Endocrine disruptors
Endocrine disruptors are chemicals that interfere with hormones and may cause harmful effects in humans and wildlife.
Hormones are produced and regulated by the endocrine system, a network of organs and glands such as the thyroid.
Hormones are essential for our growth, development, reproduction, metabolismThe total sum of physical and chemical processes that occur within living organisms and many other bodily functions.
Endocrine active substances can imitate or block natural hormones, change hormone levels or affect how hormones are made, transported or broken down in the body.
Interacting with the endocrine system does not automatically mean a substance is harmful.
Humans and animals have natural mechanisms that help keep hormone levels balanced.
In this way our bodies compensate for some hormonal disturbances before harmful effects occur.
Scientists distinguish between endocrine-active substances, which can interact with hormones, and endocrine disruptors, which cause harmful health effects through that interaction.
What's the difference?
Endocrine-active substance
Interacts with the hormone system.
Endocrine disruptorA substance that adversely affects the endocrine (hormone) system leading to negative effects for organisms and/or their offspring
Interacts with the hormone system and causes a harmful effect.
People and animals can encounter these substances through food and other sources such as drinking water, cosmetics and household products.
Some endocrine-active substances occur naturally. Examples include plant compounds known as phytoestrogens, which are found in foods such as soya and flaxseed.
Others are man-made. Examples include environmental pollutants such as dioxins and polychlorinated biphenyls (PCBs), and some pesticides.
Some medicines are specifically designed to act on the endocrine system.
For example, birth control pills work by affecting hormones, while some medicines replace thyroid hormones, which help regulate how the body uses energy and how it grows and develops.
Scientists study endocrine disruptors because exposureConcentration or amount of a particular substance that is taken in by an individual, population or ecosystem in a specific frequency over a certain amount of time to them can increase the likelihood of harmful health effects, either shortly after being exposed to them, later in life or, in certain cases, in subsequent generations.
Milestones
2026
March
EFSA publishes an external scientific report on the development of an adverse outcome pathwayA method of visualising a chain of events linked by causality that may lead to a harmful outcome for organisms or the environment network for reproductive toxicityThe potential of a substance to cause harm to a living organism endpoints to support identification of endocrine disrupters.
2025
December
EFSA publishes a statement clarifying the use of new methods and the interpretation of changes in thyroid histology in assessments for potential thyroid-mediated endocrine disruption in amphibians.
November
EFSA publishes a technical report on the outcome of the pesticides peer review meeting on general recurring issues in mammalian toxicology and ecotoxicologyThe study of the adverse impacts of substances, particularly chemicals, in relation to the environment and public health related to endocrine disruptors.
2023
EFSA publishes a scientific opinion on the development of adverse outcome pathways relevant for uterine adenocarcinoma.
2021
EFSA publishes an Annex to the guidance on how to use a newly available test methods (NAM) on amphibians in the testing strategy: Use of the XETA in the assessment strategy of the ECHA/EFSA guidance.
2020
EFSA publishes a technical report on the outcome of the pesticides peer review meeting on general recurring issues in mammalian toxicology related, among others, to endocrine disruptors
EFSA establishes a working group on endocrine disruptors to support the assessment of endocrine disrupting properties of pesticideSubstance used to kill or control pests, including disease-carrying organisms and undesirable insects, animals and plants active substances on humans and non-target organismsA plant, animal or insect that a pesticide is not meant to affect, but could be impacted..
2018
Scientific criteria to determine endocrine disrupting properties in plant protection products and biocidal products become applicable.
EFSA and the European Chemicals Agency (ECHA) publish guidance on how to identify substances with endocrine disrupting properties in pesticides and biocides.
2017
EFSA and ECHA launch a public consultation on their draft guidance on how to identify substances with endocrine disrupting properties in pesticides and biocides.
2016
EFSA and ECHA publish an outline of the guidance they are developing on how to identify substances with endocrine disrupting properties in pesticides and biocides.
2014
The European Commission launches an online consultation to help define criteria for endocrine disruptors in pesticides and biocides.
2013
EFSA’s Scientific Committee publishes a scientific opinion on the hazardA substance or activity which has the potential to cause adverse effects to living organisms or environments assessment of endocrine disruptors.
2012
The European Commission asks EFSA, the Commission Scientific Committees, EMA and ECHA for scientific advice on the assessment and testing of endocrine active substances.
2010
EFSA’s Scientific Committee establishes an Endocrine Active Substances Task Force, with the support of EFSA’s Advisory Forum of national competent authorities, to clarify the state-of-play on endocrine active substances and to provide recommendations.
EFSA's role
Our scientists assess possible harm from substances in food and the environment and consider endocrine-related effects on humans and/or animals wherever relevant.
For pesticides, we determine whether an active substance meets the scientific criteria for being identified as an endocrine disruptor.
Our pesticide assessments also consider endocrine-disrupting effects on wildlife, focusing primarily on mammals, fish and amphibians.
These groups are prioritised because more scientific knowledge and validated testing methods are available for them than for other animals.
Our assessments inform decisions taken by the European Commission and EU Member States, who regulate the use of pesticides and other chemical substances in the food chain.
We also support the development of harmonised approaches for risk assessmentA specialised field of applied science that involves reviewing scientific data and studies in order to evaluate risks associated with certain hazards. It involves four steps: hazard identification, hazard characterisation, exposure assessment and risk characterisation of endocrine active substances and reliable testing methods.
The European Chemicals Agency (ECHA)’s scientists identify and evaluate endocrine disruptors for other chemical substances such as biocides.
EU framework
Pesticides
- Regulation EC 1107/2009 regulates the authorisation and marketing of plant protection products in the EU.
- Regulation (EU) 2018/605 sets out scientific criteria for the determination of endocrine disrupting properties of plant protection products.
- Pesticides identified as endocrine disruptors that may harm humans or non-target organisms cannot normally be approved in the EU.
- Non-approval does not apply to substances where exposure is negligible under the conditions of use, and to substances deemed necessary to control a serious danger to plant health which cannot be contained by other available means, including non-chemical methods.
For more information
- European Commission:
- Endocrine disruptors