Ingredient review
Polyethylene/IPDI Copolymer
INCI: POLYETHYLENE/ISOPROPYL MALEATE/MA COPOLYOL
A synthetic film-former that helps products resist water and last longer, but offers no active skincare benefit.
In plain English
This ingredient is a type of plastic-like polymer that spreads into a thin, flexible film on your skin. It's used to make sunscreens more water-resistant and to help makeup stay put longer. Think of it as a clear, invisible shield that holds other ingredients in place.
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
Polyethylene/IPDI 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 Polyethylene/IPDI 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 derived from polyethylene and maleic acid derivatives, engineered to create a flexible, water-resistant film on the skin.
How it works
When applied, the polymer chains align and dry into a continuous film that physically blocks water and sebum from disturbing the product underneath. This film also helps active ingredients stay on the skin longer.
Pros
Boosts water resistance
Helps sunscreens and makeup stay effective even when you sweat or go swimming, so you don't have to reapply as often.
Improves wear time
Creates a durable film that keeps foundation and eye makeup from sliding off during the day.
Cons and cautions
No active skincare benefit
This ingredient only forms a film; it doesn't hydrate, soothe, or treat skin concerns.
Potential tackiness
On very oily skin, the film can feel slightly sticky or heavy, especially in humid weather.
Best for
- Anyone wanting longer-lasting sunscreen or makeup
- People who swim or sweat and need water-resistant products
Use caution if
- Those who prefer only naturally-derived ingredients
- Individuals with very sensitive skin who react to film-formers
Usage tips
Safety summary
Considered safe for topical use in cosmetics at typical concentrations. It is not absorbed into the skin and has a low irritation and comedogenic risk. No significant safety concerns have been reported.
Research notes
Limited independent research on this specific copolymer, but film-forming polymers in general are well-studied for safety and efficacy in cosmetic applications. The Cosmetic Ingredient Review (CIR) has reviewed similar polymers and found them safe as used.
Common label clues
- Typical concentration
- 0.5% to 5%
- Regulatory status
- Approved for use in cosmetics in the US (FDA), EU, and many other regions. No specific concentration restrictions are common.
- Common uses
- Sunscreens, Waterproof makeup, Long-wear foundations
- Environmental note
- As a synthetic polymer, it is not biodegradable. However, it is used in very low concentrations and is not known to accumulate in the environment.
Good to know
- This ingredient is often listed near the end of an ingredient list because it's used in small amounts.
- It is not absorbed into the skin; it stays on the surface as a protective layer.
Common questions
What is Polyethylene/IPDI Copolymer in beauty products?
This ingredient is a type of plastic-like polymer that spreads into a thin, flexible film on your skin. It's used to make sunscreens more water-resistant and to help makeup stay put longer. Think of it as a clear, invisible shield that holds other ingredients in place.
What does Polyethylene/IPDI Copolymer do in a beauty product?
When applied, the polymer chains align and dry into a continuous film that physically blocks water and sebum from disturbing the product underneath. This film also helps active ingredients stay on the skin longer.
Is Polyethylene/IPDI Copolymer safe for most people?
Considered safe for topical use in cosmetics at typical concentrations. It is not absorbed into the skin and has a low irritation and comedogenic risk. No significant safety concerns have been reported.
Who should be careful with Polyethylene/IPDI Copolymer?
Those who prefer only naturally-derived ingredients Individuals with very sensitive skin who react to film-formers
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.