Adipic Acid/Neopentyl Glycol/Trimellitic Anhydride Copolymer

AKA: Polyester polymer, Film former

Synthetic

Occlusive

Acid

Clean

Hexanedioic acid, polymer with 1,3-dihydro-1,3-dioxo-5-isobenzofurancarboxylic acid and 2,2-dimethyl-1,3-propanediol

CAS #

28407-73-0

Form

Powder

State

Solid

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

Antioxidant Protection

Fights Bacteria

Traditional Use

A synthetic polymer created through modern chemical synthesis in the late 20th century. Designed as a cosmetic film-former and binding agent for improved product performance.

EWG

CIR

Insufficient data

Pregnancy

Yes

CIR Safety Findings

Not a Sensitizer

ewg-1

pregnancy-nursing-safe

all-shades-safe

Regulatory Status

USAunder review

EU⚠ restricted

JAPAN⚠ restricted

CANADA⚠ restricted

Regulatory Agencies

EWG CIR FDA EU COSING Health Canada

Skin Types

●all-skin-types, gentle

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