The dangers of omitting exposure assessment from REACH submissions
April 28th, 2013
Many registrants have made the interpretation that in REACH, if a registered substance is not classified on the basis of available data, then exposure assessment and risk characterisation are not required (even at high tonnage). In our opinion, this position is not often a robust one in terms of reliable chemical safety assessment. This is because:
- It is rare for the higher Annex data requirements to be fully complete, and where any data waiving arguments citing low or negligible exposure are used, then quantified exposure assessment is vital.
- Classification criteria under CLP often use threshold values, meaning that it is not unusual for a substance which does not require classification (as the hazard criteria are not met), to have the potential to cause effects at higher doses / concentrations. Relevant safe levels (DNELs and PNECs) can be defined without difficulty in such cases, and ECHA may well wish to see RCR values.
- If no effects at the maximum achievable dose has already been demonstrated, DNEL / PNEC values cannot be quantified, but even then a qualitative assessment of risk can be made (in new testing programmes, welfare must be considered when setting dose levels).
Exposure assessment of a substance can certainly be a challenging project in some cases, but the various tools available to conduct an exposure assessment for human health and the environment are well-suited to most chemical types. Recent upgrades to the CHESAR tool have improved its integration with IUCLID and CSR generation, and convenience.
In our experience, if a regulator perceives a major deficiency (such as no assessment of exposure or risk in place at all) they are then more likely to impose requirements of significant (and costly) additional work. But if an adequate exposure assessment is in place, a stepwise and focussed refinement program may be defensible, should an Evaluation letter be received.