Workplace Exposure Monitoring & COSHH Air Sampling
UKAS-accredited personal and static dust sampling for COSHH compliance. IOM-head inhalable and cyclone respirable methods, analysed at a UKAS-accredited laboratory. Chartered consultants, UK-wide.
COSHH air monitoring done properly
Under Regulation 10 of the Control of Substances Hazardous to Health Regulations 2002, an employer must measure exposure to hazardous substances whenever it is needed to demonstrate that a Workplace Exposure Limit (WEL) is not being exceeded, or for any process listed in Schedule 5. In practice that covers almost every workplace where wood, flour, grain, cement, stone, metal, paper or fume is generated — from joinery shops and bakeries to foundries, quarries and ceramic factories.
Air Dust Odour is run by Malcolm Pounder CEnv MIAQM, a Chartered Environmentalist with two decades of hands-on air-quality experience. We carry out personal breathing-zone sampling and fixed static monitoring across the UK, send filters to the Institute of Occupational Medicine (IOM) — our default UKAS-accredited laboratory — and deliver clear, defensible reports that compare each result to the relevant WEL in HSE document EH40 and recommend proportionate, achievable controls.
We focus on the dusts we know best: inhalable dusts sampled with the IOM head (wood, flour, grain, soft paper, general inhalable, metal dust) and respirable dusts sampled with a cyclone (respirable crystalline silica, respirable Portland cement, general respirable). If you need an honest, hands-on survey rather than a tick-box exercise, that is exactly what we deliver.
Dusts and Fumes We Routinely Sample
Every substance below has a specific HSE method (MDHS) and a Workplace Exposure Limit published in EH40. We use the right sampling head for each one and the appropriate UKAS-accredited analysis.
Wood Dust Monitoring
Hardwood and softwood dust sampled with the IOM head per MDHS 14/4, gravimetrically analysed. The WEL is 3 mg/m³ (8-hr TWA) for hardwood and softwood — one of the lowest dust limits in EH40, and frequently breached in joineries, sawmills, kitchen-fitter workshops, MDF cutting bays and construction site carpentry.
Flour Dust Monitoring
Inhalable flour dust sampled with the IOM head, WEL 10 mg/m³ (8-hr TWA) with a 30 mg/m³ short-term limit. Critical in bakeries, flour mills, pizza kitchens, pasta makers and bakery ingredient packers — flour dust is one of the leading causes of occupational asthma in the UK.
Grain Dust Monitoring
Inhalable grain dust per MDHS 14/4 with the IOM head, WEL 10 mg/m³ (8-hr TWA). Essential for grain stores, animal-feed mills, agricultural co-operatives, malt houses, ports handling grain and farms with on-site driers. Grain dust carries endotoxin and is a recognised cause of farmers' lung.
General Inhalable Dust (10 mg/m³)
For mixed or unidentified dusts where no substance-specific WEL applies, the general inhalable WEL of 10 mg/m³ (8-hr TWA) is the relevant benchmark. We sample with the IOM head per MDHS 14/4 and screen for the major constituents if the result is close to the limit.
General Respirable Dust (4 mg/m³)
The general respirable WEL of 4 mg/m³ (8-hr TWA) applies to mixed respirable dusts. We sample using a Higgins-Dewell or similar cyclone at the calibrated flow rate per MDHS 14/4, suitable for stone-cutting, concrete-grinding, ceramic and cement-handling environments.
Respirable Crystalline Silica (RCS)
Respirable crystalline silica sampled with a cyclone per MDHS 101 and analysed by X-ray diffraction at a UKAS-accredited laboratory. The WEL is just 0.1 mg/m³ (8-hr TWA) — routinely exceeded in stonemasonry, kitchen-worktop fabrication (engineered quartz), quarrying, concrete cutting and brick handling. Increasingly the subject of HSE proactive inspections.
Cement & Construction Dust
Portland cement (inhalable WEL 10 mg/m³, respirable WEL 4 mg/m³) sampled with the appropriate head, plus mixed construction dusts. Relevant for batching plants, precast factories, dry-bagging operations and demolition contractors.
Metal Dust & Welding Fume
Inhalable metal dust sampled with the IOM head and analysed by ICP-MS for the metals of concern (nickel, chromium, manganese, cobalt, beryllium, lead). Following the HSE 2019 reclassification of mild-steel welding fume as a carcinogen, fume control and assessment is now expected for all indoor welding operations regardless of duration.
Gas & Vapour Monitoring (CO, CO&sub2;, VOCs)
Direct-reading multi-gas monitoring using calibrated electrochemical, NDIR and PID sensors. Carbon monoxide (30 ppm WEL), carbon dioxide (5,000 ppm WEL), total VOCs as toluene, hydrogen sulphide, nitrogen dioxide, oxygen depletion and LEL. For boiler rooms, plant rooms, indoor air quality assessments, BREEAM Hea 02, confined space, underground car parks and construction site fixed monitoring.
How a Typical Survey Runs
Every survey follows HSE methodology and BS EN 689 sampling-strategy guidance. Here is the standard workflow from first call to signed-off report.
A consultancy, not a sample factory
Frequently Asked Questions
What is workplace exposure monitoring?
Workplace exposure monitoring is the measurement of airborne substances that workers breathe in during normal work activities. Personal sampling pumps draw a known volume of air through a filter or sampling head worn in the worker's breathing zone. The filter is then analysed by a UKAS-accredited laboratory and the result compared to the relevant Workplace Exposure Limit (WEL) published in HSE document EH40. It is the standard way to demonstrate compliance with Regulation 10 of the Control of Substances Hazardous to Health (COSHH) Regulations 2002.
What is an IOM sampling head?
The IOM (Institute of Occupational Medicine) sampling head is the UK industry standard device for collecting the inhalable fraction of airborne dust on a worker's lapel. It uses a 15 mm circular inlet and a pre-weighed internal filter cassette, sampled at 2.0 L/min, and matches the inhalable convention published in BS EN 481. Inhalable dust includes all particles a worker can breathe in through nose or mouth (up to about 100 micrometres aerodynamic diameter) and is the correct fraction for assessing wood dust, flour dust, grain dust, soft paper dust, most metals and the general inhalable dust WEL of 10 mg/m³.
What is the difference between inhalable and respirable dust?
Inhalable dust is the fraction that enters the nose and mouth — typically sampled with an IOM head and used to assess wood dust, flour dust, grain dust and many other substances with an inhalable WEL. Respirable dust is the finer fraction (50% cut at 4 µm aerodynamic diameter) that penetrates deep into the alveolar region of the lungs — sampled using a cyclone such as the Higgins-Dewell, and used to assess respirable crystalline silica, respirable Portland cement and the general respirable dust WEL of 4 mg/m³. The correct sampling head for each substance is set out in the HSE MDHS series.
How often do I need to monitor workplace exposure?
Under COSHH Regulation 10, monitoring is required where it is needed to ensure a Workplace Exposure Limit is not exceeded or for any process specified in Schedule 5 (such as vinyl chloride manufacture, electrolytic chromium and certain spray-paint operations). In practice, most dust-generating workplaces should carry out baseline monitoring whenever processes change or new substances are introduced, with re-monitoring every 12 months or sooner if exposure has been close to a WEL or if controls have been altered.
How much does workplace exposure monitoring cost?
A typical full-shift visit for personal sampling of around 4 to 8 workers, including report writing, starts from around £750 to £1,200 plus VAT. UKAS lab analysis is charged separately, typically £35 to £85 per sample depending on the analyte. Larger surveys with more workers, multiple substances or static area monitoring scale up from there. See our cost breakdown page for worked examples.