Cetyl Dimethicone. (45-55% Hexadecylmethylsiloxane)-(Dimethylsiloxane) Copolymer by Alfa Chemistry is a silicone that enhances spreading behavior, which results in better pigment and organic/inorganic UV filter distribution in emulsion systems. (45-55% Hexadecylmethylsiloxane)-(Dimethylsiloxane) Copolymer... view more