Ingredient review

Potassium Dimethylolbutanoate Copolymer

INCI: POTASSIUM DIMETHYLOLBUTANOATE/CHDM/IPDI COPOLYMER

A synthetic polymer that helps makeup and sunscreen stay put longer by forming a flexible, water-resistant film.

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In plain English

This is a man-made ingredient that creates a thin, invisible film on your skin or hair. Think of it like a gentle, flexible glue that helps makeup last through sweat and humidity, or keeps your hair style in place without making it stiff or crunchy.

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

Potassium Dimethylolbutanoate 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.

  1. Step 1Start with the score, then check the irritation and clogging risk before judging Potassium Dimethylolbutanoate Copolymer.
  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 copolymer made from dimethylolbutanoic acid, cyclohexanedimethanol (CHDM), and isophorone diisocyanate (IPDI). It belongs to the polyurethane family and is designed to form a durable yet flexible film.

How it works

When applied, the water in the product evaporates, leaving behind a thin polymer film that adheres to the skin or hair. This film resists water and oil, helping other ingredients (like pigments or UV filters) stay in place longer.

Pros

Long-lasting wear

Helps makeup and sunscreen resist sweat, humidity, and water, so you need fewer touch-ups throughout the day.

Flexible feel

Unlike some stiff films, this polymer stays flexible, so skin and hair feel natural and not brittle or tight.

Cons and cautions

Synthetic origin

It is a lab-made ingredient, which may not align with a natural or minimalist skincare philosophy.

Removal can be tricky

Because it is water-resistant, you may need an oil-based or dual-phase cleanser to fully remove it, especially from eyes.

Best for

  • Anyone wanting long-wearing makeup
  • People who need water-resistant sunscreen
  • Those with oily skin who struggle with makeup fading

Use caution if

  • Those who prefer 100% natural or plant-based ingredients
  • Anyone with known sensitivity to polyurethane compounds (rare)

Usage tips

Use a gentle oil-based cleanser or micellar water to remove products containing this polymer.
Layer it in your routine after moisturizer but before makeup for best film-forming results.
If using in a sunscreen, apply evenly and allow to dry for a minute before sun exposure.

Safety summary

Potassium Dimethylolbutanoate/CHDM/IPDI Copolymer is considered safe for cosmetic use. It has low irritation and comedogenic potential. Rare allergic reactions are possible, but overall it is well-tolerated.

Research notes

Safety assessments by the Cosmetic Ingredient Review (CIR) and European Chemicals Agency (ECHA) support its use in cosmetics. Most data come from industry studies and regulatory reviews rather than independent clinical trials.

Common label clues

Typical concentration
0.5% to 5%
Regulatory status
Approved for use in cosmetics in the EU, USA, and many other regions. The Cosmetic Ingredient Review (CIR) panel has evaluated polyurethane copolymers and found them safe at typical use concentrations.
Common uses
Long-wear makeup, Water-resistant sunscreens, Styling products, Mascara
Environmental note
As a synthetic polymer, it is not biodegradable. However, it is used in low concentrations and is not known to bioaccumulate significantly.

Good to know

  • This polymer is often listed under the trade name 'Polyurethane-1' on ingredient labels.
  • It is considered safe for use in cosmetics by major regulatory bodies when used as intended.

Common questions

What is Potassium Dimethylolbutanoate Copolymer in beauty products?

This is a man-made ingredient that creates a thin, invisible film on your skin or hair. Think of it like a gentle, flexible glue that helps makeup last through sweat and humidity, or keeps your hair style in place without making it stiff or crunchy.

What does Potassium Dimethylolbutanoate Copolymer do in a beauty product?

When applied, the water in the product evaporates, leaving behind a thin polymer film that adheres to the skin or hair. This film resists water and oil, helping other ingredients (like pigments or UV filters) stay in place longer.

Is Potassium Dimethylolbutanoate Copolymer safe for most people?

Potassium Dimethylolbutanoate/CHDM/IPDI Copolymer is considered safe for cosmetic use. It has low irritation and comedogenic potential. Rare allergic reactions are possible, but overall it is well-tolerated.

Who should be careful with Potassium Dimethylolbutanoate Copolymer?

Those who prefer 100% natural or plant-based ingredients Anyone with known sensitivity to polyurethane compounds (rare)

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.