Biological Monitoring Guidance

Exposure Indices · Exposure Indices overview

Practical biological monitoring guidance for UK H&S managers commissioning a programme: how to choose substances, scope SEGs, brief a laboratory and interpret the report against HSE BMGVs and ACGIH BEIs.

Choosing substances to monitor

Substances with HSE BMGVs are the default. Add: substances with skin notation and significant dermal exposure; CMR substances where ALARP must be demonstrated; substances where a recent control change (process, RPE, LEV) needs verification.

Scoping SEGs

Define SEGs by task and substance, not job title. Each SEG should have at least six workers for routine verification; smaller SEGs are sampled exhaustively. Maintenance is usually a separate SEG because exposure profile differs sharply from production.

Briefing the laboratory

Brief should specify: substance and biomarker; matrix; timing; reporting units (per gram creatinine vs per litre); reference value to use; turnaround time; chain-of-custody requirements. Use a UKAS-accredited laboratory enrolled in an external proficiency scheme.

Reading the report

Look for: individual results plotted against the reference value; cohort geometric mean and 90th percentile; creatinine range and any samples excluded; analytical method, LOQ and measurement uncertainty; trend comparison if previous data exists.