Ingredient review
Sodium Olefin/Maleic Acid Copolymer
INCI: SODIUM C4-12 OLEFIN/MALEIC ACID COPOLYMER
A synthetic polymer that helps products stay put on skin or hair, but offers no active skincare benefits.
In plain English
This is a man-made ingredient that forms a thin, invisible film on your skin or hair. Think of it like a clear, flexible coating that helps other ingredients stay in place, resist water, and feel smooth. It's commonly found in sunscreens to help them stay effective when you sweat or swim, and in makeup to keep it from smudging.
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
Sodium Olefin/Maleic Acid 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.
- Step 1Start with the score, then check the irritation and clogging risk before judging Sodium Olefin/Maleic Acid Copolymer.
- 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
A synthetic copolymer created by reacting C4-12 olefins (a group of hydrocarbon molecules) with maleic acid, then neutralizing with sodium. It is a water-soluble polymer that dries to a flexible, non-sticky film.
How it works
When applied, the polymer molecules spread out and link together as the water evaporates, forming a continuous film. This film acts as a barrier that can hold other ingredients (like UV filters or pigments) in place, resist water wash-off, and improve the overall feel of the product on the skin.
Pros
Enhances water resistance
Helps sunscreens and makeup stay effective even when you sweat or get wet, so you don't have to reapply as often.
Improves product feel
Creates a smooth, even film that makes creams and lotions feel silky and non-greasy on the skin.
Cons and cautions
Synthetic and non-biodegradable
As a synthetic polymer, it may not break down easily in the environment, which is a concern for eco-conscious consumers.
No active skincare benefit
It only improves texture and wear—it doesn't moisturize, soothe, or protect skin from aging or irritation.
Best for
- Anyone using water-resistant sunscreen or long-wear makeup
- People with oily skin who want makeup to stay put
Use caution if
- Those seeking only natural or plant-based ingredients
- Individuals with very sensitive skin who prefer minimal ingredient lists
Usage tips
Safety summary
Sodium C4-12 Olefin/Maleic Acid Copolymer is considered safe for use in cosmetics at typical concentrations. It has low irritation and comedogenic potential, making it suitable for most skin types. However, it is a synthetic ingredient and may not be preferred by those seeking natural formulations.
Research notes
Safety assessments by the Cosmetic Ingredient Review (CIR) panel and other bodies have found this type of copolymer to be safe for topical use. Studies focus on its film-forming properties rather than active biological effects.
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 specific concentration limits are set, but it is generally used at low levels.
- Common uses
- Sunscreens, Foundations, Waterproof mascaras, Hair styling products
- Environmental note
- As a synthetic polymer, it is not readily biodegradable. However, it is used in small amounts and is not known to accumulate in the environment at concerning levels.
Good to know
- This ingredient is often combined with other film-formers to boost water resistance even further.
- It is considered safe for use in cosmetics by major regulatory bodies when used as intended.
Common questions
What is Sodium Olefin/Maleic Acid Copolymer in beauty products?
This is a man-made ingredient that forms a thin, invisible film on your skin or hair. Think of it like a clear, flexible coating that helps other ingredients stay in place, resist water, and feel smooth. It's commonly found in sunscreens to help them stay effective when you sweat or swim, and in makeup to keep it from smudging.
What does Sodium Olefin/Maleic Acid Copolymer do in a beauty product?
When applied, the polymer molecules spread out and link together as the water evaporates, forming a continuous film. This film acts as a barrier that can hold other ingredients (like UV filters or pigments) in place, resist water wash-off, and improve the overall feel of the product on the skin.
Is Sodium Olefin/Maleic Acid Copolymer safe for most people?
Sodium C4-12 Olefin/Maleic Acid Copolymer is considered safe for use in cosmetics at typical concentrations. It has low irritation and comedogenic potential, making it suitable for most skin types. However, it is a synthetic ingredient and may not be preferred by those seeking natural formulations.
Who should be careful with Sodium Olefin/Maleic Acid Copolymer?
Those seeking only natural or plant-based ingredients Individuals with very sensitive skin who prefer minimal ingredient lists
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.