Phoenix Journal · LEV Testing
Fine wood dust is one of the most quietly dangerous substances in any joinery or workshop, and its strongest link is to a rare cancer of the nose and sinuses. Here is how that link works, and what good extraction and LEV testing do to break it.
Wood dust looks harmless. It settles on benches and rafters, it smells clean, and most people who work with it spend years assuming the worst it can do is make them sneeze. The reality is harder to see, because the damage that matters most happens deep in the nose and sinuses, slowly, and often decades after the exposure that caused it.
The link between wood dust and nasal cancer is not a fringe theory or a precaution taken just in case. It is one of the best established occupational cancer links there is, backed by decades of evidence and recognised by the bodies that set workplace health standards in the UK and worldwide. If your business cuts, sands, routs or sweeps up timber - a kitchen fit-out joinery, a bespoke furniture shop, a maintenance workshop attached to a larger site - this is a risk you carry, whether or not anyone has ever named it out loud.
This page explains how the harm actually happens, what the numbers say, and why the extraction system that captures the dust is only as trustworthy as the last time it was properly tested.
The evidence in plain terms
The International Agency for Research on Cancer - the World Health Organisation body that grades cancer-causing substances - placed wood dust in Group 1 back in 1995. Group 1 is the strongest classification it awards, the same tier as asbestos and tobacco smoke, and it means the evidence for cancer in humans is considered conclusive rather than merely suspected. The specific disease most closely tied to wood dust is sinonasal adenocarcinoma: a cancer of the lining of the nasal cavity and the paranasal sinuses, the air-filled spaces in the bones around your nose. It is rare in the general population, but among long-term woodworkers the risk rises many times over.
Hardwoods such as oak, beech and mahogany carry the clearest link, which is why UK law treats them more strictly than softwoods. Under the Control of Substances Hazardous to Health Regulations 2002 - COSHH, as everyone calls it - the workplace exposure limit for hardwood dust is 3 mg/m³ averaged over an eight-hour day. That limit was tightened from 5 mg/m³ in January 2020, a change that tells you which way the science has been pointing. Softwood dust sits at 5 mg/m³, and where the two are mixed, the stricter hardwood figure of 3 mg/m³ applies to the whole lot.
What is happening inside the nose
To understand why wood dust settles on the nose in particular, it helps to picture where the dust goes when you breathe it. The larger, heavier particles thrown off by sawing and sanding do not travel far down into the lungs. Instead they deposit high up, in the narrow, twisting passages of the nasal cavity and the sinuses, where the airflow slows and the tissue is moist. That tissue was never designed to filter a constant load of fine timber particles, and over time the lining reacts.
The reaction is chronic irritation. The delicate cells that line the nose become inflamed, then start to change their character in an attempt to cope - a process pathologists call metaplasia, where one cell type is gradually replaced by a tougher one. Push that process on for long enough, decade after decade, and some of those cells can slip further, into dysplasia and eventually into cancer. It is a slow-motion injury, which is exactly what makes it so easy to underestimate. Nobody feels a tumour forming. The warning signs, when they come, are mild and easily dismissed: a blocked nostril that never quite clears, occasional nosebleeds, a reduced sense of smell, a persistent runny nose on one side.
The timescale is the cruel part. The latency between meaningful exposure and a diagnosis is estimated at twenty years or more. That means the joiner who develops sinonasal cancer in their sixties may be paying for dust they breathed in their thirties, in a workshop that has long since changed hands or closed. It also means you cannot judge whether your dust control is working by asking whether anyone has fallen ill yet. By the time illness appears, the exposure that caused it is ancient history. The only honest measure is the dust in the air today, and whether it is being captured before anyone breathes it. If you want a fuller picture of just how easy this hazard is to wave away on a busy shop floor, our guide on why wood dust is the workshop hazard that is easy to underestimate is worth reading alongside this one.
Cancer is not the only harm, either. The same dust drives occupational asthma, dermatitis, and a steady loss of lung capacity. Sinonasal cancer is simply the most serious and the most specific outcome - the one that puts wood dust in the same regulatory bracket as the substances everyone already fears.
Controlling the dust, and proving it
Because the disease is invisible for so long, the whole weight of prevention falls on stopping the dust reaching the air people breathe. COSHH does not simply ask you to stay under the exposure limit. It asks you to reduce exposure to as low a level as is reasonably practicable - the ALARP principle - regardless of where the legal number sits. In practice, for cutting and sanding timber, that means local exhaust ventilation: extraction hoods, ducting and a filter unit that draw dust away at the point it is created, before it can drift up into the breathing zone or settle on surfaces to be disturbed again later.
The catch is that extraction quietly decays. Ducting clogs, filters blind over, fans lose pull, dampers stick, and a hood that captured beautifully on the day it was installed can be moving a fraction of the air it should a couple of years on - with nothing visible to show for it. This is why COSHH requires local exhaust ventilation to undergo a thorough examination and test, carried out by a competent person, at least every fourteen months. For a high-risk dust like hardwood, many systems warrant testing far more often than that outer limit. A proper examination measures the airflow, the pressure drops across the system and the condition of the filtration, then judges it against how the system was designed to perform - not simply whether it switches on. Competency here is usually demonstrated through the BOHS P601 qualification and the methods set out in the HSE's guidance document HSG258.
The point of all this is straightforward. You cannot see sinonasal cancer coming, and you cannot see whether your extraction is still winning the battle against the dust. A thorough examination turns an invisible question into a measured, documented answer - and gives you a record you can stand behind if your control of a Group 1 carcinogen is ever questioned.
Questions
The clearest cancer evidence relates to hardwoods such as oak and beech, which is why UK law sets a stricter exposure limit of 3 mg/m³ for hardwood dust against 5 mg/m³ for softwood. That does not make softwood dust harmless - it still causes asthma, irritation and other respiratory harm. Where hardwood and softwood dust are mixed, the tighter 3 mg/m³ limit applies to all of it.
The latency is typically estimated at twenty years or more, so a diagnosis today can trace back to dust breathed decades earlier. This long delay is precisely why the absence of illness among your current staff tells you nothing about whether your dust control is adequate. The only reliable measure is the dust level in the air now, kept as low as reasonably practicable.
Not on its own. COSHH requires that local exhaust ventilation is kept in effective working order and undergoes a thorough examination and test by a competent person at least every fourteen months, and often more frequently for a high-risk dust like hardwood. Extraction quietly loses performance as ducts clog and filters blind, so a system that is switched on is not necessarily a system that is working. The test provides the documented proof that it still is.
Phoenix Duct Clean · by the numbers
Phoenix examines and tests local exhaust ventilation to HSG258 and COSHH - measured, reported and certificated, UK-wide.