Sodium benzoate
[CAS# 532-32-1]

Identification

• Classification: API >> Synthetic anti-infective drugs >> Disinfectant antiseptic
• Name: Sodium benzoate
• Synonyms: Benzoic acid sodium salt
• Molecular Formula: C₇H₅NaO₂
• Molecular Weight: 144.10
• CAS Registry Number: 532-32-1
• EC Number: 208-534-8
• FEMA: 3025
• SMILES: C1=CC=C(C=C1)C(=O)[O-].[Na+]

Properties

• Solubility: Soluble (water, alcohol)
• Melting point: 300 °C
• Flash point: 100 °C

Safety Data

• Hazard Symbols: GHS07 Warning
• Risk Statements: H319
• Safety Statements: P264+P265-P280-P305+P351+P338-P337+P317

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Eye irritation	Eye Irrit.	2	H319
Skin sensitization	Skin Sens.	1	H317
Eye irritation	Eye Irrit.	2A	H319
Acute toxicity	Acute Tox.	4	H302
Serious eye damage	Eye Dam.	1	H318
Gases under pressure (liquid)	Press. Gas (Liq.)		H280
Skin irritation	Skin Irrit.	2	H315

Discovery and Applications

Sodium benzoate is a sodium salt of benzoic acid, a compound that has been known since ancient times. The discovery of sodium benzoate can be traced back to the isolation of benzoic acid from the plant resin of the benzoin tree in the early 19th century. In the 1860s, chemists began to synthesize sodium benzoate from benzoic acid and sodium hydroxide, making it more accessible for commercial use. Over the years, sodium benzoate has become widely used in various industries, particularly in food preservation, pharmaceuticals, and cosmetics.

One of the primary applications of sodium benzoate is as a food preservative. It is effective in preventing the growth of mold, yeast, and certain bacteria in acidic foods and beverages. The efficacy of sodium benzoate as a preservative is enhanced in environments with a pH of 4.5 or lower, which is typical for many fruit juices, pickles, and soft drinks. By inhibiting microbial growth, sodium benzoate helps extend the shelf life of these products, making it a valuable additive in the food industry.

In addition to its role in food preservation, sodium benzoate is used in the pharmaceutical industry. It acts as a preservative in liquid medications, ensuring their stability and safety over time. Sodium benzoate is also employed as a reagent in various chemical syntheses, particularly in the preparation of other benzoic acid derivatives. Its use in pharmaceutical formulations highlights its importance in ensuring the efficacy and longevity of medications.

Sodium benzoate also finds applications in the cosmetic and personal care industry. It is commonly included in skincare products, shampoos, and other formulations to inhibit the growth of microorganisms, thus enhancing product stability. Its mild nature makes it suitable for use in cosmetic products, where it helps maintain product quality and safety.

Another significant aspect of sodium benzoate is its use in research and industrial applications. It serves as a model compound in various studies related to the behavior of preservatives, including their mechanisms of action and effectiveness against different microbial strains. Additionally, sodium benzoate is involved in the synthesis of various chemicals, such as dyes and fragrances, contributing to its utility in the chemical industry.

Despite its widespread use, concerns about sodium benzoate have arisen due to its potential to form benzene, a known carcinogen, when combined with ascorbic acid (vitamin C) under certain conditions. Regulatory agencies monitor the levels of sodium benzoate in food products to ensure consumer safety. Overall, sodium benzoate remains a vital compound with diverse applications across multiple sectors, underscoring its importance in modern industry and research.

References

2020. A mixture of potassium sorbate and sodium benzoate improved fermentation quality of whole‐plant corn silage by shifting bacterial communities. Journal of Applied Microbiology, 129(5).
DOI: 10.1111/jam.14571

2016. Evaluation of Galleria mellonella larvae as an in vivo model for assessing the relative toxicity of food preservative agents. Cell Biology and Toxicology, 32(3).
DOI: 10.1007/s10565-016-9329-x

1998. Biodegradation of cyanides, cyanates and thiocyanates to ammonia and carbon dioxide by immobilized cells of Pseudomonas putida. Journal of Industrial Microbiology and Biotechnology, 20(1).
DOI: 10.1038/sj.jim.2900469