Styrene/Isoprene Copolymer
AKA “Styrene-Isoprene Copolymer”
Ingredient
Ingredient Facts
Styrene/isoprene copolymer
AKA: Styrene-Isoprene Copolymer
Ingredient · Film Forming · EWG: 1
Synthetic
Occlusive
Clean
Benzene, ethenyl-, polymer with 2-methyl-1,3-butadiene
CAS #
25038-32-8
Form
Liquid
State
Solid
See origin →
Functions
Film Forming
Creates a physical seal on skin to lock moisture in and keep irritants out. The "slugging" ingredient — barrier protection.
Opacifying
Creates Protective Barrier
Adds Opacity
Reduces Inflammation
Locks In Moisture
Wound Healing
Creates protective layer
Creates creamy opacity
Traditional Use
A synthetic polymer developed in the 20th century combining styrene and isoprene monomers. Used in cosmetics as a film-forming agent without traditional historical precedent.
Skin Types
●all-skin-types
Best For
General
Pregnancy & Breastfeeding Safe
Caution
EWG
1
CIR
Safe as used
Pregnancy
Caution
Restricted By
CIR Safety Findings
medical-approval
all-shades-safe
Regulatory Agencies
Hydrogenated Styrene/Isoprene Copolymer
European Commission
EU Cosmetic Ingredient Database (CosIng)
Styrene/Isoprene Copolymer
European Commission
EU Cosmetic Ingredient Database (CosIng)
Hydrogenated Styrene/Isoprene Copolymer
Environmental Working Group (EWG)
EWG Skin Deep Cosmetics Database
Styrene/Isoprene Copolymer
Environmental Working Group (EWG)
EWG Skin Deep Cosmetics Database
Verified Jun 2026
Data: CosIng · EWG · CIR