A monitoring survey is a formal detailed occupational hygiene evaluation to determine the degree of health hazard in a particular situation.

An occupational hygiene monitoring survey may involve professional judgement or quantitative measurements of the health hazards identified.

The results are often compared to good industry practice or recommended exposure limits.
Surveys can be carried out once during a specific task or repeated over an extended period to ensure that all exposure conditions are assessed.
Surveys are often used to demonstrate compliance with legal standards.
The selection of a suitable survey strategy is complex and requires considerable experience and skill to ensure that the survey will provide meaningful results.