Monitoring the control of exposure to hazardous substances

Monitoring means measuring to show that control is adequate. It has nothing to do with the state of a worker's health.

When do you need to monitor?

Monitoring is appropriate:

when you need to show compliance with a WEL (Workplace Exposure Limit) 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.

Further information has details of organisations that can help with monitoring.