Trimethylsiloxysilicate

Safety Information

United States (U.S.)

Expert Panel for Cosmetic Ingredient Safety

The Expert Panel reviewed the safety of silica silylate, silica dimethyl silylate, trimethylsiloxysilicate and trifluoropropyldimethyl/trimethylsiloxysilicate together because these large polymers have similar structures and are used in cosmetics in similar ways. These ingredients are stable solids that are not soluble in water and are therefore not likely to penetrate the skin.

The Expert Panel reviewed information that showed that these compounds did not cause adverse effects. They were not genotoxic or carcinogenic. Dermal application of these compounds did not result in significant irritation, and these compounds were not sensitizers.

Based on the available data, the Expert Panel concluded that silica silylate, silica dimethyl silylate, trimethylsiloxysilicate and trifluoropropyldimethyl/trimethylsiloxysilicate are safe as used when formulated and delivered in the final product not to be irritating or sensitizing to the respiratory tract.

European Union (EU)

Silica silylate, silica dimethyl silylate, trimethylsiloxysilicate and trifluoropropyldimethyl/trimethylsiloxysilicate may be used in cosmetics and personal care products marketed in Europe according to the general provisions of the Cosmetics Regulation of the European Union.

Trimethylsiloxysilicate

What Is It?

Silica silylate, silica dimethyl silylate, trimethylsiloxysilicate and trifluoropropyldimethyl/trimethylsiloxysilicate are siloxane polymers. Siloxane polymers are polymers in which the backbone structure consists of alternating silicon and oxygen atoms.

These ingredients are solids that are not soluble in water. In cosmetics and personal care products, these siloxane polymers may be used in bath products, eye makeup, makeup, lipstick, nail polish, as well as hair and skin care products.

Why Is It Used?

The following functions have been reported for the silylate ingredients.

Anticaking agent — Silica Dimethyl Silylate
Antifoaming agent — Trimethylsiloxysilicate, Silica Silylate
Binder — Trifluoropropyldimethyl/Trimethylsiloxysilicate
Bulking agent — Silica Dimethyl Silylate, Silica Silylate

Skin conditioning agent — emollient – Silica Silylate, Trifluoropropyldimethyl/Trimethylsiloxysilicate
Skin conditioning agent — occlusive – Trimethylsiloxysilicate
Slip modifier — Silica Dimethyl Silylate
Viscosity increasing agent — nonaqueous – Silica Dimethyl Silylate

Scientific Facts

Silica silylate is a silica compound in which some of the hydroxyl groups on the surface have been replaced by trimethylsiloxy groups. Instead of trimethylsiloxy groups, silica dimethyl silylate has dimethyl silyl groups which replace some of the surface hydroxyl groups.

Trimethylsiloxysilicate is a network of polysilicic acid units with trimethylsilyl groups at the ends. In contrast, trifluoropropyldimethyl/trimethylsiloxysilicate is a network with a mixture of trimethylsilyl groups and trifluoropropyldimethylsilyl groups at the ends.