Sodium Borate Decahydrate, commonly known as Borax Decahydrate or Sodium Tetraborate Decahydrate, is an inorganic compound used in a variety of cosmetic, medical, and industrial applications. Comprising boron, sodium, and water molecules, this versatile ingredient is valued for its buffering, emulsifying, and antimicrobial properties. It plays a significant role in stabilizing formulations and improving their overall performance, especially in skincare and personal care products.

Chemical Composition and Structure

Sodium Borate Decahydrate has the chemical formula Na₂B₄O₇·10H₂O.

• Core Components:

  • Sodium (Na⁺): Contributes to the solubility and stability of the compound.
  • Borate ions (B₄O₇²⁻): Provide buffering and antimicrobial properties.
  • Ten water molecules: Essential for its crystalline structure and hydration-related functions.

• Properties:

  • Mildly alkaline, acting as a buffering agent in formulations.
  • Exhibits mild antimicrobial activity, enhancing product preservation.

Physicochemical Properties

• Appearance: White crystalline powder or colorless crystals.
• Odor: Odorless.
• Solubility: Soluble in water; insoluble in organic solvents.
• pH: Alkaline in aqueous solutions (pH ~9.3 for a 1% solution).
• Stability: Stable under normal storage conditions; may lose water of crystallization upon prolonged exposure to heat.

Production Process

1. Extraction:

   • Naturally obtained from boron-containing mineral deposits such as tincal.

2. Refining:

   • The crude mineral is dissolved in water, filtered to remove impurities, and recrystallized to obtain Sodium Borate Decahydrate.

3. Drying and Packaging:

   • The product is dried to remove excess moisture and packed for industrial, cosmetic, or pharmaceutical use.

Applications

Medical Applications

• Topical Antiseptic: Used in diluted solutions for minor skin irritations and infections.
• Buffering Agent: Stabilizes pH in medical formulations to enhance compatibility and effectiveness.

Cosmetics

1. Buffering:

   • Maintains the desired pH in formulations such as creams, lotions, and cleansers.

2. Emulsification:

   • Enhances the stability and consistency of emulsions, ensuring even distribution of active ingredients.

3. Preservation:

   • Exhibits mild antimicrobial properties, contributing to product longevity.

4. Exfoliation:

   • Occasionally used in scrubs for its gentle abrasive properties.

Industrial Applications

• Found in detergents, glass, and ceramics for its alkalinity and stabilizing properties.
• Used as a flux in metallurgy and as a component in adhesives and sealants.

Environmental and Safety Considerations

• Biodegradability:

  • Sodium Borate Decahydrate is a naturally occurring mineral and does not accumulate in the environment when used responsibly.

• Safety Profile:

  • Safe for regulated cosmetic use in low concentrations.
  • May cause skin or eye irritation in high concentrations; should be handled with care.

• Sustainability:

  • Sourced from abundant natural reserves with minimal environmental impact when extracted responsibly.

Conclusion

Sodium Borate Decahydrate is a multifunctional ingredient with diverse applications in cosmetics, medical, and industrial products. Its buffering, emulsifying, and antimicrobial properties make it a valuable component in stabilizing and enhancing formulations. When used in regulated concentrations, it is safe, effective, and environmentally sustainable.

References__________________________________________________________________________

Yokoyama MT, Spence C, Hengemuehle SM, Whitehead TR, von Bernuth R, Cotta M. Sodium Tetraborate Decahydrate Treatment Reduces Hydrogen Sulfide and the Sulfate-Reducing Bacteria Population of Swine Manure. J Environ Qual. 2016 Nov;45(6):1838-1846. doi: 10.2134/jeq2016.06.0219.

Tanpichai S, Phoothong F, Boonmahitthisud A. Superabsorbent cellulose-based hydrogels cross-liked with borax. Sci Rep. 2022 May 26;12(1):8920. doi: 10.1038/s41598-022-12688-2. PMID: 35618796; PMCID: PMC9134984.

Mostashari, S., & Fayyaz, F. (2008). TG of a cotton fabric impregnated by sodium borate decahydrate (Na 2 B 4 O 7· 10H 2 O) as a flame-retardant. Journal of thermal analysis and calorimetry, 93(3), 933-936.

Abstract . The effect of sodium borate decahydrate as a nondurable treatment on the flammability of 100% cotton fabric (woven plain 150 g m−2) has been investigated in this paper. The laundered bone-dried massed samples were impregnated with suitable concentrations of sodium borate decahydrate. Each bunches of fabrics were dipped into individual aqueous solutions of the salt, followed by means of squeeze rolls and drying at 110°C. By using a ‘vertical flame spread test’ the optimum add-on values to impart flame-retardancy onto cotton fabric was determined to be as 4.24 g salt per 100 g fabric. The objective of this study is thermogravimetry (TG) investigation of pure cotton, treated one with the salt at its optimum efficiency. So that outcomes could be compared and commented, finally the results obtained are in favor of ‘Chemical action theory’, ‘Condensed phase retardation’, ‘Dust or wall effect theory’ and also ‘Gas dilution theory’.

Goel, N., Sinha, N., & Kumar, B. (2013). Growth and properties of sodium tetraborate decahydrate single crystals. Materials Research Bulletin, 48(4), 1632-1636.

Abstract. Sodium tetraborate decahydrate (Na2B4O7·10H2O) single crystals were grown from aqueous solution by slow solvent evaporation method and its functional groups have been confirmed by FTIR. Grown crystals were found to be hard in nature (n = 1.8). From optical studies band gap of the material was found to be 4.1 eV and PL emission peak was found at 340 nm which can be due to annihilation self trapped excitons present in borate crystals. Dielectric constant was found to increase with temperature up to 70 °C. Conductivity obeys Jonscher's power law as seen at different temperatures. Activation energy of the crystal was found to be 2.05 eV.