Ingredient review

Polyurethane-81

INCI: Polyurethane-81

A synthetic film-former that helps makeup and hair products last longer, but may feel stiff or heavy for some.

beautyskincarehaircare

In plain English

Polyurethane-81 is a man-made polymer that forms a thin, flexible film on your skin or hair. Think of it like a clear, breathable plastic wrap that helps makeup stay put or holds a hairstyle in place. It's water-resistant but not completely waterproof, and it washes off with regular cleansers or shampoo.

Review score

Safety, usefulness, and evidence

3.8Good
3.8/ 5

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
How reviews are scored

Quick decision guide

Useful, but context matters

Polyurethane-81 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.

  1. Step 1Start with the score, then check the irritation and clogging risk before judging Polyurethane-81.
  2. Step 2Use the "Best for" and "Use caution if" sections to match the ingredient to your skin, not just to a marketing claim.
  3. 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

low

Less likely to sting, burn, or bother most users, though sensitive skin can still react.

Clogging risk

low

Less likely to feel heavy or contribute to clogged pores for most skin types.

Evidence level

moderate

There is useful support, but formula details and claim strength still matter.

What it is

A synthetic polymer belonging to the polyurethane family, designed to create a continuous film on the skin or hair surface. It is produced through a chemical reaction between diisocyanates and polyols, then modified for cosmetic use.

How it works

When applied, the polymer chains spread and link together as the solvent (water or alcohol) evaporates, forming a uniform, flexible film. This film physically locks in pigments or holds hair strands in shape, while still allowing some movement and moisture vapor to pass through.

Pros

Long-lasting wear

Helps foundation and mascara stay put for hours without smudging or fading, even in humid conditions.

Flexible film

Unlike some older polymers, polyurethane-81 creates a film that moves with your skin or hair, reducing cracking or flaking.

Cons and cautions

Potential stiffness

On very dry skin or in high concentrations, the film can feel slightly stiff or tight, especially around the eyes.

Hair buildup

If used daily in styling products, it may accumulate on hair strands, leading to dullness or difficulty restyling without a clarifying wash.

Best for

  • Anyone wanting long-lasting makeup or hairstyles
  • People with oily skin who need extra staying power

Use caution if

  • Those with very dry or dehydrated skin who prefer lightweight, breathable formulas

Usage tips

Apply in thin layers to avoid a heavy or sticky feel.
Use a gentle oil-based cleanser or micellar water to remove long-wear products containing this polymer.
For hair, alternate with a clarifying shampoo once a week to prevent buildup.

Safety summary

Polyurethane-81 is considered safe for cosmetic use at typical concentrations. It has low irritation and sensitization potential. No significant safety concerns have been raised by regulatory bodies.

Research notes

Limited peer-reviewed studies specifically on polyurethane-81, but the broader polyurethane family has been evaluated for cosmetic safety. Industry data supports its use as a low-irritant film former.

Common label clues

Typical concentration
0.5% to 5%
Regulatory status
Approved for use in cosmetics in the EU, US, and many other regions. No specific restrictions beyond general cosmetic safety requirements.
Common uses
Long-wear foundations, Waterproof mascaras, Styling gels, Sunscreens
Environmental note
As a synthetic polymer, it is not biodegradable. However, it is used in small amounts and typically removed during wastewater treatment.

Good to know

  • Polyurethane-81 is often combined with other film-formers to balance flexibility and hold.
  • It is considered non-comedogenic for most skin types, but patch test if you are prone to clogged pores.

Common questions

What is Polyurethane-81 in beauty products?

Polyurethane-81 is a man-made polymer that forms a thin, flexible film on your skin or hair. Think of it like a clear, breathable plastic wrap that helps makeup stay put or holds a hairstyle in place. It's water-resistant but not completely waterproof, and it washes off with regular cleansers or shampoo.

What does Polyurethane-81 do in a beauty product?

When applied, the polymer chains spread and link together as the solvent (water or alcohol) evaporates, forming a uniform, flexible film. This film physically locks in pigments or holds hair strands in shape, while still allowing some movement and moisture vapor to pass through.

Is Polyurethane-81 safe for most people?

Polyurethane-81 is considered safe for cosmetic use at typical concentrations. It has low irritation and sensitization potential. No significant safety concerns have been raised by regulatory bodies.

Who should be careful with Polyurethane-81?

Those with very dry or dehydrated skin who prefer lightweight, breathable formulas

Research sources

Cosmetic Ingredient Review (CIR) - Polyurethane SafetyOpenEuropean Chemicals Agency (ECHA) - Polyurethane-81OpenPubMed - Film-forming polymers in cosmeticsOpen

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.