Air Monitoring

Under the Control Of Substances Hazardous to Health regulations (COSHH) it is essential to know what workplace exposure levels (WEL) the workforce is being exposed to.

When do you need to monitor?

Monitoring is appropriate:

  • when you need to show compliance with a (Workplace ExposureLimit) or BMGV ( Biological Monitoring Guidance Value)
  • when you need to show that control equipment or personal protective equipment is working well enough

Monitoring can also indicate the spread of contamination, eg surface wipes.

Screening, eg colorimetric detector tubes, meters, provides indicators of worker exposure only.

Personal air monitoring measures how much of a substance the worker inhales.

Biological monitoring measures how much of a substance has entered the body.

Air monitoring is extremely important in high risk activities such as asbestos, or worming in dust contaminated air such as a timber yard.

Guidance on ways to do the monitoring can be found in G409 at

For information on the levels and limits of exposures for all chemicals and associated products reference should be made to the EH40 document available at

To ensure that your air monitoring is working, and to comply with COSHH Regulations 2002 all businesses should consider having air monitoring measured by a competent person to identify what type(s) and levels of dusts, chemicals and solvents are present,  and use the results to consider improvements. Local exhaust ventilation systems (LEV’s) must be checked by a competent person every 14 months to ensure the ventilation system is working efficiently.

The combined air and ventilation checks will confirm WEL levels and if there is a need to introduce improved controls.

So if you own or are working in an industry that is using chemicals, timber, cement, cutting equipment etc, etc it is a legal requirement to have the LEV’s checked and to ensure you are not exceeding WEL limits.

Cal to action,

If you need  dust monitoring carried out or are seeking further information please call us on 01889 881887 or 07900 558547 email, or link up with us.