Towards an enhanced role for human biomonitoring in REACH regulation: Current landscape and future prospects

Human biomonitoring (HBM) plays a critical role in assessing human exposure to chemicals and their potential health impacts. The REACH (Registration, Evaluation, Authorisation, and Restriction of Chemicals) Regulation aims to protect both the general population and workers from the risks posed by chemicals. HBM provides valuable data to support risk assessment and regulatory decisions on chemicals and chemical's use. However, despite the acknowledged potential, the current REACH guidance provides only limited and non-binding recommendations for the use of HBM in regulatory processes. Therefore, the systematic integration of HBM into the REACH regulatory framework remains limited. Several key factors contribute to this limitation: an over-reliance on traditional exposure modelling in risk assessment, the absence of enforcement mechanisms for its application by registrants and regulators and the lack of harmonized biomonitoring limit values, even though standardized approaches for deriving biomarker-based no-effect level (DNEL_biomarker) are available. Additional barriers include restricted data availability, as HBM data are classified as medical information and subject to strict data protection regulations. REACH will benefit from a more systematic use of HBM data. Several solutions and calls for action are presented here to advance the use of HBM in REACH regulations.