Phoenix Journal · LEV Testing
Years of breathing workplace dust can quietly lead to COPD long after the exposure happened. Here is how source extraction and respiratory protection compare - and why proving your controls work matters.
Occupational lung health
Chronic obstructive pulmonary disease rarely arrives overnight - it builds quietly over years of breathing air that never looked all that dangerous.
COPD is an umbrella term for long-term conditions, chiefly chronic bronchitis and emphysema, that narrow the airways and make it steadily harder to breathe. Most people still link it to smoking, and smoking is indeed the biggest single cause. But it is far from the only one. A growing body of evidence points to the workplace, and specifically to years of low-level exposure to dust, fume, vapour and gas that quietly scars the lungs long before anyone reaches for an inhaler.
The figures are sobering. Reviews of the international evidence put the population attributable fraction for COPD from workplace vapours, gases, dusts and fumes at roughly 14 to 15 per cent - in other words, around one in seven cases would not happen without the job. In the UK, the Health & Safety Executive estimates that some 12,000 deaths each year from lung disease are linked to past exposures at work, with COPD named as a contributing factor in a large share of them. The exposures that did the damage often happened decades earlier.
That long lag is what makes dust so easy to underestimate. A little haze in a workshop, a fine film on the surfaces, a cough that clears by Monday - none of it feels like an emergency. Yet the respirable fraction, the particles small enough to reach the deepest gas-exchange region of the lung, is doing cumulative harm you cannot see. Flour, wood, stone, welding fume, grain and cleaning aerosols have all been implicated across kitchens, workshops and production floors alike. So the real question for any employer is not whether to control dust, but how. Broadly, there are two routes - capture the dust at source, or protect the person breathing it. This article compares the two.
Local exhaust ventilation (LEV) is engineering control - a hood, capture point or enclosure that draws contaminated air away at the moment and place it is created, ducts it clear of anyone's breathing zone, cleans it and discharges it safely. It sits near the top of the COSHH hierarchy of control, well above personal protection, because it removes the hazard from the air rather than relying on the worker to defend against it. Done properly, nobody has to remember anything for it to work.
That drift is the catch worth dwelling on. Extraction that captured beautifully on day one can quietly fall away, and the first sign is often a loss of pull at the hood. If you have ever wondered why your dust extractor loses suction, the answer is usually blocked filters, leaking ductwork or a tiring fan - the same faults a statutory examination is designed to catch before exposures creep back up. Left unchecked, a system that no longer captures is arguably worse than none at all, because it lulls everyone into thinking the problem is handled.
Respiratory protective equipment (RPE) covers the masks and respirators worn on the face, from disposable filtering facepieces to powered hoods. It has an important role, but under COSHH it is explicitly the last line of defence - to be used only after elimination, substitution and engineering controls have been pushed as far as is reasonably practicable, and usually alongside them rather than instead of them.
The verdict is not really either/or. Best practice puts LEV first as the primary control and reserves RPE for the residual risk that engineering cannot reach. What tips the balance is evidence: an LEV system only earns its place at the top of the hierarchy if it is genuinely capturing what it should, and that is something you demonstrate rather than assume. The same logic applies whatever the dust - a joinery shop wrestling with wood dust, the workshop hazard that is easy to underestimate, or a commercial kitchen managing flour and cooking aerosols day after day.
Whichever route you take, the point of control is to keep the air people breathe below the legally binding limits in the HSE's EH40/2005 list of workplace exposure limits. These are the benchmarks a thorough examination measures your system against.
Note how tight the silica figure is - one hundred times lower than the 10 mg/m³ limit for general inhalable dust, and one you will not hold without effective capture at source. Numbers like these are why guidance such as HSG258 · Controlling airborne contaminants at work sets out what a well-designed system looks like, and why competent examiners hold recognised qualifications such as BOHS P601. COPD is a disease of accumulated small doses, so control that merely looks convincing is not enough - it has to be measured, recorded and kept honest year on year.
The long-term link between workplace dust and COPD is now well established, and the sensible response is not panic but proof - extraction that captures at source, backed by RPE only where it must be, and hard evidence that the whole arrangement still works. Protect the lungs today and you are protecting your people from a diagnosis that might otherwise land quietly, years down the line, long after the dust was forgotten.
Questions
Smoking is the single biggest cause, but it is not the only one. Reviews of the evidence attribute roughly 14 to 15 per cent of COPD cases to workplace exposure to dusts, fumes, vapours and gases - around one in seven. The HSE links thousands of UK lung-disease deaths each year to past exposures at work, with COPD a common contributing factor.
LEV comes first. Under the COSHH hierarchy of control, engineering controls that capture dust at source rank well above respiratory protective equipment, which is treated as the last line of defence. RPE has a genuine role for short tasks and residual risk, but it protects only the wearer and depends on correct fit and use, so it should support good extraction rather than replace it.
Under COSHH Regulation 9, every LEV system must have a thorough examination and test at least every 14 months, and some higher-risk processes need it more frequently. The examination checks airflow, capture velocity, filters and fan performance against the relevant exposure limits, and you must keep the records for at least five years. It should be carried out by a competent person, typically qualified to BOHS P601.
Phoenix Duct Clean · by the numbers
Phoenix examines and tests local exhaust ventilation to HSG258 and COSHH - measured, reported and certificated, UK-wide.