Polyisoprene

AKA: Natural rubber, Cis-polyisoprene, Rubber

Synthetic

Clean

Homopolymer of 2-methyl-1,3-butadiene

CAS #

9003-31-0

Form

Powder

Functions

Viscosity Controlling

Controls Viscosity

Traditional Use

Synthesized in the early 20th century as an artificial rubber. Applied to cosmetics as a film-former and emollient, replacing natural rubber latex in formulations.

EWG

CIR

Safe as used

Pregnancy

Yes

CIR Safety Findings

Not a Sensitizer

medical-approval

all-shades-safe

Regulatory Status

USA✔ permitted

EU⚠ restricted

JAPAN⚠ restricted

CANADA⚠ restricted

Regulatory Agencies

EWG CIR FDA EU COSING Health Canada

Skin Types

●all-skin-types

Best For

General

Pregnancy & Breastfeeding Safe

Yes

The paper trail

🔬Peer-reviewed1 paper →

⚖️Regulatory1 listing →

🛡️Safety-assessed2 reviews →

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

Verified Jun 2026

Data: CosIng · EWG · CIR