Sodium Benzoate
Granular
Technical / Cosmetic Grade
Sodium benzoate is the sodium salt of benzoic acid. It is a white granular powder that is soluble in water. It is bacteriostatic and fungicidal under acidic conditions. Sodium benzoate is used as a preservative in soaps, pharmaceuticals and cosmetics. It inhibits the growth of bacteria, yeast, and fungi.
Chemical Information
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Chemical formula: C₆H₅COONa
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Molar mass: 144.11 g/mol
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CAS number: 532-32-1
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Appearance: White, granules
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Solubility: Highly soluble in water 62.78 g/100 mL (15 °C)
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pH stability: Most effective in acidic conditions (pH < 6)
- Melting Point: 410 °C
Main Uses Of Sodium Benzoate
Cosmetics & Personal Care
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Preserves water-based formulations like:
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Shampoos, conditioners
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Body washes and lotions
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Facial cleansers and toners
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Often used in combination with potassium sorbate or other mild preservatives
Pharmaceuticals
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Used inTopical creams
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Functions both as a preservative and stabilizer
Industrial Applications
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Corrosion inhibitor in automotive coolants
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Used in some adhesives and lubricants to preserve shelf life
Summary
| Property | Detail |
|---|---|
| Function | Antimicrobial preservative |
| Effective pH range | Best below pH 6 |
| Applications | cosmetics, pharma, industry |
| Solubility | Water-soluble |
| Safety | Widely accepted in regulated limits |
PLEASE NOTE: This product is not for human or animal consumption.
Click here for Specification sheet
Formulation Tip: Using Sodium Benzoate
Example: Aqueous-Based Cosmetic (e.g., Facial Toner)
Goal: Preserve a water-based cosmetic with pH ~5.0
Preservative System
Sodium benzoate – 0.2%
Potassium sorbate – 0.2%
Citric acid – adjust pH to 4.5–5.2
Procedure
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Dissolve sodium benzoate and potassium sorbate into the water phase.
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Adjust pH using citric acid to ensure both preservatives are active (benzoate needs pH < 6.5, sorbate best below pH 5.5).
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Add other ingredients as needed (humectants, extracts, etc.).
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Perform microbial challenge testing for shelf stability.
This system is mild, paraben-free, and ideal for sensitive-skin formulations.
Use Tips
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Sodium benzoate works best in acidic formulations, making it ideal for facial mists, toners, micellar waters, and acidic gels.
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For more neutral pH or emulsions, pair with phenoxyethanol + ethylhexylglycerin or similar blends.
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Always test for microbial preservation effectiveness (challenge test or PET test).
Comparison Table: Common Preservatives
| Property | Sodium Benzoate | Potassium Sorbate | Phenoxyethanol |
|---|---|---|---|
| Effective pH | ≤ 6.5 (best at ≤ 5.5) | ≤ 5.5 | 3–10 |
| Spectrum | Yeast, fungi, some bacteria | Yeast, molds | Broad-spectrum (bacteria) |
| Typical use rate | 0.1–0.5% | 0.1–0.3% | 0.5–1.0% |
| Water solubility | High | Moderate | Low |
| Regulatory | cosmetic safe | cosmetic safe | EU/US approved, max 1% |
| Sensory impact | Neutral at low dose | Slight tang if overused | Slight rose/ether scent |
| Compatibility | Good with acids | Good with acids |
Soluble in glycols |