Silica Dimethyl Silylate

Silica Dimethyl Silylate is a treated silica used mainly as a thickener/anti-caking agent in anhydrous and silicone-based products, typically at low concentrations (about 0.1–5%), and it is generally considered non-reactive on skin. Clinical experience and patch-test data suggest low irritancy compared with many functional additives, but the particulate/absorbent nature can contribute to dryness or mild mechanical irritation in highly compromised barriers (e.g., active eczema), so it is not scored as fully inert. Safety Notes: Silica Dimethyl Silylate is used primarily as a hydrophobic thickener/gel former and suspending agent in anhydrous/oil-silicone systems; in many leave-on products (facial oils, primers, sunscreens, serums) it appears at low levels (~0.05–0.5%) to add slip, reduce greasiness, and help suspend pigments or UV filters. Typical functional use in emulsions and color cosmetics is commonly ~0.5–5% for structure and sensory modification, while high-strength consumer products like silicone putty primers, balm/gel textures, and some anhydrous foundations can reach ~10–15% to build a strong gel network and matte, blurring finish. It is far less common in rinse-off products and, when present, tends to stay at the low end because high levels can create excessive viscosity and poor rinsability.