Polyisobutene
Use With Caution
Synthetic Polymer
Also Known As
Polyisobutylene
CAS Number
9003-27-4
What It Does
Film Former; Binder; Emollient
Why Oh Daisey Rates It This Way
Polyisobutene is a synthetic polymer used to improve texture, gloss, and water resistance in cosmetic formulations. It has low skin absorption and is considered safe for topical use, but due to its persistence in the environment and poor biodegradability, it is classified as Use with Caution.
Evidence Level
Strong
Sources
- https://www.cir-safety.org/; https://cosmetics.ec.europa.eu/cosing/