Polyurethane-21

AKA: PU-21

Synthetic

Occlusive

Not Clean

Methylenedicyclohexanediisocyanate, polymer with 2,2-di(hydroxymethyl)propanoic acid and 2,2'-oxybisethanol/2-oxepanone copymer, tris(2-hydroxyethyl)amine salts

CAS #

-

Form

Powder

Functions

Film Forming

Creates a physical seal on skin to lock moisture in and keep irritants out. The "slugging" ingredient — barrier protection.

Creates Protective Barrier

Traditional Use

Modern synthetic polymer created for cosmetics to function as a film-forming and conditioning agent. Designed to enhance product application and wear properties.

EWG

CIR

Safe as used

Pregnancy

Yes

CIR Safety Findings

Not a Sensitizer

medical-approval

all-shades-safe

Regulatory Status

USA✔ permitted

EU✔ permitted

JAPAN✔ permitted

CANADA✔ permitted

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-reviewednone on file

⚖️Regulatory1 listing →

🛡️Safety-assessed1 review →

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

Verified Jun 2026

Data: CosIng · EWG · CIR