What Is Sodium Styrene/Acrylates/Peg-10 Dimaleate Copolymer?
Sodium Styrene/Acrylates/Peg-10 Dimaleate Copolymer is a synthetic polymer created by linking together small building blocks called monomers. These building blocks include styrene, acrylates, maleic acid and ethylene oxide units, which are then neutralized with sodium to make the final salt form used in cosmetics. The result is a large, flexible molecule that behaves a bit like a soft plastic film when it dries on the skin or hair.
The ingredient was introduced in the late 1990s as formulators looked for lightweight alternatives to older film formers that could feel sticky or heavy. Advances in polymer chemistry made it possible to combine styrene for strength, acrylates for flexibility and PEG segments for water compatibility, giving brands a single ingredient that delivers smooth even coverage.
Production starts with a water based reaction vessel where the monomers are gradually added and linked together under controlled heat and pH. Once the desired chain length is reached, the mixture is neutralized with sodium hydroxide, purified and dried into a fine powder or sold as a concentrated liquid dispersion. Because the process is water based it avoids the use of harsh organic solvents.
You are most likely to see this copolymer in products that need to create a thin even layer on the surface such as peel off masks, long wear foundations, tinted moisturizers, BB creams, liquid eyeliners, hair styling gels and some sunscreen lotions where it helps the formula resist sweat and light rubbing.
Sodium Styrene/Acrylates/Peg-10 Dimaleate Copolymer’s Cosmetic Benefits/Uses
This multifunctional polymer supports both the look and performance of many modern beauty formulas.
- Film Forming: It dries to form an invisible flexible film that locks pigments or active ingredients in place. This helps makeup last longer, keeps sunscreen evenly spread and gives hair gels their hold without flaking.
- Opacifying: By scattering light it reduces transparency in a formula, giving creams and gels a richer more luxurious appearance while also helping to blur minor skin imperfections when applied.
Who Can Use Sodium Styrene/Acrylates/Peg-10 Dimaleate Copolymer
This polymer is lightweight and inert so it generally suits all skin types including oily, combination, normal and dry skin. Sensitive skin usually tolerates it well because it has no active chemistry that would trigger stinging or burning, though very compromised or severely dehydrated skin might feel a slight tight film after it dries.
The ingredient is synthesized entirely from petrochemical and mineral sources with no animal-derived inputs, making it appropriate for vegans and vegetarians.
Because the molecule is large and stays on the surface experts consider it low risk for people who are pregnant or breastfeeding. That said this is not medical advice and anyone expecting or nursing should run any skincare choice past a qualified doctor just to be safe.
Sodium Styrene/Acrylates/Peg-10 Dimaleate Copolymer does not increase photosensitivity. In fact the film it forms can help sunscreens stay put and maintain their stated SPF.
It is also odorless gluten-free and generally regarded as safe for use around the eye area in eyeliners and mascaras.
Potential Side Effects/Adverse Reactions
Reactions to topical Sodium Styrene/Acrylates/Peg-10 Dimaleate Copolymer vary from person to person. The following list covers potential side effects but most users will not experience any of them when the ingredient is formulated and used correctly.
- Mild skin redness or itching in people with an existing sensitivity to synthetic polymers
- Transient tight or dry feeling if applied over very dehydrated skin without a moisturizer underneath
- Rare contact dermatitis when used in high concentrations or left on the skin for prolonged periods
- Eye irritation if loose powder or undiluted concentrate accidentally gets into the eyes
- Build-up on hair shafts that can make hair feel coated or dull if cleansing is inadequate
If you experience any discomfort swelling or persistent irritation discontinue use and consult a healthcare professional or dermatologist.
Comedogenic Rating
Rating: 1/5
Sodium Styrene/Acrylates/Peg-10 Dimaleate Copolymer sits on top of the skin as a breathable film and is too large to slip into pores, making it very unlikely to clog them. A small number of users may notice a coated feel if they layer several film formers without proper cleansing, which is why it does not receive a perfect zero.
Overall it is suitable for acne-prone skin because it rarely contributes to breakouts, especially when regular cleansing is part of the routine.
If you already struggle with heavy product build-up or use many long-wear formulas, double cleansing at night can prevent any residue-related congestion.
Summary
Sodium Styrene/Acrylates/Peg-10 Dimaleate Copolymer is valued for two key jobs: forming an even flexible film that locks makeup pigments or sunscreen actives in place and scattering light to give products a creamy opaque look while subtly blurring skin texture. It accomplishes this by linking styrene for strength, acrylates for flexibility and water-friendly PEG segments so the finished polymer spreads smoothly then dries into a soft mesh.
You will find it most often in long-wear foundations, peel-off masks, liquid eyeliners and some styling gels. It is not as famous as silicone elastomers or vinyl dimethicone copolymers, yet formulators like it because it offers good hold without a plasticky feel.
Safety reviews rate the polymer as low risk with minimal irritation potential. Still, every skin is different. When you pick up a new product that contains this copolymer, patch test on a small area for a couple of days before using it all over just to be sure it plays nicely with your skin.