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Case study · Construction trades · Mobile LEV
A painting and decorating firm brought its whole fleet of on-tool dust extractors into its Hull unit for examination - twenty portable units that go out on vans every day. Testing a fleet is a different exercise from testing a fixed system, and the result was a genuine mix: most passed, several did not, and a few had to be taken out of service.
The site
The firm carries out painting and decorating across the region, and its operatives use on-tool dust extractors - portable units paired with sanders and other power tools to capture dust at source. Twenty of them were brought into the company's Hull unit to be examined together, off the vans for once and all in one place.
Testing a fleet is a different job from testing a fixed installation. There is no single system to measure; there are twenty individual controls, each with its own history of use and abuse, each needing to be judged on its own. Some had clearly been looked after; others had been run hard and rarely opened up. The brief was to work through every unit and produce an honest register: which were fit to go back out, which needed work, and which should not be used at all until sorted.
It is exactly the kind of equipment that slips through the net. Because the units are small, mobile and taken for granted, they are easy to leave off a testing schedule entirely - yet each one is the thing standing between an operative and a lungful of dust.
The hazard and the law
Preparation is dusty work, and some of that dust is genuinely hazardous. Sanding filler and plaster can release respirable crystalline silica; sanding old paint can release lead, especially from pre-1992 coatings and older; and there is fine preparation dust throughout. A portable extractor used to control that dust is local exhaust ventilation, and it carries the full Regulation 9 duty under COSHH - a thorough examination and test at least every 14 months, with a record kept, for every unit.
The twist that catches people out is filtration class. Extractors are graded L, M and H: M-class (at least 99.9% efficient) for medium-hazard dust such as wood and silica-bearing materials, and H-class (at least 99.995%) for high-hazard dust such as lead paint. Use a class below what the dust demands and the unit does something worse than nothing visible - it collects the coarse dust and returns the finest, most dangerous fraction to the air the operative is breathing. A unit can be working perfectly and still be the wrong tool for the job.
What we tested
We examined all twenty units individually. For each, we measured the airflow or suction against its rated figure, opened up and assessed the filter condition, and confirmed the filtration class was appropriate for the dust that unit is actually used on - the point where a good extractor can still be the wrong one. We checked the hose and connections, looked for any airflow indicator, and recorded a clear pass or fail for the unit.
The output of a fleet examination is a register rather than a single verdict: a line for every unit, saying whether it is fit for use, what it needs if not, and whether it should be withdrawn. That register is what lets the firm manage the fleet properly rather than hoping the kit on the vans is all fine.
What we found
| Units | Finding | Result |
|---|---|---|
| 15 units | Suction to rating, filters serviceable, class appropriate | Pass |
| 3 units | Filters blinded - suction collapsed | Fail |
| 1 unit | Only L-class but used on silica-bearing dust | Fail |
| 1 unit | Damaged hose - loss of capture | Fail |
Three-quarters of the fleet passed: suction to rating, filters serviceable, the right class for the work. The five that failed told the ordinary story of portable kit run hard - three with filters so blinded their suction had collapsed, one that was only L-class yet being used on silica-bearing dust (capturing the coarse and returning the fine), and one with a damaged hose leaking capture. Each failed unit was tagged out of service so it could not quietly go back on a van, and the register recorded exactly what each needed.
The remedial actions
The outcome
The firm came away with a complete register of its twenty units, five of them withdrawn and specced for fixing, and - just as valuable - a routine to keep the fleet honest between tests. The examination turned a cupboard of assorted extractors into a managed set of controls with a known status each.
Portable LEV is still LEV, and it fails in ways you cannot see or hear: a blinded filter still roars, an under-class unit still collects dust, a split hose still switches on. On a van, there is no gauge and no one measuring. The answer is unglamorous but effective - keep a register of every unit, test the fleet every 14 months, match the filter class to the worst dust each unit meets, and build a pre-use check into the day. It is how a decorating or construction firm turns "the kit's probably fine" into something it can actually prove.
Sources and further reading
The duties, exposure limits and control standards described here come from the Health and Safety Executive. For your own process, always work from the current HSE guidance:
Questions
Yes. A portable or mobile extractor used to capture dust at a power tool is local exhaust ventilation, and it is subject to the same COSHH Regulation 9 duty as a fixed system - a thorough examination and test at least every 14 months, with a record kept. It is a common blind spot: because the units are small and move around, they are easy to overlook, but the law treats them as the control they are.
More than people think. Sanding filler and plaster produces dust that can contain respirable crystalline silica; sanding old paintwork can release lead from pre-1992 coatings, and much older paint can be heavily leaded; and there is general fine dust from preparation throughout. Some of this is genuinely hazardous, which is why the grade of extractor - and whether it matches the dust - matters so much.
They are filtration classes. L-class is for low-hazard dust, M-class (at least 99.9% efficient) for medium-hazard dust such as wood and silica-bearing materials, and H-class (at least 99.995%) for high-hazard, carcinogenic or toxic dust such as lead paint. Using a lower class than the dust requires means the unit captures dust and then blows the finest, most harmful fraction straight back into the air.
Each unit is examined individually: we measure its airflow or suction against the rated figure, inspect and assess the filter condition, confirm the filtration class is right for the dust it is used on, check the hose, connections and any airflow indicator, and record a pass or fail per unit. A fleet test produces a register - which units are fit for use, which need work, and which should be taken out of service.
The usual reasons for portable kit: filters blinded with fine dust so suction had collapsed, a couple of units being used on silica-bearing dust while only L-class, and a damaged hose. None of these is dramatic on its own, but each means a unit that looks and sounds like it is working is not actually controlling the dust - and on a van, nobody is measuring.
Keep a register of every extractor, test the fleet on the 14-month cycle, replace filters before they blind rather than after, match the filtration class to the worst dust each unit sees, and build a simple pre-use check so operatives notice a drop in suction on site. Mobile LEV fails quietly; a register and a routine are what catch it.
Tell us your capture points and the process they control, and we will quote the thorough examination and test to COSHH and HSG258.
