What is an endocrine disruptor?

  • Endocrine Disruptors are chemicals that interfere with human and animal hormone systems, and are capable of altering hormone balance and embryo development. Find out how we can help with relevant studies.
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What is an endocrine disruptor?

Endocrine disruptors (EDs) are compounds which can alter the normal functioning of the endocrine system and cause developmental and reproductive effects in humans and animals. As both the exposed individual and its offspring. can be affected by endocrine disruption there are concerns about the longer-term impacts of endocrine disrupting chemicals for populations and ecosystems. 

A diverse array of organic chemicals have been identified to have endocrine disrupting effects, including polychlorinated biphenyls (PCBs), organochlorine pesticides, plasticizers, surfactants, pharmaceuticals, natural and synthetic estrogens as well as phyto- and mycoestrogens. Many of these compounds can alter activity of the endocrine system at orders of magnitude below concentrations previously thought to be harmful to humans and animals, which poses a major challenge for the chemical industry.

"Endocrine disruptors (EDs) are compounds which can alter the normal functioning of the endocrine system and cause developmental and reproductive effects in humans and animals"

"EU regulations for biocide products (2017/2100) and plant protection products (2018/605) now require products to be labelled as endocrine disruptors"

EU Regulations

Recent updates to the EU regulations for biocide products (2017/2100) and plant protection products (2018/605) now require products to be labelled as endocrine disruptors, if they have a demonstrated adverse effect in an individual or its offspring which is a consequence of an endocrine mode of action.  In response to this the OECD have recently published a conceptual framework for endocrine disruptors that includes guidelines for measuring the effects of suspected endocrine disruptors on morphology, sexual development and reproduction.  These guidelines identify biological markers that can be used to identify an endocrine mode of action.

Fera recruit the best. Karen Thorpe joins the team from York University

"Karen is an applied biologist working in the field of aquatic ecotoxicology for over 20 years. Karen understands the impacts of emerging environmental contaminants (including endocrine disruptors, pharmaceuticals, pesticides and plastics) on stress physiology and reproductive success of invertebrates and vertebrates, particularly fish. Part of Karen’s research work included a 10 year partnership with AstraZeneca in the UK, a global pharmaceutical company who focus is to push the boundaries of science to deliver life-changing medicines"

Karen Thorpe
Testimonial Background

Areas of Expertise

  • Fish physiology and reproduction

  • Endocrine disrupting chemicals

  • Combination effects of simple and complex mixtures of environmental stressors

  • Aquatic Ecotoxicology
This appointment bolsters an already established and well experienced team (including Steve Mattock, Rachel Benstead, Nick Jarratt & many more) in the design and conduct of ecotoxicology studies which includes studies to assess the toxicity of test articles to a range of species, including: Aquatic Ecotoxicology, Soil Organisms, Terrestrial Organisms
Meet karen

Karen Thorpe

Karen brings a wealth of experience in the Aquatic Ecotoxicology sector and expertise in using model fish species to study the influence of chemicals on fish physiology and reproduction. Karen gained further expertise in the effects of a range of chemical and physical stressors on the fish endocrine and immune system through her Postdoctoral Research at the Universities of Exeter, Basel and Prince Edward Island. 

Meet the scientists

Steve Mattock

Steve is the Head of the Ecotoxicology group at Fera. Steve has over 22 years practical experience of conducting ecotoxicology studies in both industry and contract research laboratories. In addition, he has also spent over 15 years working as an environmental risk assessor preparing ecotoxicology risk assessments for plant protection products, biocides and REACH related registrations.

Chris Sinclair

Chris Sinclair

Chris is an expert in regulatory environmental risk assessment processes, registration requirements and guidance for pharmaceuticals, veterinary medicines and pesticides, with over 15 years experience. He also leads on the ecotoxicology of chemicals (quantifying the impact chemicals have on terrestrial and aquatic organisms from earthworms and plants to fish and crustaceans). 

Our New State of Art Aquatic Laboratory - Opening September 2019

To complement the new E-Flows mesocosm ground breaking facility on site at Sand Hutton, Fera have also invested in the very latest aquatic testing laboratory equipment. This new facility consists of three testing laboratories and four water treatment/plant rooms, providing our experienced scientists with the space and latest instrumentation to deliver a premium analytical service for method validation and routine analysis required in support of compounds regulatory re-submissions or registrations.

Our Studies

Acute effects on Aquatic Organisms

Test Guideline Description
OECD 201 Freshwater Alga and Cyanobacteria (phylum of bacteria), Growth Inhibition Test 

OECD 235 Acute Immobilisation toxicity test to Chironomus riparius (harlequin fly, species of anon-biting midge) 
OECD 202Daphnia sp. (water flea) Acute Immobilisation Test (acute toxicity)
OECD 203 Fish, Acute (96-hour) Toxicity Test and prolonged toxicity to cold- and warm-water fish (e.g. rainbow trout, bluegill sunfish, carp, fathead minnow, zebrafish) 

Long term and chronic effects on Aquatic Organisms

The abundance of Chironomidae in freshwater systems and their sensitivity to environmental conditions make them ideal environmental indicators, as it allows us to reconstruct a highly detailed record of environmental and climatic change over thousands of years, accurate to within 1°C. Chironomids will only complete their life cycle if the environmental conditions are suitable. They are sensitive to:

  • summer temperatures
  • the relative acidity (pH) of the water
  • amount of nutrients in the lake water
  • the presence of pollution or trace metals
Test Guideline Description
OECD 233 Sediment-Water Chironomid Life-Cycle Toxicity Test Using Spiked Water or Spiked Sediment

OECD 218, 219 Prolonged sediment & spiked water toxicity test to Chironomus riparius (harlequin fly, species of anon-biting midge)
OECD 210Fish, Early-life Stage Toxicity Test
OECD 211 Daphnia magna (water flea) Reproduction Test (prolonged toxicity)
OECD 305Radiolabelled (or cold) bioaccumulation and/or metabolism in fish (Flow-through Fish test)
OECD 238/239 Myriophyllum (69 species of freshwater aquatic plants) Toxicity Tests
OECD 221 Lemna sp. (Common Duckweed) Growth Inhibition Test Algal growth inhibition (freshwater and marine)

NEW Studies

Test Guideline Description
OECD 236Fish Embryo Acute Toxicity
Trout Rtgill-W1 Gill Cell Assay
OECD 229/230Fish 21day Short Term Reproduction Assays
OECD 234 Fish Sexual Development Test

Other USEPA type tests, e.g. Ceriodaphnia and Effects Testing in Molluscs (Gastropods) will also be available.

Meet the rest of the team

Fera works closely with plant protection, biocide, animal health and chemical manufacturers to help develop effective, sustainable and safe products that enhance output whilst minimising adverse environmental impacts.

We're looking for the most talented and ingenious minds to help us tackle tomorrow's challenges with an innovative approach. Could you provide the answers?


Read more about what we do in Chemical Regulation

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