What is an endocrine disruptor (ED)?

An endocrine disruptor is an exogenous substance or mixture that alters hormone functions and consequently causes adverse health effects in the organism exposed or its progeny and in subsequent generations (according to the internationally agreed WHO definition in 2002). Environmental effects of EDs can be observed for one (sub)population.

Hormones are part of the endocrine system and play a key role in many biological and physiological functions. They can cause effects at very low levels and at particular points in time. A disruption of the endocrine system, especially at some development stages such as the foetal development of genitalia, can have irreversible consequences. Effects may show up immediately or only several years later (after the so-called latency period). Exposure to EDs is, for instance, associated with infertility, immune system disorders, reproductive abnormalities (e.g. cryptorchidism and hypospadias in boys), early breast development in girls, testicular and other cancers, obesity and diabetes.

On 3 July 2013 the Belgian Superior Health Council (SHC) issued an opinion on endocrine disruptors, low-dose effects, critical windows of sensitivity…

Information report of the Senate

On March 23, 2018, the Senate adopted in plenary an Information Report on endocrine disruptors in Belgium. This report recommends the development of a national action plan on endocrine disruptors, in consultation with scientists, companies and civil society.

72 specific recommendations are listed for the prevention and elimination of endocrine disruptors in consumer products. These recommendations will guide the different actions to be taken against endocrine disruptors.

Pregnant women:

Women who wish a child and pregnant women are strongly advised to limit exposure to EDs as much as possible. Indeed, endocrine disruptors can affect the foetal growth and development, even at very low levels. 

You can find practical information about reducing exposure to EDs in many publications:

How can EDs be identified?

For a substance to be recognised as an endocrine disruptor, it should meet three essential conditions:

  1. Evidence for an endocrine mechanism, determined e.g. by means of in vitro testing on cells
  2. Evidence for one or more adverse effects in an intact organism (animal testing)
  3. A plausible causal relationship between the two

Together with the relevant European agencies and the other EU Member States, the Belgian Federal Public Service of Health is involved in developing identification criteria and in assessing potential endocrine disrupting substances.

Different testing methods exist to identify substances as endocrine disruptors. For the purpose of common interpretation, the Organisation for Economic Co-operation and Development (OECD) has produced a guidance document on standardized tests currently available and the use thereof (guidance document No 150).

Substances already identified as endocrine disruptors

Substances identified by the competent authorities as being endocrine disruptive are listed as candidates for authorisation. They are then recognised as being substances of very high concern (SVHC) as they present an equivalent level of concern to carcinogenic, mutagenic and reprotoxic substances and to PBTs (persistent, bioaccumulative and toxic substances) or vPvBs (very persistent and very bioaccumulative substances).

Here are some substances among those already identified as being endocrine disruptors and some use examples:

  • 4-nonylphenol: used in the manufacturing of epoxy resins and stabilizers in plastics, paints, etc.
  • 4-nonylphenol ethoxylates: used in the manufacturing of polymers, paper, textiles, paints, etc.
  • 4-tert-octylphenol: used as an intermediate in the production of resins, paints, etc.
  • 4-tert-octylphenol ethoxylates: detergent used in cell and molecular biology as a cell membrane disruptor (Triton X-100), surfactant in soaps, etc.
  • Bis(2-ethylhexyl) phthalate (DEHP): used to soften PVC plastics and in other plastic compounds, also used in some paints, printing inks, etc.
  • Bisphenol A: used in receipts (this use will be banned from 2 January 2020), in the manufacture of polycarbonate plastics, etc. 

The identification as endocrine disruptor is a first step before taking regulatory action to reduce exposure (e.g. restriction, authorisation).

Several EU laws apply:

Biocidal Products Regulation (528/2012) and Plant Protection Products Regulation (1107/2009)

In December 2013 the European Commission (EC) should have provided a proposal or adopted a legislative act regarding identification criteria for plant protection products and biocidal products respectively.

In January 2015 Sweden, backed by the European Parliament and the Council of the European Union, brought an action before the European Court of Justice (ECJ) as the EC had still not adopted the identification criteria as provided for in the BPR. In December 2015 the ECJ ruled in favour of Sweden, holding that the Commission's obligation is clear, precise and unconditional.

In June 2016, the Commission presented a first proposal of ED identification criteria for both legislations. The respective adoption procedures were followed.

The biocidal products ED criteria  are published and they apply since 7 June 2018. The plant protection products ED criteria  are also published and will apply from 10 November 2018.
guidance document to assist companies and authorities in applying the ED identification criteria is available on the ECHA website.

REACH Regulation (1907/2006)

A substance can be identified as an endocrine disruptor on a case-by-case basis under the REACH Regulation (identification of substances of very high concern as part of the authorisation process).

The identification of endocrine disruptors under REACH is part of a European "SVHC Roadmap to 2020". This roadmap provides for the identification of all relevant substances of very high concern (SVHC) by 2020. Endocrine disruptors belong to that group of substances.

An Endocrine Disruptor Expert Group made up of experts from the various EU Member States has been established within the European Chemicals Agency (ECHA) in order to contribute to that objective.

Other REACH processes, such as the substance evaluation process, help identify endocrine disrupting substances. If an EU Member State suspects a substance to be endocrine disruptive, additional information or testing can be requested through that process. 

Other tools and documents:

  • WHO (Educational material available for the health sector)
  • WECF

European Commission: