Styrene/Isoprene Copolymer Good Occlusive-opacifying agent No known benefits Styrene/Isoprene Copolymer at a glance Synthetic polymer Film-forming agent and opacifier Sometimes used to make hydrocolloid bandages Ruled safe as used in cosmetics Styrene/Isoprene Copolymer description Styrene/isoprene copolymer is a synthetic polymer used in cosmetics primarily as a film-forming agent and opacifier, meaning it is added to a material to make it less transparent. It is also one of several polymers that can be used to make hydrocolloid bandages. The independent Cosmetic Ingredient Review has ruled styrene/isoprene copolymer safe in its current usage in cosmetics. Typical use levels of styrene/isoprene copolymer in cosmetics ranges from 0.89% to 4.2%. The use level increases to 7–14% when this polymer is used in hydrocolloid patches. Related ingredients: Hydrocolloid