The European legislation on plant protection products (Regulation (EC) No. 1107/2009) sets out strict criteria for approval of active substances and includes the assessment of endocrine disrupting properties. Active substances that are endocrine disruptors will not be approved under the regulation unless there is negligible exposure to humans and non-target species. In addition to this, endocrine disrupting substances approved because of negligible exposure will become candidates for substitution with less hazardous substances during the authorisation stage at Member State level. The burden of proof is placed on the notifier.

To date wca has aided its clients in the evaluation of over 40 active substances for the identification of potential endocrine disrupting properties by conducting Weight of Evidence reviews of the available studies.

The weight of evidence evaluations are based on a framework consisting of the following evaluation steps:

1) Systematic review – identification of all relevant studies in a transparent and robust manner,

2) Study reliability – assessment of the quality and reliability of studies,

3) Study relevance – evaluation of endpoint relevance to the determination of mechanism and adverse effect, and

4) Balance of the weight of evidence – determination of the consistency in the available evidence and the biological plausibility of a link between adverse effects and an endocrine mode of action.

The reports generated concluded with advice on whether the available data would result in the determination of a substance as an endocrine disrupter, identified data gaps (where these were present), and provided recommendations on what actions were required.