Ingredient review
Propylene Glycol/Sebacic Acid/Trimellitic Anhydride Copolymer
INCI: PROPYLENE GLYCOL/SEBACIC ACID/TRIMELLITIC ANHYDRIDE COPOLYMER
A synthetic polymer that helps products stay put longer, but offers no active skincare benefit.
In plain English
This ingredient is a type of plastic-like polymer that forms a thin, flexible film on your skin or hair. It's added to products like sunscreen, foundation, and mascara to make them water-resistant and long-lasting. Think of it as a clear, invisible coat that helps your makeup or SPF stay in place without feeling stiff or heavy.
Review score
Safety, usefulness, and evidence
Potentially useful with some tradeoffs
The evidence base is useful, but some claims depend heavily on the formula.
Risk flags are low for most users, though the finished product can still irritate.
- Source
- synthetic
- Evidence
- moderate
- Irritation
- low
- Clogging risk
- low
Quick decision guide
Useful, but context matters
Propylene Glycol/Sebacic Acid/Trimellitic Anhydride Copolymer is generally a lower-concern ingredient when the full formula suits your skin.
Plain-English read
Treat this as a practical screening step before you compare products that contain this ingredient.
- Step 1Start with the score, then check the irritation and clogging risk before judging Propylene Glycol/Sebacic Acid/Trimellitic Anhydride Copolymer.
- Step 2Use the "Best for" and "Use caution if" sections to match the ingredient to your skin, not just to a marketing claim.
- Step 3If a product stings, breaks you out, or worsens irritation, judge the finished formula and stop using it even if the ingredient scores well.
Score terms in plain English
Irritation risk
lowLess likely to sting, burn, or bother most users, though sensitive skin can still react.
Clogging risk
lowLess likely to feel heavy or contribute to clogged pores for most skin types.
Evidence level
moderateThere is useful support, but formula details and claim strength still matter.
What it is
A synthetic copolymer created by reacting propylene glycol, sebacic acid, and trimellitic anhydride. It belongs to the polyester family and is engineered to form a durable yet flexible film.
How it works
When applied, the copolymer molecules link together as the solvent (water or alcohol) evaporates, creating a continuous, water-resistant film on the skin or hair. This film physically blocks water and sweat, helping other ingredients (like UV filters or pigments) stay put longer.
Pros
Boosts water resistance
Helps sunscreen and makeup stay effective even when you sweat or swim, reducing the need for frequent reapplication.
Flexible, comfortable wear
Unlike some older film-formers, this copolymer creates a pliable film that moves with your skin, so it doesn't feel tight or crack.
Cons and cautions
Requires thorough removal
Because it forms a water-resistant film, you'll likely need an oil-based cleanser or micellar water to fully remove it, which can be inconvenient.
No skincare benefit
This is a purely functional ingredient — it doesn't hydrate, soothe, or protect your skin beyond helping other ingredients stay in place.
Best for
- Anyone wanting longer-lasting makeup or sunscreen
- People who swim, sweat, or live in humid climates
Use caution if
- Those who prefer minimalist, water-only cleansing routines (may require double cleansing to remove)
- Individuals with very oily or acne-prone skin who find film-formers clogging
Usage tips
Safety summary
Generally recognized as safe for topical use at typical concentrations. Low irritation and comedogenic potential. The main concerns are environmental persistence and the need for thorough removal to avoid buildup.
Research notes
Safety assessments by the Cosmetic Ingredient Review (CIR) panel have concluded that similar polyester polymers are safe when formulated properly. However, specific studies on this exact copolymer are limited, and most evidence comes from broader polymer safety data.
Common label clues
- Typical concentration
- 1–10% in leave-on products; up to 20% in hair styling formulas
- Regulatory status
- Approved for use in cosmetics in the US (FDA), EU (CosIng), and many other regions. No concentration limits are imposed, but manufacturers must follow good manufacturing practices.
- Common uses
- Sunscreens, Waterproof mascaras, Long-wear foundations, Hair styling products
- Environmental note
- As a synthetic polymer, it is not readily biodegradable and may contribute to microplastic pollution. Some brands are moving toward bio-based or biodegradable alternatives.
Good to know
- This polymer is often listed under the trade name 'Polyester-5' on some ingredient databases.
- It is considered safe for use in cosmetics by major regulatory bodies, but its environmental persistence is a growing concern.
Common questions
What is Propylene Glycol/Sebacic Acid/Trimellitic Anhydride Copolymer in beauty products?
This ingredient is a type of plastic-like polymer that forms a thin, flexible film on your skin or hair. It's added to products like sunscreen, foundation, and mascara to make them water-resistant and long-lasting. Think of it as a clear, invisible coat that helps your makeup or SPF stay in place without feeling stiff or heavy.
What does Propylene Glycol/Sebacic Acid/Trimellitic Anhydride Copolymer do in a beauty product?
When applied, the copolymer molecules link together as the solvent (water or alcohol) evaporates, creating a continuous, water-resistant film on the skin or hair. This film physically blocks water and sweat, helping other ingredients (like UV filters or pigments) stay put longer.
Is Propylene Glycol/Sebacic Acid/Trimellitic Anhydride Copolymer safe for most people?
Generally recognized as safe for topical use at typical concentrations. Low irritation and comedogenic potential. The main concerns are environmental persistence and the need for thorough removal to avoid buildup.
Who should be careful with Propylene Glycol/Sebacic Acid/Trimellitic Anhydride Copolymer?
Those who prefer minimalist, water-only cleansing routines (may require double cleansing to remove) Individuals with very oily or acne-prone skin who find film-formers clogging
Research sources
Ingredient reviews are educational and are not medical advice. Patch test new products and ask a licensed clinician about persistent irritation, allergies, pregnancy-specific questions, or diagnosed skin conditions.