Styrene/Acrylates/Ammonium Methacrylate Copolymer

This is a film-forming polymer built from styrene, ammonium methacrylate, and an acrylic or methacrylic acid monomer, used to lay down a flexible, water-resistant film that helps hold hair styles, sets nail polish, or extends makeup wear. CIR reviewed it within its broad acrylates copolymer family and found no evidence of a safety concern in current cosmetic use; the starting monomers have their own toxicology, but the finished, polymerized copolymer is considered safe when formulated to avoid irritation.

Cosmetic information for general education, not medical advice. A verdict is a reading of the published evidence, never a guarantee for your skin: any ingredient can irritate someone, so patch test new products and see a professional if you react. Concern is graded on cited evidence, never on hazard-score lists. See how we score.