Trimethylpentanediol/Isophthalic Acid/Trimellitic Anhydride Copolymer
AKA “Polyester Copolymer, Film-Forming Polymer
Acid
Ingredient Facts
Trimethylpentanediol/isophthalic acid/trimellitic anhydride copolymer
AKA: Polyester Copolymer, Film-Forming Polymer
Acid · Film Forming · EWG: 4
Synthetic
Occlusive
Acid
Not Clean
1,3-Isobenzofurandione, 5-carboxy-, polymer with 1,3-benzenedicarboxylic acid and 2,2,4-trimethyl-1,3-pentanediol
CAS #
92-44-4
State
Solid
See origin →
Functions
Film Forming
Creates a physical seal on skin to lock moisture in and keep irritants out. The "slugging" ingredient — barrier protection.
Viscosity Controlling
Creates Protective Barrier
Controls Viscosity
Creates protective layer
Controls product thickness
Traditional Use
A synthetic polymer developed for modern cosmetics as a film-forming and water-resistant agent. Used in long-wear makeup formulations to improve adherence and durability.
Skin Types
all-skin-types
Best For
General
Pregnancy & Breastfeeding Safe
Yes
EWG
4
CIR
Safe as used
Pregnancy
Yes
CIR Safety Findings
medical-approval
all-shades-safe
Potential Sensitizer
Regulatory Status
USApermitted
EUrestricted
JAPANrestricted
CANADArestricted
Verified Jun 2026
Data: CosIng · EWG · CIR