Polyurethane-21
AKA “Polyurethane-21, PU-21
Ingredient
Ingredient Facts
Polyurethane-21
AKA: PU-21
Ingredient · Film Forming · EWG: 4
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
See origin →
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.
Skin Types
all-skin-types
Best For
General
Pregnancy & Breastfeeding Safe
Yes
EWG
4
CIR
Safe as used
Pregnancy
Yes
CIR Safety Findings
Not a Sensitizer
medical-approval
all-shades-safe
Regulatory Status
USApermitted
EUpermitted
JAPANpermitted
CANADApermitted
Verified Jun 2026
Data: CosIng · EWG · CIR