Sodium Benzoate

CAS Number:

532-32-1

Chemical / IUPAC Name:

Sodium benzoate is the sodium salt of benzoic acid

INCI Name:

Sodium Benzoate

EC Number:

208-534-8

Molecular Formula:

C7H5NaO2

Molecular Weight:

144.11 g/mol

Other Names:

Benzoic acid, sodium salt; Sodium salt of phenylcarboxylic acid; E211

Uses:

Sodium benzoate is the sodium salt of benzoic acid, appearing as a white, odorless, or nearly odorless, crystalline powder or granule . It is primarily used as an antimicrobial preservative and is one of the most common preservatives in the food, beverage, and personal care industries .

· Cosmetics & Personal Care: Widely used as a preservative and antimicrobial agent in shampoos, conditioners, lotions, creams, liquid soaps, and other water-based formulations. It is effective against bacteria, yeasts, and molds, particularly in acidic formulations (pH 2-5) .

· Food & Beverage Industry: Used as a food additive (E211) to preserve acidic foods and beverages such as soft drinks, fruit juices, jams, jellies, pickles, and salad dressings. It prevents spoilage by inhibiting the growth of microorganisms .

· Pharmaceuticals: Used as a preservative in liquid medicines, cough syrups, and other pharmaceutical preparations. It is also used as a corrosion inhibitor in some formulations .

· Industrial Applications: Used as a corrosion inhibitor in engine coolants and antifreeze, and as an additive in plastics and adhesives .

Origin

Sodium benzoate is a synthetic compound produced by the neutralization of benzoic acid with sodium hydroxide or sodium bicarbonate . Benzoic acid itself can be derived from natural sources (such as gum benzoin) but is primarily produced synthetically for commercial use.

What does Sodium Benzoate Powder do in a formulation?

• Preservative / Antimicrobial Agent: Inhibits the growth of bacteria, yeasts, and molds, extending the shelf life of products. Its effectiveness is optimal at acidic pH levels (2-5) .
• Corrosion Inhibitor: Helps prevent corrosion in metal parts, particularly in industrial fluids like antifreeze .
• Solubilizer: Can aid in the solubility of other ingredients in some formulations .

Safety Profile:

· General Hazard Classification: Generally recognized as safe (GRAS) for use in food . According to CLP/GHS regulations, some classifications exist with hazard statements H315 (Causes skin irritation) and H319 (Causes serious eye irritation), though high-purity grades for cosmetics and food are typically processed to minimize risks .

· Concentration Limits: Typically used at 0.1 – 1.0% in cosmetic and food formulations . The FDA limits its use in food to 0.1% .

· Irritation & Sensitization: Generally regarded as non-irritating and non-sensitizing at typical use concentrations. May cause mild irritation to eyes upon direct contact . In rare cases, it can cause contact urticaria or other allergic reactions .

· Benzene Formation Concern: Under certain conditions (in the presence of ascorbic acid/vitamin C and exposure to heat or light), sodium benzoate can form small amounts of benzene, a known carcinogen . This is a well-documented concern, particularly in beverages, and manufacturers formulate to avoid these conditions .

· Toxicity: Low acute toxicity. Oral LD50 (rat): 2,700 – 4,100 mg/kg .

· Metabolism: In the human body, it is metabolized in the liver to form hippuric acid, which is then excreted in urine .

· Regulatory Status: FDA approved as GRAS . EU approved as food additive E211 . Approved for use in cosmetics worldwide, with usage restrictions in some regions .

· Storage: Store in a cool, dry, well-ventilated area away from incompatible materials (strong oxidizing agents, strong acids) .

Technical profile: