Guidance on identifying endocrine disrupting effects


Recent revision of the European directive on plant protection products and new regulations concerning chemicals will allow the authorisation of a chemical product on the basis that they do not have endocrine disrupting properties. However there is no present agreed guidance on how to identify endocrine disrupting properties. Consequently, an ECETOC task force was formed to provide scientific based criteria that may be used within the context of the plant protection products directive and REACH.

The report created by the task force (Technical Report 106) reviews and summarises existing definitions of an endocrine disrupter as well as the test methods currently available to identify endocrine activity and/or toxicity. Specific scientific criteria for the determination of endocrine disrupting properties that integrate information from both regulatory (eco)toxicity studies and mechanistic/screening studies are proposed. These scientific criteria rely upon the nature of the adverse effects detected in regulatory (eco)toxicity study(ies) that give concern for endocrine toxicity and the description/understanding of the mode of action of toxicity which scientifically support and explain the adverse effects. The criteria developed are presented in the form of flow charts for assessing relevant effects for both human and environmental species. These charts are illustrated using example substances. In addition since all chemicals having endocrine disrupting properties may not represent the same hazard an element or assessment of potency is also proposed to discriminate chemicals of higher concern from those of lower concern.


The workshop was convened to introduce and discuss this guidance to conclude whether a chemical has or not endocrine disrupting properties.

Terms of reference

  1. Critically review all available definitions of endocrine disruption which apply to both human health and other organisms in the environment.

  2. Identify key and common themes from all definitions, as well as the relevance of these to chemical classification and risk assessment.

  3. Provide guidance on the nature and quality of data required to conclude the induction of endocrine disruption and causation of any adverse effects. This should include the ability to evaluate the potency of any endocrine disruption observed.

The workshop was an active event with a limited number of invited participants. The aim was to have a balanced participation of academia, regulators and industry in the discussions . The workshop began with presentations on the outcome of the above-mentioned task force which were followed by breakout group discussions and a final plenary session.


The findings of the workshop were published as Workshop Report 16 + Addendum