On June the 7th was issued the pre-publication version of the EFSA–ECHA joint guidance on the identification of Endocrine Disruptors (EDs) in the context of the Regulations on Plant Protection Products (Reg. (EC) No 1107/2009) and on Biocidal Products (Reg. (EU) No 528/2012).

This guidance aims at the implementation of the “step by step” scientific criteria to identify EDs.

Even though the mode of actions (MoA) of the EDs are manifold this guidance is focused on estrogenic, androgenic, thyroidal and steroidogenic modes because currently there’s a better comprehension on how the modifications made by the substances are related to the adverse effects via EDs mode of actions.

Moreover for such modes, there are standardized in vitro and in vivo test guidelines widely shared on the evaluation of the effects on the tested parameters.

Different sets of criteria are applied to determine whether a substance is an ED for humans or for non-target organisms, the following criteria are common to both:
the substance shows an adverse effect as a change in the morphology, physiology, growth, development, reproduction, or, life span of an organism, system, or (sub)population that results in a damaging of functional capacity, an impairment of the capacity to compensate for additional stress, or an increase in susceptibility to other influences;

the substance alters the functions of the endocrine system so it has an endocrine activity;

the occurrence of an adverse effect as a result bound to that endocrine activity.

The subsequent separate criteria aim to specify the information to be included in the assessment for humans and non-target organisms respectively considering all the relevant scientific data available and applying the Weight of Evidence (WoE) approach to these data.

An extremely useful part of the guidance are the various appendices. Appendix A shows the additional considerations to make for thyroid disruption for humans, Appendix B illustrates the recommendations for the design, the conduction and the technical evaluation of hormonal studies. Appendix C lists the information requirements for the active substances, according to BPR and PPP regulations, which yield information on EDs. Appendix D presents different databases, softwares and models relevant for the identification of EDs, for the prediction of Endocrine activity. The latest 2 appendices are examples of research strategy and MoA for non-target organisms as fishes.