COSHH 2002 · LEV

Dust extraction system testing and examination

Independent thorough examination and test of your dust extraction system as local exhaust ventilation, by a P601 qualified engineer.

A dust extraction system is only as good as its weakest duct. If the air in the ducting slows below the speed that keeps dust airborne, the dust drops out and settles where you cannot see it, starving the hoods and building a fire risk. We measure the system end to end, not just at the fan.

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  • Independent and impartial
  • Competent engineer surveyors
  • Reports issued promptly
Whole systemPickups, ducting, collector and fan, end to end
Transport velocityDucts must keep dust airborne, not let it settle
Hidden blockagesSettled dust builds unseen in opaque ducting
Combustible dustA fire and explosion risk, not only a health one
Extraction we test

Why your dust extraction system needs LEV testing

A dust extraction system draws dust from several machines at once, along ducting to a collector such as a cyclone or baghouse, through a fan and out to a safe discharge. The dusts it handles, wood dust, flour, silica and the like, are hazardous to breathe and some are carcinogenic, so COSHH treats the system as local exhaust ventilation and requires it to be thoroughly examined and tested rather than assumed to be working.

The weak point is the ducting. Dust needs roughly twenty metres per second moving through a duct to stay airborne, far more than a gas, and where a run is too slow the dust settles out and builds up unseen inside opaque ducting until a branch blocks and the machines on it lose their extraction. Settled combustible dust and a stray spark are also how a duct or a collector catches fire, so the test measures velocity through the system, looks for accumulation, and checks the collector and any spark protection.

Capture at each machine pickup
Duct transport velocity
Duct blockages and dead legs
Dust collector or cyclone
Filter or baghouse condition
Fan performance and discharge
Spark protection where fitted
Logbook and previous readings
How it works

How we test your dust extraction system

We measure the capture at each pickup and the air velocity through the ducting, so a branch that has slowed enough to let dust settle shows up before it blocks. We examine the ductwork for accumulation and dead legs, check the cyclone or baghouse and the fan, and look at the discharge and any spark protection, since a system carrying combustible dust has a fire risk to control as well as a health one.

  • 1

    Measure through the system

    We take capture at each pickup and velocity through the ducting, not a single reading at the fan.

  • 2

    Find the settling

    We examine the ducts for accumulation, dead legs and blockages where the air has slowed.

  • 3

    Check collector and discharge

    We examine the cyclone or baghouse, the fan, the discharge and any spark protection, then report.

Why businesses choose SEIS

  • P601 qualified | Tested by an engineer qualified in LEV thorough examination and test.
  • End to end | Pickups, ducts, collector and fan examined as one system, where the faults actually hide.
  • Velocity, not just volume | Duct transport velocity measured, the thing that keeps dust moving instead of settling.
  • Fire risk noted | Where the dust is combustible, the spark protection and discharge are checked, not assumed.
What we test

Dust extraction system: what a thorough examination and test covers

The duct you cannot see into

Settled dust builds quietly inside opaque ducting, starving the hoods on that branch long before anything shows on the outside. Measuring velocity through the run is how it is caught.

Twenty metres a second, not five

Dust needs roughly twenty metres per second in the duct to stay airborne, far more than a gas. A duct sized or run too slow drops its load and blocks.

The collector concentrates the risk

A cyclone pulls the heavy particles out and leaves the finest, most explosive dust gathered in the collector. That is exactly where a stray spark does the most harm.

A spark from a tool

A hot fragment drawn off a grinder can travel the duct and reach a collector packed with combustible dust. Spark protection is there to stop it, and it is checked, not taken on trust.

One blocked branch, several exposed

A blockage on one leg does not announce itself. The machines on that branch quietly lose their extraction while the fan still sounds healthy.

Health and fire together

Wood dust, flour and silica are hazardous to breathe and able to ignite. The same system has to control exposure under COSHH and explosion risk under DSEAR.

Intervals and certification

How often, and what you receive

A dust extraction system in regular use is thoroughly examined and tested at least every fourteen months, and sooner where the dust is carcinogenic, the loading is heavy or a risk assessment calls for it. The test confirms the system still captures at each pickup and carries the dust to the collector, against the performance it was designed to give.

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

Dust extraction system 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

Dust extraction system testing: common questions

How often does a dust extraction system need testing?
At least every fourteen months under COSHH Regulation 9, and sooner where the dust is carcinogenic or the system is in heavy use. The HSE sets the expectation in its guidance on local exhaust ventilation.
Why measure the velocity in the ducts?
Because dust needs roughly twenty metres per second to stay airborne. Below that it settles inside the ducting, out of sight, starving the hoods on that branch and building a fire risk, so duct velocity is central to the test.
What sorts of dust does this cover?
Wood dust, flour, silica, metal dusts and similar, all of which are hazardous to breathe and several of which are carcinogenic or able to ignite.
Is there really a fire risk?
Yes. Fine combustible dust settled in ducting or gathered in a collector can ignite from a stray spark, which is why the system falls under DSEAR for explosion risk as well as COSHH for health.
What is a cyclone or baghouse?
They are dust collectors. A cyclone spins the heavier particles out, and a baghouse or cartridge filter captures the finer dust before the cleaned air reaches the fan and discharge.
What do I receive after the test?
An LEV test report with the measured capture and duct velocities, the verdict and any remedial actions, plus a dated label. The duties behind it are set out in our guide to COSHH.
Can a single blockage really matter?
Yes. A blockage on one branch quietly removes the extraction from the machines on it while the fan still sounds healthy, which is why the test follows the dust through the whole system.
How do I book a dust extraction system test?
Call us on 0330 043 8191 and we will arrange a visit, measure the system end to end and have your report with you within a few days.

Is your dust extraction system 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