have?
The value it was commissioned to hold is the one that matters. As a common benchmark, around 0.5 metres per second at the marked working sash height is expected for standard hazardous work, with 0.3 to 0.5 acceptable for lower risk use.
My cupboard recirculates rather than ducting outside. Does that change the test?
Yes. A ducted cupboard is examined through to its fan and discharge to BS EN 14175, while a recirculating filter cupboard is judged mainly on filter condition and breakthrough to BS EN 17242.
Do you examine the ductwork and fan, or only the cabinet?
The whole system. Most genuine failures sit in the ductwork or the fan above the ceiling, so we examine the cabinet, its ducting, the fan and the discharge as one, which is what a thorough examination requires.
What do I receive after the test?
An LEV test report with the measured face velocity, any containment result and the remedial actions, plus a dated label on the cupboard and an entry in your logbook. You can read what the law requires in our guide to COSHH.
Can you test fume cupboards in schools and colleges?
Yes. Teaching laboratory cupboards are tested to the same principles, with CLEAPSS guidance applied to the lower hazard work they are designed for.
How do I book a fume cupboard test?
Call us on 0330 043 8191 and we will arrange a visit, carry out the examination and test, and have your report and label with you within a few days.

Is your fume cupboard due an LEV test?

Talk to an engineer surveyor, get a quote and book your inspection anywhere in the UK.

0330 043 8191 Request a quote