Science
Mechanism of Action
This polymer primarily acts as a humectant, significantly boosting skin hydration by drawing moisture from the environment and retaining it. It also serves as an efficient thickening agent, imparting a smooth, luxurious consistency to formulations and ensuring emulsion stability. Furthermore, Polyacrylic Acid exhibits film-forming capabilities, creating an imperceptible barrier on the skin that helps lock in moisture. When neutralized, it swells remarkably in water to form viscous gels and solutions, and is capable of stabilizing pH levels within cosmetic products.
Research
Clinical Evidence
Medium confidenceN/A
Transparency
Dusting Analysis
Polyacrylic Acid is primarily used as a functional ingredient for formulation properties rather than a direct skin active that would be 'dusted' in high concentrations.
The Formula
Formulation
Stability
Polyacrylic Acid performs optimally when neutralized, functioning effectively within a pH range of 5.0-9.0, though its unneutralized form has an approximate pH of 3. Aqueous gels can be sterilized via autoclaving or gamma irradiation, with the latter potentially increasing viscosity. To improve light stability, the addition of water-soluble UV absorbers (e.g., benzophenone-2 or -4) and edetic acid is advised. Unpreserved aqueous dispersions require an antimicrobial preservative to prevent microbial growth.
Conflicts
- Phenol
- Cationic polymers
- Strong acids
- High levels of electrolytes
- Resorcinol (can cause discoloration)
- Certain antimicrobial adjuvants (e.g., high concentrations of benzalkonium chloride or sodium benzoate may reduce viscosity and cause cloudiness)
- Trace levels of iron and other transition metals (can catalytically degrade dispersions)
- Certain amino-functional actives (form complexes)
- Certain polymeric excipients (form pH-dependent complexes)
- Chlorhexidine gluconate (may inactivate)
Safety
Safety Profile
The Cosmetic Ingredient Review (CIR) Expert Panel has deemed Polyacrylic Acid safe for cosmetic applications when formulated to be non-irritating. Its large molecular size significantly limits skin penetration, contributing to its low hazard rating (typically 1-2) by EWG, with minimal concerns for irritation or sensitization. The FDA also authorizes Poly(acrylic acid) for specific indirect food additive uses, and compliant grades are formulated to minimize residual impurities.
Your Skin
Skin Compatibility
Our Assessment
Verdict
Polyacrylic Acid is a valuable, multifunctional ingredient that enhances product texture and stability while contributing to skin hydration and a smooth feel, supported by a strong safety profile and broad compatibility across skin types.
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