Regularly, magazines, radio and television shows and some blogs sow discredit on endocrine disruptors, creating a phenomenon of fear. What is the reality?

"Traces of dozens of endocrine disruptors in the hair of children aged 10 to 15", "The risks you take when you wear makeup", "When my cream gives me cancer" ... So many headlines that send shivers down your spine and categorically point the finger at cosmetics. However, the problem of endocrine disruptors is more subtle and clearly more complex.

What is an endocrine disruptor?

According to the WHO definition taken up by the European Commission: “An endocrine disruptor is an exogenous substance or mixture altering the functions of the endocrine system and inducing adverse effects on the health of an intact organism, its descendants or (sub)populations.”

These are molecules foreign to the body, of synthetic origin (products from the chemical industry) or natural (hormones and phytoestrogens).

What are their effects?

Omnipresent in everyday life, they act by imitating and modifying the metabolism of natural hormones. Organisms can thus be exposed by multiple routes (ingestion, inhalation, skin contact) to tiny doses of several compounds, the various effects of which could combine. Endocrine disruptors (EDs) are suspected of inducing pathologies such as obesity, diabetes or autism, fertility disorders (possibly over several generations) such as deterioration of sperm quality in boys or conversely early puberty in girls, or even hormone-dependent cancers (breast, uterus, prostate, testicles). Endocrine disruptors are found in pesticides, but also in household products , furniture , clothing and cosmetics .

The dose effect and the cocktail effect

Traditionally, the harmful effects of chemicals are described in toxicology studies as proportional to the dose tested.

No usual dose effect

Normally, a low dose produces no effect, a medium dose causes weak toxic effects, and a high dose induces more pronounced or dangerous effects. In the case of EDCs, toxicologists have noted that some of these chemicals can have more significant (or even opposite) effects at low doses than those observed at high doses.

But a cocktail effect

According to the WHO, humans are exposed daily to a large number of different endocrine disruptors, from different products: food packaging, plastic bottles, cleaning products, paints, baby wipes, cosmetic products. While each of them can have harmful effects on the body, it is above all the cocktail effect linked to their interactions that worries scientists. And it is the mixture of these molecules in the body that has effects that are still unknown.

Many suspects, but none proven guilty

In cosmetics, the list of supposed endocrine disruptors varies. No database is really reliable.

The famous suspects

If we want to be exhaustive, here is the list of PE:

• Chemical sunscreens : avobenzone, ethylhexyl methoxycinnamate, benzophenone-1 and -3, oxybenzone, octocrylene, octinoxate, 4-methylbenzylidene camphor (4-MBC)
• Antioxidants: BHA AND BHT
• Volatile silicones: cyclopentasiloxane, others having already been banned
• Preservatives: butylparaben, propylparaben, methylparaben and ethylparaben (5 parabens were banned by regulation no. 1004/2014.)
• But also: salicylic acid, diethyl phthalate, EDTA, PEG, Resorcinol in hair dyes, aluminum salts in deodorants, antibacterial triclosan (very little present in recent years)

Often contradictory studies

The problem is that scientists themselves cannot agree on these substances. For each, there are as many studies that exonerate them as there are others that accuse them. And in the end, no study proves or clearly states the dangers of these molecules.

Cosmetic Regulations in Constant Evolution

The REACH regulation and PE

In France, cosmetics are governed by European Regulation (Regulation (EC) No. 1223/2009 of the European Council and of the Parliament of 30 November 2009). However, this does not provide for specific provisions on PE. It is the REACH regulation (Registration, Evaluation and Authorisation of Chemicals in English) which manages environmental concerns related to chemical substances contained in cosmetics.

Endocrine disruptors are regulated in the REACH regulation by article 57: substances with endocrine disrupting properties can be identified as SVHC (substances of very high concern) in the same way that other categories of dangerous chemical substances are classified as CMR (carcinogenic, mutagenic, toxic to reproduction) or PBT (persistent, bioaccumulative and toxic). A substance classified as SVHC can no longer be produced or used in the EU. Endocrine disruptors can also be banned in certain uses, these are “restrictions.”

A Committee of European experts

Studies in progress

The SCCS is regularly contacted by the European Commission for new assessments of potentially harmful substances and those particularly suspected of endocrine disruption.

Since 2019, a list of 28 potential endocrine disruptors has been established for cosmetics. The following are currently being evaluated as a priority: Kojic acid, Benzophenone 1 and 3, Benzyl Salicylate, BHT, Genistein, Homosalate, Octocrylene, Propylparaben, Resorcinol, Triclosan, 4-Methylbenzylidene camphor (4-MBC).
On February 15, 2021, 10 substances were added, including two parabens (butylparaben and methylparaben), five UV filters (including benzophenone 1, octocrylene and octinoxate), BHA and salicylic acid.
Opinions are expected in the coming months or year.

Ultimately, the problem with endocrine disruptors is mainly that of the precautionary principle. Nothing has been truly and scientifically proven yet. So if they are not absolutely necessary (the question arises in particular for sunscreens), should we use endocrine disruptors and accept the risks they represent? In the meantime, we can scan the composition of products with apps that signal their presence and turn to simpler and cleaner formulas.