The design of extended one-generation reprotoxicity studies (EOGRTs) needs careful consideration, ECHA’s Member State Committee (MSC) concluded at its latest meeting. The EOGRTs test guideline describes three cohorts of F1 animals (reproductive/developmental endpoints which may be extended to include F2 generation; developing nervous system; developing immune system).

Following examination of four draft decisions on substance evaluation, the main message is that “the design of an extended one-generation toxicity test is very case specific”.

Several cases have been evaluated by the MSC, with conclusions of  i) it was not clear whether additional cohorts were needed, and that further range-finder studies were necessary; ii) mixed messages over whether EOGRTs was needed with extension to consider a second generation or whether the test could be waived on the basis of no significant exposure to workers or consumers; iii) disagreement over the inclusion of unnecessary cohorts, with data gaps in other areas identified.

The EOGRTs has the potential to be an all-encompassing study design which reduces animal use while maintaining or enhancing information for risk assessment. However not many laboratories are running the study due to its complexity, concerns are raised over the sensitivity of the one-generation test vs. the two-generation test and its regulatory acceptance is proving challenging to name but a few of the issues.

You can read a summary of the ECHA’s findings at: https://chemicalwatch.com/23700/reproductive-toxicity-tests-highly-specific-finds-echa-committee

For further information on the registration of plant protection products, biocides or general chemicals, or any other regulatory issues, please contact JSC on +44 (0)1423 520245, enquiries@jsci.co.uk