SUMMARY HEALTH-BASED OBL* DERIVATION METHODS

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without a threshold effect

Method of derivation for substances with limited data

No BLV* derived. Yes, BLW* If negative feasibility assessment then no BEI* Recommendation of a BRV*

if no data? No value Where lack of data? Low level of confidence attributed

if no data? No value

pragmatic value and/or BRV* (2 options above)

Summary health-based OBL* derivation methods

Overall, four different methods were identified that can be used for the derivation of health-based Occupational Biomonitoring Levels (OBL*):

1. Derivation of health-based biomonitoring values directly based on the data on correlations between biomarker and health effects. 2. Derivation of biomonitoring values indirectly using established correlations between air and biomarker levels. 3. Use of PBK* modelling to derive biomarker levels from external intake 4. Use of simple approaches, like the urinary mass balance approach to calculate corresponding biomarker levels for POD*s (NOAELs* etc.), and applying assessment factors to account for the uncertainties.

These OBL* derivation methods are described and applied to selected case studies in the chapters 3.2 Derivation of OBL for human toxicity data rich substances, and in the chapter 3.3 Derivation of Provisional OBL for substances with limited human toxicity datasets. A general tiered approach for derivation of health and non-health based OBLs* is provided in chapter 5.

OCCUPATIONAL BIOMONITORING GUIDANCE DOCUMENT © OECD 2022