The Dangers of Endocrine Disrupting Chemicals


The human body is governed by hormones, with the endocrine system regulating everything from sleep-wake cycles and stress levels to mood, metabolism, and reproductive cycles. When hormone regulation in your body is disrupted, this can cause all sorts of physiological problems. So, it’s important to understand how chemicals affect hormones, and what the regulators are doing about it.

The endocrine system governs all aspects of your body over a lifetime, from puberty to circadian rhythm.
The endocrine system governs all aspects of your body over a lifetime, from puberty to circadian rhythm.

What is an endocrine disruptor?

Endocrine disrupting chemicals (EDCs) are substances that alter the hormonal and homeostatic systems of living organisms. This in turn interferes significantly with primary regulatory processes of the body like growth, metabolism, stress response, reproduction, sexual development, gender behaviour, and foetal development. The U.S. Environmental Protection Agency describes an EDC as “an agent that interferes with the synthesis, secretion, transport, binding, or elimination of natural hormones in the body that are responsible for the maintenance of homeostasis, reproduction, development and/or behaviour.”

EDCs can be classified under three broad categories, found in products as follows:

  1. Pesticides, like DDT and chlorpyrifos, that can disrupt the normal functioning of neuronal and reproductive systems 
  2. Chemicals in products that we use in our daily lives, such as lead found in jewellery, children’s products and paints, or brominated flame retardants used in textiles, building materials, and electronics
  3. Additives to food contact materials and other plastic packaging, such as bisphenol-A (BPA), phthalates, and phenols

Why are they problematic?

Given the wide variation in the structure of EDCs, it is difficult to identify a particular mechanism of action in living organisms. However, several studies show that they can completely, or at least in part, imitate naturally occurring hormones like androgens (male sex hormones), oestrogens (female sex hormones), and thyroxine, producing hyperactivity of those hormones in the body. Some EDCs also act as antagonists, preventing the natural hormones from binding their own receptors and thus disrupting the hormonal signalling pathways. EDCs can also indirectly block the natural functioning of the hormones by altering their metabolism in the liver.

Data from epidemiological studies over the last 50 years show evidence of increased incidence and prevalence of certain diseases like obesity, diabetes, and fertility issues associated with EDCs, as well as breast, prostate, and testicular cancer. A higher risk of hormone-related cancer has been seen in more industrialised countries on account of EDC prevalence, and children fed on infant soy formula (containing the EDC soy isoflavone) developed autoimmune thyroid diseases as teenagers.

What’s being done about them?

The use of overtly harmful EDCs has started to be phased out as chronic health effects have been fully realised. The U.S. Food and Drug Administration advised against prescription of a synthetic form of oestrogen, DES (diethylstilbestrol), due to it being linked to a very rare form of vaginal cancer. Exports and use of DDT and other polychlorinated biphenyl compounds were banned in the US in the 1970s due to their potential risks to the environment and human health. 

Many milder EDCs are still present in industrial and consumer goods, which, when combined over a lifetime, can still have significant physiological effects. Known EDCs must now be declared on chemical safety data sheets (SDS) in the EU, and manufacturers may market products as BPA- or phthalate-free or non-toxic to indicate an absence of harmful chemicals to consumers.

Plastic products, including microplastics, are a concern due to their now-unwavering presence globally, leaching out EDCs into the environment.
Plastic products, including microplastics, are a concern due to their now-unwavering presence globally, leaching out EDCs into the environment.

Revision 7 of the GHS, adapted by the EU, has now mandated the identification of EDCs and the communication of information surrounding any endocrine disruptors existing in a chemical product. This comprises additional information to be included in European SDS, namely affecting Section 2—Hazard Identification, Section 3—Ingredients table, Section 11—Toxicological Information, and Section 12—Ecological Information.

SDS Section 2.3 (“Other Hazards”) must specify ingredients that are listed as Endocrine Disruptors in the Europe Regulation (EU) 2018/1881 Specific Requirements for Endocrine Disruptors.

Section 3 of the SDS should indicate endocrine disrupting substances and concentrations which meet the criteria for classification in accordance with Regulation (EC) No 1272/2008. The EDC must be present in a concentration of equal to or greater than 0.1%. Chemwatch has enacted this by adding a superscript “e” to relevant ingredients classified as endocrine disruptors, and by updating the legend in section 3.2.

In Section 11.2.1, a new section called “Endocrine Disruption Properties” was added for health effects. This information centres on adverse health effects caused by ED properties, where they are available for any of the substances contained within the mixture. 

For Section 12.6, the old “Other adverse effects” section is replaced by “Endocrine Disrupting Properties”, with respect to environmental effects. Where possible information on ED properties of ingredients must be stated. 

Chemwatch is here to help

If you want to know more about the health effects of chemicals, or how to minimise risk while working with chemicals, we’re here to help. We have tools to help you with mandatory reporting, as well as generating SDS and Risk Assessments. We also have a library of webinars covering global safety regulations, software training, accredited courses, and labelling requirements. For more information, contact us today at sa***@ch*******.net.


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