Sodium benzoate is a food preservative classified under the international numbering system as E211. Its chemical formula is C₆H₅COONa — the sodium salt of benzoic acid. As a preservative, sodium benzoate slows down microbial spoilage and extends the shelf life of food products.
Applications and dosage
Sodium benzoate is permitted for use in a wide range of food products (dosages expressed as benzoic acid equivalent, conversion factor 1.18):
- Soft drinks — up to 1,180 mg/L
- Low-alcohol beverages (below 15% ABV) and wines — up to 1,180 mg/L
- Preserved seafood (fish roe, fish, fish preserves) — 1,180–2,360 mg/kg or mg/L
- Fruit butter, fruit purée, dried fruits — up to 826 mg/kg
- Margarine and sauces — 1,180–2,360 mg/kg
- Yeast
Physical and chemical properties
Sodium benzoate appears as a white or off-white crystalline powder. Melting point: 300 °C. It is highly soluble in water, which makes it convenient for use in liquid and semi-liquid food products. In acidic environments (pH below 4.5), it is most effective as an antimicrobial agent, inhibiting the growth of yeasts, molds, and many bacteria.
Safety considerations
According to international safety classifications, sodium benzoate requires safety measures S24/25 — avoid contact with skin and eyes when handling the pure substance. Some preliminary studies suggest that frequent exposure may stimulate allergic reactions. When combined with ascorbic acid (vitamin C) under certain conditions, sodium benzoate can form trace amounts of benzene, a known carcinogen — though the levels typically found in food products are considered very low.
Find more information about food additives and preservatives in the articles below.