What are COSHH air monitoring requirements?

The COSHH (Control of Substances Hazardous to Health) Regulations 2002 require employers to protect workers from harmful substances. Air monitoring is part of this if employees could be exposed to hazardous substances in the air (like dust, vapours, gases, or fumes).

1. Exposure limits (WELs) might be approached or exceeded.
2. You're using a substance with serious health risks, like:
   • Carcinogens (e.g. silica dust, benzene)
   • Respiratory sensitizers (e.g. isocyanates)
3. You're relying on PPE or ventilation systems to control exposure.
4. You can’t be sure control measures are working without measurements.

• Risk assessment
• Control measures (e.g. ventilation, PPE)
• Health surveillance (if necessary)
• Training and information for staff