Ingredient review
Polyurethane-36
INCI: Polyurethane-36
A synthetic polymer that helps makeup and sunscreen stay put without feeling heavy or stiff.
In plain English
Polyurethane-36 is a synthetic ingredient that forms a thin, flexible film on your skin or hair. Think of it like a clear, breathable raincoat: it helps makeup last longer, keeps sunscreen from rubbing off, and gives hair products hold without making them crunchy. It's commonly found in long-wear foundations, waterproof mascaras, and sunscreens that claim to be water-resistant.
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
Polyurethane-36 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 Polyurethane-36.
- 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
Polyurethane-36 is a synthetic polymer belonging to the polyurethane family. It is created by reacting a diisocyanate with a polyol, resulting in a flexible, film-forming material. In cosmetics, it is used as a film former and viscosity modifier.
How it works
When applied, the water or solvent in the product evaporates, leaving behind a thin, continuous film of Polyurethane-36 on the skin or hair. This film is flexible, meaning it moves with your skin without cracking, and is water-resistant, helping the product stay in place longer. It also helps other ingredients, like pigments or UV filters, adhere evenly.
Pros
Long-lasting wear
Helps makeup and sunscreen resist smudging, fading, and rubbing off throughout the day.
Comfortable feel
Unlike some older film formers, Polyurethane-36 creates a flexible film that doesn't feel tight or stiff on the skin.
Cons and cautions
Synthetic origin
It is a man-made polymer, which may be a turn-off for those seeking natural or minimal-ingredient products.
Potential for buildup
If not properly cleansed, repeated use can lead to a slight film buildup on skin or hair, requiring a thorough double cleanse.
Best for
- Anyone wanting long-lasting makeup or sunscreen
- People with oily skin who need products to stay in place
Use caution if
- Those who prefer 100% natural or silicone-free routines (though not a silicone, it is synthetic)
Usage tips
Safety summary
Polyurethane-36 is considered safe for use in cosmetics at typical concentrations. It has low irritation and comedogenic potential. The Cosmetic Ingredient Review (CIR) panel has reviewed similar polyurethane polymers and found them safe as used.
Research notes
Safety assessments are based on the broader class of polyurethane polymers used in cosmetics. Individual studies on Polyurethane-36 are limited, but the ingredient is widely used and accepted by regulatory bodies. The CIR has reviewed related polyurethane film formers and concluded they are safe when formulated properly.
Common label clues
- Typical concentration
- 0.5% to 5%
- Regulatory status
- Approved for use in cosmetics in the US (FDA), EU (CosIng), and other major markets. No known restrictions at typical use levels.
- Common uses
- Long-wear foundations, Waterproof mascaras, Sunscreens, Hair styling products
- Environmental note
- As a synthetic polymer, its biodegradability is limited. However, it is used in low concentrations and is not considered a major environmental concern compared to microplastics.
Good to know
- Polyurethane-36 is not a silicone, though it shares some similar film-forming properties.
- It is often used in 'transfer-proof' lipsticks and long-wear foundations.
Common questions
What is Polyurethane-36 in beauty products?
Polyurethane-36 is a synthetic ingredient that forms a thin, flexible film on your skin or hair. Think of it like a clear, breathable raincoat: it helps makeup last longer, keeps sunscreen from rubbing off, and gives hair products hold without making them crunchy. It's commonly found in long-wear foundations, waterproof mascaras, and sunscreens that claim to be water-resistant.
What does Polyurethane-36 do in a beauty product?
When applied, the water or solvent in the product evaporates, leaving behind a thin, continuous film of Polyurethane-36 on the skin or hair. This film is flexible, meaning it moves with your skin without cracking, and is water-resistant, helping the product stay in place longer. It also helps other ingredients, like pigments or UV filters, adhere evenly.
Is Polyurethane-36 safe for most people?
Polyurethane-36 is considered safe for use in cosmetics at typical concentrations. It has low irritation and comedogenic potential. The Cosmetic Ingredient Review (CIR) panel has reviewed similar polyurethane polymers and found them safe as used.
Who should be careful with Polyurethane-36?
Those who prefer 100% natural or silicone-free routines (though not a silicone, it is synthetic)
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.