What it is
Polyurethane-1 is a synthetic polymer built from urethane linkages, classed in cosmetics as a film former. When the product dries it forms a continuous, flexible film on the skin that can improve wear, even deposition, and the cohesion of pigments or other actives. In sunscreens it is used to help create an even, long-wearing layer.
Safety & warnings
Cosmetic-grade polyurethane film formers are high-molecular-weight, essentially inert polymers that sit on the surface of the skin and are generally well tolerated. They are not recognized fragrance allergens. As film-forming polymers they are not typically associated with comedogenicity at cosmetic use levels.
Origin & sourcing
Fully synthetic polymer produced by reacting polyols with isocyanate-derived urethane chemistry.
Questions everyone asks
What is the role of polyurethane-1 in a sunscreen?
It is a film former that helps the product dry down into an even, flexible, cohesive layer on the skin.
Does polyurethane-1 absorb into the skin?
No. It is a large polymer that forms a film on the skin surface rather than penetrating it.