In summer 2013, when an initial draft of criteria for the identification of endocrine disrupters (EDs) was discussed within the European Commission (the executive of the European Union), a group of toxicology journal editors published severe scientific concerns about the proposed approaches (Dietrich et al. 2013). As a result, a controversy about the toxicological principles that should guide the identification of endocrine-disrupting chemicals flared up in the scientific press among toxicologists and endocrinologists (Bergman et al. 2013; Zoeller et al. 2014; Autrup et al. 2015). The realization that this dispute had contributed to a degree of misunderstanding among decision-makers in the European Commission motivated a group of those involved in the debates to explore whether it might be possible to bridge the differing views and come to a common understanding. In this brief communication, we describe the political and regulatory context that has led to this debate, and present the consensus that has been reached among scientists who took opposing views in the previous dispute, during a two-day workshop held in Berlin, Germany, 11–12 April 2016, hosted by the German Federal Institute for Risk Assessment (BfR).
In line with established practice in other jurisdictions, the risk management of chemicals in the EU is generally based on risk characterization. However, for some toxicological effects, the EU has introduced hazard-based regulations. This applies especially to chemicals used as active substances in plant protection products and biocidal products. According to provisions in several pieces of EU law for plant protection products and biocidal products, the European Commission was obliged to develop scientific criteria for the identification of EDs by 2013, but to date (April 2016), has failed to do so.
Motivated by concerns about health effects caused by the delay in developing criteria for endocrine-disrupting substances, Sweden (a member state of the EU) brought a court case against the European Commission in 2014. Finally, in winter 2015, the General Court of the EU ruled that the Commission had breached EU law, by failing to adopt measures concerning the specification of scientific criteria for the identification of endocrine-disrupting substances. The Court further noted that the Commission’s defense that the scientific criteria which it had proposed were the subject of criticism, in summer 2013, was irrelevant to the fact that the Commission had an obligation to present these criteria according to the deadlines enshrined in EU law (December 2013) (General Court of the EU 2015).
The apparent controversy among scientists centered on disagreements about the most appropriate approach to assess endocrine disruptors, and was focused on the scientific assumptions that could be made during the identification of a chemical as an endocrine disruptor. Prominent in these disputes was the question of the existence of thresholds for endocrine disruptors and of the significance of non-monotonic dose–response relationships, which has a significant impact on the way risk assessments are conducted for these chemicals (Dietrich et al. 2013; Bergman et al. 2013).
However, at the Berlin workshop, the protagonists of the scientific controversy were able to agree that the requirement for scientific criteria for the identification of endocrine disruptors per se, can be interpreted as an issue of hazard identification. This enabled the workshop participants to conclude that differences in opinion regarding the existence of thresholds and non-monotonic dose–response curves, although relevant to the risk characterization of EDs, are not a hindrance for defining scientific criteria for their identification. The consensus that was reached on scientific principles for the identification of endocrine-disrupting chemicals is offered as advice to the European Commission for the first step in their decision-making process to meet their legal obligations.