Polybutyl Methacrylate

AKA: PBMA, Poly(butyl methacrylate)

Synthetic

Occlusive

Not Clean

Homopolymer of butyl methacrylate

CAS #

9003-63-8

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

Developed in the mid-20th century as a synthetic acrylic polymer. Used in cosmetics since the 1960s as a film-forming agent to provide long-lasting wear and water resistance in nail polishes and makeup products.

EWG

CIR

Safe as used

Pregnancy

—

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

The paper trail

🔬Peer-reviewed1 paper →

⚖️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