GB CLP Agency Opinions Reveal Targeted HSE Divergence From ECHA RAC on Hazard Classifications

GB CLP Agency Opinions indicate that the UK Health and Safety Executive has diverged from European Chemicals Agency Risk Assessment Committee positions in several recent classification decisions. The differences, identified in Agency Opinions covering substances such as 3,5-dimethylpyrazole, flazasulfuron, fosthiazate and penconazole, are relevant for professionals managing classification, labelling and regulatory compliance across Great Britain.

Examples of divergence in GB CLP Agency Opinions

A review of selected GB CLP Agency Opinions shows that HSE has taken a different view from ECHA RAC where it considers the underlying evidence to support an alternative hazard interpretation. For 3,5-dimethylpyrazole (CAS 67-51-6), the HSE Agency Opinion indicates the use of H360Fd for reproductive toxicity, rather than the H360FD wording adopted by RAC. This distinction reflects a difference in the strength of evidence for developmental toxicity. For flazasulfuron, HSE disagreed with RAC on the inclusion of muscle toxicity within specific target organ toxicity following repeated exposure (STOT RE), concluding that the available data did not support that element of the classification.

Reproductive toxicity and environmental classification differences

In the case of fosthiazate (CAS 98886-44-3), HSE classified the substance as Repr. 2 (H361fd) rather than Repr. 1B, citing uncertainties in developmental toxicity data. This represents a lower level of concern compared with the RAC position. For penconazole (CAS 66246-88-6), HSE assigned a chronic aquatic M-factor of 1, in contrast to RAC’s M=10, indicating a different interpretation of long-term environmental hazard.

Implications for compliance and regulatory strategy

These GB CLP Agency Opinions suggest that classification outcomes may not always align between Great Britain and the EU. For companies operating across both jurisdictions, this could require substance-level reviews to confirm whether classifications, labels and safety data sheets remain appropriate for each market. Differences in hazard statements or M-factors may influence how risks are communicated and assessed within supply chains. Regulatory teams may therefore need to monitor HSE Agency Opinions alongside EU developments and evaluate whether updates to documentation or internal hazard assessments are warranted. A practical step is to track the HSE GB mandatory classification and labelling publication table and compare Agency Opinions with corresponding EU harmonised classifications.