exposure testing

Every year, thousands of workers are made ill by exposure to dust in the workplace, this results in an increase of lung diseases such as asthma, COPD and cancer


Most industrial dusts contain particles of a wide range of sizes. The behaviour, deposition and fate of any particular particle after entry into the human respiratory system (and the body response that it elicits) depend on the nature and size of the particle. HSE distinguishes two size fractions for limit-setting purposes termed ‘inhalable’ and ‘respirable’.

Inhalable dust approximates to the fraction of airborne material that enters the nose and mouth during breathing, and is therefore available for deposition in the respiratory tract. Respirable dust approximates to the fraction that penetrates to the gas exchange region of the lung.

As an employer, you are responsible for taking effective measures to control exposure to hazardous substances and protect health.

ActionsActions and advice

The COSHH definition of a substance hazardous to health includes; dust of any kind when present at a concentration in air equal to or greater than 10 mg/m3 8-hour TWA of inhalable dust or 4 mg/m3 8-hour TWA of respirable dust.

This means that any dust will be subject to COSHH if people are exposed above these levels, however, some dusts have been assigned specific WELs and any exposure to these must therefore comply with the appropriate limit. Airborne dust may be generated from a wide range of work processes and scenarios, some of the more common are as follows:

  • Stone, cement and masonry dust (silica dust)
  • Wood dusts
  • Grain and flour dusts 
  • Cotton and wool process dust
  • General nuisance dust in the workplace

HelpHow can we help?

Our consultants are here to help you and can develop and implement monitoring strategies to identify if maximum exposure limits are being exceeded with respect to general dust or those dusts assigned with specific WEL's in the workplace.

Our team will advise on appropriate measures to be taken to reduce the risk of exposure and ensure you comply with the Control of Substances Hazardous to Health Regulations.


Knowledge Centre Article

Expand your knowledge on this topic by reading our informative article

Dust Exposure - The Complete Guide
Dust Exposure - The Complete Guide


Every year, thousands of workers are made ill from exposure to dust in the workplace that could result in an increase of lung diseases including Occupational Asthma, COPD and even Cancer.

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