Trimethylsiloxy/dimethiconyl/polymethylsilsesquioxane
A cosmetic ingredient used as film forming in skincare, haircare, and personal-care products sold in the European Union.
What is it?
Trimethylsiloxy/Dimethiconyl/Polymethylsilsesquioxane is a siloxane polymer that is made by the hydrolysis and condensation of Trimethylchlorosilane, Bis-Chloro Dimethicone and Bis-Chloro Chloro Methicone.
What does it do?
Trimethylsiloxy/dimethiconyl/polymethylsilsesquioxane is listed in the EU cosmetic ingredient inventory with the following declared functions:
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Film forming
forms a thin continuous film on skin, hair, or nails — used in long-wear makeup, sunscreens, and hairsprays
EU regulatory status
Trimethylsiloxy/dimethiconyl/polymethylsilsesquioxane is allowed for use in cosmetic products in the European Union under Regulation 1223/2009. It is not subject to a specific Annex restriction at the time of writing.
Frequently asked questions
What is Trimethylsiloxy/dimethiconyl/polymethylsilsesquioxane?
Trimethylsiloxy/dimethiconyl/polymethylsilsesquioxane is a cosmetic ingredient catalogued in the EU CosIng database. Trimethylsiloxy/Dimethiconyl/Polymethylsilsesquioxane is a siloxane polymer that is made by the hydrolysis and condensation of Trimethylchlorosilane, Bis-Chloro Dimethicone and Bis-Chloro Chloro Methicone.
Is Trimethylsiloxy/dimethiconyl/polymethylsilsesquioxane allowed in cosmetics in the EU?
Yes. Trimethylsiloxy/dimethiconyl/polymethylsilsesquioxane is allowed for use in cosmetic products in the EU under Regulation 1223/2009.
What does Trimethylsiloxy/dimethiconyl/polymethylsilsesquioxane do in cosmetic products?
Trimethylsiloxy/dimethiconyl/polymethylsilsesquioxane is declared in the EU cosmetic ingredient inventory with these functions: film forming.
Related ingredients
Source: EU CosIng database (European Commission). This page is derived from public-sector information published by the European Commission. · Last updated: 07/05/2026