Endocrine active substances are chemicals that can interact or interfere with normal hormonal activity; when this leads to adverse effects they are called endocrine disruptors. Following a request in 2012 from the European Commission, EFSA’s Scientific Committee has developed an opinion that clarifies the scientific criteria for identifying an endocrine disruptor. EFSA endorses the World Health Organization’s definition of an endocrine disruptor and highlights that not all endocrine active substances are endocrine disruptors. This depends on whether there is reasonable evidence that the substance can cause an adverse effect as a result of its interaction or interference with the endocrine system.
EFSA’s experts concluded that available or soon to be available internationally agreed testing methods can identify interference of chemical substances with four important endocrine pathways in mammals and fish known to be sensitive to endocrine disruption. EFSA’s opinion makes recommendations for future activities, including testing methods and testing strategies. EFSA concludes that a risk assessment approach which considers both potential adverse effects of endocrine active substances together with the likelihood of exposure makes best use of available information to regulate their use. EFSA’s scientific advice will help inform the decisions of EU risk managers to protect consumers and the environment from possible risks associated with endocrine disruptors in the food chain.
EFSA’s Director of Science Strategy and Coordination, Hubert Deluyker stated: “EFSA is aware that national, European and international organisations have done state of science reviews looking at the possible health effects of endocrine active substances. EFSA’s opinion complements this work. The Authority has reviewed the currently available testing methods to assist risk managers in defining what may or may not be an endocrine disruptor using science-based criteria. Our opinion also underlines the need for further testing strategies to be developed to test these substances in a systematic and transparent way.”
Regarding EFSA’s review of current test methods, the Chair of EFSA’s Scientific Committee Prof. Tony Hardy commented: “This was an important part of our work and it contributes to EU and international discussions in this area. We concluded that current tests generally are adequate for mammals, fish and to a lesser extent also for birds and amphibians and cover four important endocrine pathways. However no single test is sufficient to decide whether a substance is an endocrine disruptor and several tests need to be done and then assessed together by experts in a weight-of-evidence approach.”
EFSA’s opinion also briefly discusses several issues related to the testing of chemicals which are not unique to endocrine disruption: these include ‘windows of susceptibility’ (critical periods of development such as conception, pregnancy, infancy, childhood and puberty, when the body may be more sensitive to chemicals possibly increasing the likelihood of harmful effects in the short-term or later in life); and other matters related to chemical toxicology which are the subject of on-going scientific debate, such as low dose effects, non-monotonic (e.g. U-shaped) dose-response curves and exposures to multiple chemical substances. The Authority recommends as a follow-up activity to this opinion further work to clarify in a broader context how these various aspects could impact on current risk assessment approaches and testing strategies for any chemical substance.
Whereas EFSA’s work on this topic is concerned chiefly with endocrine active substances related to the food chain (for example, pesticides), its contribution forms part of a wider initiative co-ordinated by the European Commission and is intended to support and inform EU decision-makers’ updating of current legislation in a variety of areas (chemicals, pesticides, biocides). The Directorate General for Health and Consumers requested scientific advice on endocrine disruptors in order to prepare criteria for plant protection products by the end of 2013. To ensure consistency, other EU scientific advisory bodies involved in this process supported the development of EFSA’s opinion: the European Medicines Agency, the European Chemicals Agency, the European Environment Agency, and the Joint Research Centre.
- Scientific Opinion on the hazard assessment of endocrine disruptors: Scientific criteria for identification of endocrine disruptors and appropriateness of existing test methods for assessing effects mediated by these substances on human health and the environment
- Frequently Asked Questions on endocrine active substances
EFSA has organised a scientific meeting today in Brussels to inform a wide range of stakeholders about the Authority’s work and the work of its European and international partners in the area of endocrine active substances and endocrine disruptors.
 Several of these are detailed in the appendices of EFSA’s opinion, including: Global Assessment of the State-of-the-Science of Endocrine Disruptors (WHO/IPCS, 2002), State of the Art of the Assessment of Endocrine Disruptors (European Commission/Kortenkamp et al., 2011), Endocrine disrupters and child health: Possible developmental early effects of endocrine disrupters on child health (WHO, 2012), State of the Science of Endocrine Disrupting Chemicals (UNEP/WHO, 2013).
 Non-monotonic dose-response curves are produced when response to a substance increases with the dose at some points and decreases as the dose increases at others.