ECHA's Committees Support Restricting Silicone-Based Substances in Cosmetic and Other Consumer Products

Proposed regulation restricts leave-on uses & extends current restrictions for rinse-off products

The cyclosiloxanes octamethylcyclotetrasiloxane (D4), decamethylcyclopentasiloxane (D5), and dodecamethylcyclohexasiloxane (D6) are cyclic volatile methyl siloxane (cVMS) substances with four, five, and six siloxane groups, respectively. Their use in cosmetics is one of their most important applications. D5 and D6 are commonly used in cosmetics as emollients, hair and skin conditioning ingredients, and solvents. The ingredients can be used in hair conditioning products where the product is washed off when used or in skincare products, personal deodorants, and color cosmetics where the product is left on the skin. Restrictions currently apply where D4 and D5 are rinsed off; the new proposed restriction will apply to all leave-on uses and extend the rinse-off restriction to D6.

Current restrictions

D4 is prohibited for use in cosmetics in the EU as per cosmetic Regulation (EC) No. 1223/2009. The EU Scientific Committee for Consumer Products (SCCP) concluded in its opinion (SCCP/0893/05) that they were unable to assess the risk of D4 to consumers when it is used in cosmetics.

D4, D5, and D6 were identified by the European Chemicals Agency's (ECHA) Member State Committee as a Substance of Very High Concern (SVHC), substances with persistent, bioaccumulative and toxic (PBT)/very Persistent and very Bio-accumulative (vPvB) properties.

D4 and D5 are restricted for use in rinse-off cosmetic products with a concentration equal to or greater than 0.1% by weight; this restriction entered into force on 30 January 2018 and applied to all products placed on the EU market from January 31, 2020.

New proposed restrictions

D4, D5, and D6 in leave-on cosmetics will be permitted only to a maximum concentration of 0.1%.

D6 in rinse-off cosmetic products will be permitted in concentrations up to 0.1%, matching the current limitations in place for D4 and D5 in rinse-off products.

Next steps

The proposed transition period is five years from publication of the amending regulation. To ensure a seamless transition and avoid the cost of stock and inventory write off, cosmetic brand owners, retailers, and manufacturers should act on the reformulation to comply with the restrictions now. In addition, D4, D5, and D6 may be present as "hidden" impurities of silicone polymers, so a comprehensive review of cosmetic formulations is also needed to comply with EU regulations.

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