Octylmethicone is a clear, colorless liquid composed of trisiloxane and an octyl group attached to a silicon atom in the middle. It is low molecular weight, low viscosity, and has moderate volatility. It has good compatibility with organic UV filters, making it easy to formulate in sunscreen formulations. The compact trisiloxane backbone provides a lightweight, non-greasy skin feel and improved spreadability.
Because of these properties, octylsimethicone is used heavily in clear and smooth sunscreen formulas, providing a smooth skin feel and easy glide on the skin.