Sodium benzoate

Product Details

CasNo： 532-32-1

MF： C7H5NaO2

Appearance： powder

Delivery Time： 15 days

Packing： 25kg/bag

Purity： 99%

1. Basic Information

• English Name: Sodium Benzoate
• Chinese Name: 苯甲酸钠
• CAS Number: 532-32-1
• Molecular Formula: C₆H₅COONa (or C₇H₅O₂Na)
• Molecular Weight: 144.11 g/mol
• Chemical Structure: A salt formed by the combination of the carboxyl group (-COOH) of benzoic acid and sodium ions (Na⁺). Its molecular core consists of a benzene ring attached to a sodium carboxylate group (-COONa). Its antibacterial activity mainly comes from its ability to convert to benzoic acid (undissociated form) in acidic environments.
• Common Forms: Commercially available products are mostly white crystalline powder or granules, odorless or with a slight benzoin-like odor. They are hygroscopic but do not clump (high-purity products have lower hygroscopicity); a small number are high-concentration aqueous solutions (e.g., 30% solution) for special process scenarios.

2. Physical and Chemical Properties

3. Key Performance Characteristics

1. Broad-Spectrum Antibacterial Activity, Optimal in Acidic Environments
   The antibacterial mechanism of Sodium Benzoate is to penetrate microbial cell membranes, inhibit the activity of cellular respiratory enzymes and ATP synthetase, and ultimately lead to microbial death. Its core advantages are:

• Broad Antibacterial Spectrum: Effective against gram-positive bacteria (e.g., Staphylococcus aureus), gram-negative bacteria (e.g., E. coli), yeasts (e.g., Saccharomyces cerevisiae), and molds (e.g., Aspergillus niger). It is particularly effective in inhibiting "spoilage bacteria" common in food (e.g., lactic acid bacteria, acetic acid bacteria).
• Acidity-Dependent Property: It is only converted to benzoic acid (undissociated form) in large quantities in environments with pH < 4.5 to exert the best antibacterial activity. For example, in carbonated drinks and preserved fruits with pH 2.5–4.0, the minimum inhibitory concentration (MIC) can be as low as 0.05%–0.1%; when pH > 5.5, its activity decreases significantly, and it needs to be used in combination with other preservatives (e.g., potassium sorbate).

1. High Safety and Wide Regulatory Recognition

• Low Toxicity: The acute oral LD₅₀ (rat) is > 4000 mg/kg (classified as "practically non-toxic"), much higher than that of table salt (LD₅₀ ≈ 3000 mg/kg); the acceptable daily intake (ADI) for humans is 0–5 mg/kg body weight (FAO/WHO standard), with no health risks under regular use.
• Metabolic Friendliness: After entering the human body, more than 90% is converted to benzoic acid in the liver, then combined with glycine to form "hippuric acid", which is excreted through urine (half-life is only 2–4 hours). It does not accumulate in the body and has no chronic toxicity.

1. Strong Compatibility, No Impact on Product Sensory Properties

• No Conflict with Auxiliary Materials: It can coexist harmoniously with sugars, organic acids (citric acid, malic acid), vitamins, pigments, and surfactants in food without precipitation, discoloration, or odor generation. For example, adding 0.1% Sodium Benzoate to fruit juice does not change the color, sweetness, or fruity flavor of the juice.
• No Sensory Interference: It has no peculiar smell itself, and its addition does not affect the taste of food (e.g., the freshness of carbonated drinks), the skin feel of cosmetics (e.g., the moisturizing property of toners), or the palatability of pharmaceuticals, meeting the demand for "invisible preservation".

4. Main Application Fields

1. Food and Beverage Industry (Core Scenario)

2. Cosmetics and Personal Care Products

• Skincare Products (Toners, Lotions): Added at 0.1%–0.3% to inhibit microbial growth in formulations (especially products containing natural extracts), preventing skincare products from becoming odorous or stratified; combined with parabens, it can expand the antibacterial spectrum.
• Oral Care Products (Mouthwash, Toothpaste): Added at 0.05%–0.1% to inhibit oral pathogenic bacteria (e.g., Streptococcus mutans) and improve the taste of mouthwash (weak alkalinity can neutralize oral acidity).

3. Pharmaceutical and Industrial Fields

• Pharmaceuticals (Oral Liquids, Syrups): As a "pharmaceutical excipient" (included in the Chinese Pharmacopoeia CP2020 edition), it is added at 0.05%–0.2% to prevent microbial contamination of the liquid during storage and ensure medication safety.
• Industrial Rust Inhibitors: Added to metal cutting fluids (0.5%–1%) to inhibit bacterial reproduction that causes odor and deterioration of cutting fluids, while assisting in enhancing the rust-proof effect.

5. Safety and Storage Specifications

1. Safety Warnings (Low-Risk Characteristics)

Sodium Benzoate has extremely high safety and no GHS hazard classification (non-flammable, non-corrosive, no acute toxicity), but attention should be paid to:

• Avoid long-term and large-scale inhalation of powder (may cause slight respiratory irritation); it is recommended to wear a dust mask during operation.
• Although it has no irritation to the skin, sensitive people (e.g., asthmatics) should avoid direct contact with high-concentration powder.
• It cannot be used in infant formula food (specified in China's GB 2760 standard); for other foods, the "maximum usage amount" must be strictly followed to avoid excessive addition.

2. Regulatory Compliance

• Complies with international standards: Joint FAO/WHO Expert Committee on Food Additives (JECFA), US FDA (21 CFR §184.1733), EU Regulation EC No 1333/2008, allowing use in more than 180 countries worldwide.
• Complies with Chinese standards: National Food Safety Standard for the Use of Food Additives (GB 2760-2024), Cosmetic Safety Technical Specification (2024 Edition), and Chinese Pharmacopoeia (2020 Edition), which clearly specify the maximum usage amount in various fields (e.g., maximum 0.1% in food, maximum 0.5% in cosmetics).

3. Packaging and Storage

• Packaging Specifications:
  • Food-grade/Pharmaceutical-grade: 25 kg/bag (inner polyethylene film bag, outer kraft paper composite bag, moisture-proof and pollution-proof).
  • Industrial-grade: 50 kg/bag (polypropylene woven bag, lined with polyethylene film).
  • Small batches: 1 kg/aluminum foil bag (for laboratory or small-scale factory trials).
• Storage Conditions:
  • Store in a cool, dry, and well-ventilated place, with temperature controlled at 5–30°C and relative humidity < 75%. Avoid storing with strong oxidants and strong acids (e.g., hydrochloric acid).
  • After opening, the bag mouth must be sealed to prevent moisture absorption and caking (caking does not affect activity; it can be crushed and used normally).
  • Shelf life of unopened products: 24 months for food-grade, 18 months for industrial-grade.