Ingredient review

Dimer Dilinoleate/Ethylenediamine Copolymer Acetate

INCI: DIMER DILINOLEATE/ETHYLENEDIAMINE COPOLYMER ACETATE

A synthetic film-former that helps products stay put, but offers no active skincare benefit.

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In plain English

This is a man-made polymer that dries down to a thin, flexible film on your skin or hair. It's what makes some sunscreens water-resistant and helps mascara or foundation last longer without smudging. Think of it like a clear, invisible raincoat that holds the product in place.

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

Dimer Dilinoleate/Ethylenediamine Copolymer Acetate 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 Dimer Dilinoleate/Ethylenediamine Copolymer Acetate.
  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 created by reacting dimer dilinoleate (a fatty acid derivative) with ethylenediamine, then acetylating the result. It forms a flexible, non-tacky film when applied.

How it works

When applied, the solvent (usually water or alcohol) evaporates, leaving behind a continuous polymer film. This film physically blocks water and oil from disturbing the underlying product, enhancing wear time and water resistance.

Pros

Strong water resistance

Creates a durable barrier that keeps sunscreen and makeup intact during swimming, sweating, or humid conditions.

Flexible film

Unlike some stiff polymers, this one dries to a flexible film that moves with your skin, reducing cracking or flaking.

Cons and cautions

Can feel heavy

On very dry or sensitive skin, the film may feel tight or uncomfortable, especially if layered under multiple products.

Requires double cleansing

Because it's water-resistant, a simple water-based cleanser may not remove it fully; an oil-based cleanser or micellar water is often needed.

Best for

  • People who want long-wearing or waterproof makeup
  • Those who need water-resistant sunscreen for swimming or sweating

Use caution if

  • Individuals with very dry or sensitive skin who prefer lightweight, breathable formulas

Usage tips

Use an oil-based cleanser or micellar water to remove products containing this ingredient thoroughly.
If you have dry skin, apply a hydrating serum or moisturizer underneath to prevent any tight feeling from the film.

Safety summary

Considered safe for use in cosmetics at typical concentrations. Low irritation and comedogenic potential. No known systemic toxicity from topical application.

Research notes

Limited independent research on this specific polymer, but it is structurally similar to other film-forming copolymers that have been reviewed by the Cosmetic Ingredient Review (CIR) panel and found safe for cosmetic use.

Common label clues

Typical concentration
0.5% to 5%
Regulatory status
Approved for use in cosmetics in the EU, US, and other major markets. No known restrictions at typical use levels.
Common uses
Sunscreens, Waterproof mascara, Long-wear foundations, Hair styling products
Environmental note
As a synthetic polymer, it is not biodegradable. However, it is used in small amounts and is not considered a major environmental concern compared to microplastics.

Good to know

  • This ingredient is not absorbed into the skin; it stays on the surface as a film.
  • It is often used in combination with other film-formers to fine-tune texture and water resistance.

Common questions

What is Dimer Dilinoleate/Ethylenediamine Copolymer Acetate in beauty products?

This is a man-made polymer that dries down to a thin, flexible film on your skin or hair. It's what makes some sunscreens water-resistant and helps mascara or foundation last longer without smudging. Think of it like a clear, invisible raincoat that holds the product in place.

What does Dimer Dilinoleate/Ethylenediamine Copolymer Acetate do in a beauty product?

When applied, the solvent (usually water or alcohol) evaporates, leaving behind a continuous polymer film. This film physically blocks water and oil from disturbing the underlying product, enhancing wear time and water resistance.

Is Dimer Dilinoleate/Ethylenediamine Copolymer Acetate safe for most people?

Considered safe for use in cosmetics at typical concentrations. Low irritation and comedogenic potential. No known systemic toxicity from topical application.

Who should be careful with Dimer Dilinoleate/Ethylenediamine Copolymer Acetate?

Individuals with very dry or sensitive skin who prefer lightweight, breathable formulas

Research sources

Cosmetic Ingredient Review (CIR) - Safety Assessment of Film-Forming PolymersOpenEuropean Chemicals Agency (ECHA) - Dimer Dilinoleate/Ethylenediamine Copolymer AcetateOpenPubMed - Film-Forming Polymers in SunscreensOpen

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.