A highly efficient synthetic polymer used primarily as a sequestering agent and rheology modifier. It prevents mineral buildup in formulations and ensures the uniform distribution of active ingredients across the skin surface.
- INCI Name:
- Sodium Acrylate/Maleic Acid Copolymer
- Chemical/Scientific Name:
- 2-Propenoic acid, polymer with 2-butenedioic acid, sodium salt
- Common Aliases:
- Sodium Acrylate/MA Copolymer, Acrylic Acid/Maleic Acid Copolymer Sodium Salt
| Category: | Stabilizers |
| Source Origin: | Synthetic |
| Comedogenic Rating: | 0 |
| Primary Industries: | Cosmetics, Industrial Cleaning, Water Treatment |
| Solubility: | Water-soluble |
At a Glance: Properties & Effects
| Formula Stability: | |
| Texture Enhancement: | |
| Irritation Risk: |
Primary Benefits:
- Prevents the precipitation of minerals in Aqua-based solutions.
- Enhances the long-term shelf life of complex emulsions.
- Supports the uniform application of pigments and UV filters.
Potential Risks:
- Low potential for skin irritation at standard cosmetic concentrations.
- Non-biodegradable, raising environmental considerations for rinse-off products.
Biological Action & Cosmetic Profile
Synthetic polymers of this class function predominantly through chelation and dispersion. By sequestering polyvalent cations such as calcium and magnesium, the molecule prevents these minerals from interacting with other components like surfactants or fatty acids. This mechanism ensures that the cosmetic remains clear and stable even when formulated with hard water.Chemically, the copolymer structure provides excellent anti-redeposition properties. While often utilized in laundry detergents to keep soil from re-attaching to fabrics, in skincare, this trait translates to a more uniform film on the skin. This film-forming capability can indirectly support the skin barrier, though it does not provide biological lipids like Ceramide Np.Viscosity control is another critical function of this ingredient. It helps manage the flow characteristics of gels and lotions, ensuring they do not become too runny or too thick over time. Because it is highly compatible with electrolytes, it remains effective in formulas containing salts or minerals where traditional thickeners like Carbomer might fail.
Broader Applications & Origins
The synthesis of this ingredient involves the free-radical polymerization of acrylic acid and maleic anhydride, followed by neutralization with Sodium Hydroxide. This process creates a water-soluble salt that is highly stable across a wide pH range. Beyond skincare, its ability to inhibit scale formation makes it a staple in industrial water treatment and high-performance detergent manufacturing.
Routine Integration
Synergies:
- Works effectively alongside humectants like Glycerin to maintain a smooth application feel.
- Complements preservatives such as Phenoxyethanol by ensuring the physical environment of the formula remains stable for antimicrobial activity.
- Pairs well with mineral-based sunscreens containing Titanium Dioxide to help keep particles dispersed.
Clinical Consensus & Safety
Dermatological safety evaluations, including those conducted by the Cosmetic Ingredient Review (CIR) Expert Panel, generally conclude that acrylate copolymers are safe for use in cosmetic products. Due to their large molecular weight, these polymers cannot penetrate the skin barrier, significantly minimizing the risk of systemic toxicity or internal irritation. Clinical data indicates that they are non-sensitizing and non-irritating when used in the concentrations typically found in leave-on and rinse-off skincare.
Is Sodium Acrylate/Maleic Acid Copolymer safe for sensitive skin?
Yes, this ingredient is considered safe for sensitive skin because its large molecular structure prevents it from being absorbed into the skin, thereby avoiding the biological pathways that trigger irritation.
Why is this ingredient in my serum?
It is likely included to act as a stabilizer, ensuring that the texture remains consistent and that minerals in the water do not cause the formula to separate or become cloudy.
Is this a microplastic?
While it is a synthetic polymer, its classification as a microplastic depends on specific regional regulatory definitions. In most cosmetic contexts, it is used in a liquid or dissolved state, which differs from the solid plastic beads often targeted by microplastic bans.