Isobutylene/Isoprene Copolymer

AKA: Butyl rubber, Isoprene rubber copolymer

Synthetic

Not Clean

1,3-Butadiene-, polymer with 2-methyl-1-propene

CAS #

9010-85-9

Form

Liquid

State

Solid

Skin Types

●all-skin-types

Best For

General

Pregnancy & Breastfeeding Safe

Yes

Functions

Viscosity Controlling

Controls Viscosity

The paper trail

🔬Peer-reviewednone on file

⚖️Regulatory1 listing →

🛡️Safety-assessed1 review →

Counts, not a verdict. A listing isn't a study. The trail, you decide.

EWG

CIR

Safe as used

Pregnancy

Yes

Concentration Guide

CIR lists it as not reported to be in use.

CIR · report published 2020

Regulatory Status

USA✔ permitted

EU⚠ restricted

JAPAN⚠ restricted

CANADA⚠ restricted

Regulatory Agencies

Verified Jun 2026

Data: CosIng · EWG · CIR