Science
Mechanism of Action
When applied to the skin, Sodium Silicate dries and contracts, creating a transient film that physically tightens the skin's surface. This mechanical action diminishes the look of fine lines, wrinkles, and pores. Beyond its aesthetic benefits, it helps regulate formula pH, absorbs excess facial oils for an oil-control effect, and contributes to product integrity as an emulsifier, thickener, and barrier former against moisture loss.
Research
Clinical Evidence
Medium confidence4%
Key findings
- 01 Formulations containing 5-10% of a 37.5% active sodium silicate solution (equating to 1.875-3.75% active ingredient) have been effectively utilized for temporary skin tightening, reducing the appearance of fine lines and wrinkles.
- 02 Active concentrations ranging from 2-6% have been historically employed in instant skin tighteners for their visible effects.
- 03 An active concentration of 4% (derived from 10% of a 40% aqueous solution) was found non-irritating in human repeat-insult patch tests and considered a mild irritant under normal use conditions in cumulative irritancy studies.
Transparency
Dusting Analysis
The Formula
Formulation
Stability
Sodium silicate solutions are inherently alkaline, typically presenting a pH range of 11-13 in commercial forms, with a 0.5% solution having a pH of approximately 12.5. This high alkalinity provides significant buffer capacity, essential for pH stabilization in cosmetic formulations. Low pH environments can accelerate the gelation process, and the ingredient is also susceptible to hydrolysis by hot water.
Conflicts
- Acids (leads to precipitation)
- Certain salts (e.g., potassium and sodium salts, resulting in insolubility or precipitation)
- Divalent ions (may impact gelation)
Safety
Safety Profile
The Cosmetic Ingredient Review (CIR) Expert Panel deems Sodium Silicate, along with Potassium Silicate and Sodium Metasilicate, safe for cosmetic use under conditions that prevent irritation, as described in their safety assessment. While generally considered safe by the FDA and EU, concentrated forms or low molar ratios of SiO2/Na2O can be strong irritants. Corrosivity has been reported at concentrations exceeding 50% with molar ratios up to 1.6, and irritation at molar ratios above 1.6. However, formulations with concentrations below 40% and molar ratios of SiO2/Na2O greater than 3.2 have shown no irritating effects on the skin. Its overall hazard rating is low (2 out of 10) in the Cosmetics Database.
Your Skin
Skin Compatibility
Our Assessment
Verdict
Sodium Silicate is a valuable ingredient for temporary skin tightening and pH regulation, requiring precise formulation to ensure efficacy and prevent potential irritation.
Related
Similar Ingredients
Finding similar ingredients…