The European Union has further tightened regulations on the use of silicones D5 and D6 in cosmetic products, aiming to mitigate their environmental impact. This move comes as part of an update to the REACH (Registration, Evaluation, Authorisation, and Restriction of Chemicals) regulation.
These changes expand upon existing restrictions for octamethylcyclotetrasiloxane (D4) and decamethylcyclopentasiloxane (D5). D4, already banned in cosmetics since January 1, 2022, due to its suspected endocrine-disrupting effects, remains off-limits under the new regulations. Similarly, D5 has faced restrictions limiting its concentration to 0.1% in rinse-off cosmetic products since January 31, 2020.
The new regulation, effective from June 6, 2026, prohibits the marketing of D4, D5, and dodecamethylcyclohexasiloxane (D6) as standalone substances, as components of other substances, or in mixtures at concentrations equal to or exceeding 0.1% by weight. Specifically for the cosmetics industry, these restrictions will extend to leave-on products as well. By June 6, 2027, D5 will also be restricted in leave-on cosmetics, and D6 will face similar restrictions in both rinse-off and leave-on products.
These measures are based on findings from the European Chemicals Agency’s (ECHA) Risk Assessment Committee (RAC), which identified cosmetic products as significant contributors to environmental contamination with these substances. D4, D5, and D6 are known to accumulate in aquatic environments and the atmosphere, posing ecological risks.
