Isobutylene/Isoprene Copolymer
AKA “Butyl rubber, isoprene rubber copolymer”
Ingredient
Ingredient Facts
Isobutylene/isoprene copolymer
AKA: Butyl rubber, Isoprene rubber copolymer
Ingredient · Viscosity Controlling · EWG: 4
Synthetic
Not Clean
1,3-Butadiene-, polymer with 2-methyl-1-propene
CAS #
9010-85-9
Form
Liquid
State
Solid
See origin →
Functions
Viscosity Controlling
Controls Viscosity
Traditional Use
Synthetic polymer developed in the mid-20th century as a film-forming agent in cosmetics. Used in skincare and color cosmetics to create a protective layer on the skin and improve product wear.
Skin Types
●all-skin-types
Best For
General
Pregnancy & Breastfeeding Safe
Yes
Verified Jun 2026
Data: CosIng · EWG · CIR