Lead Biological Monitoring

Heavy Metals · Heavy Metals overview

Lead biological monitoring is statutory under the Control of Lead at Work Regulations 2002 (CLAW). Blood-lead is measured at defined intervals against published action and suspension levels.

CLAW action and suspension levels

Women of reproductive capacity: action level 25 µg/dl, suspension level 30 µg/dl. Young persons: action 40 µg/dl, suspension 50 µg/dl. Other workers: action 50 µg/dl, suspension 60 µg/dl. Sampling frequency depends on exposure category as defined in CLAW Schedule 2.

Sampling and analysis

Whole blood is collected into K2 EDTA tubes by a competent phlebotomist (typically the appointed occupational physician). Analysis is by graphite furnace AAS or ICP-MS at a UKAS-accredited laboratory.

Biological effect monitoring

Zinc protoporphyrin (ZPP) or free erythrocyte protoporphyrin (FEP) measurement is sometimes used alongside blood-lead as an indicator of haem-synthesis inhibition. ZPP reflects exposure over the preceding 90 days.