Sodium benzoate has the chemical formula NaC7H5O2; it is a widely used food preservative, but is also found in cosmetics, dyes, pharmaceuticals, industrial settings. It's used to stop the fermentation process in wines. It is bacteriostatic and fungistatic under acidic conditions. It is most widely used in acidic foods such as salad dressings (vinegar), carbonated soda drinks (carbonic acid), fruit pies, jams and fruit juices (citric acid), pickles (vinegar), and condiments i.e. relishes and sauerkraut. It is also used as a preservative in medicines and cosmetics. As a food additive, sodium benzoate has the E number E211.

Sodium benzoate combines with water to produce benzoic acid, which is the active form of the preservative. Benzoic acid is also found naturally in some fruits such as cranberries, plums and apples.

Besides its use as a preservative in food, sodium benzoate is used in cosmetic products like mouthwash, toothpaste, deodorant, lotion, and shampoo. This is usually done to keep bacteria from growing in the products. It's also used in medicinal syrups, ointments, and pills. Industrially, sodium benzoate acts as a corrosion inhibitor, and is used to keep many different types of metals from rusting. It's commonly used in metal cans containing liquid foods or household cleaners, manufacturing machinery that is exposed to moisture, and in vehicle engines.

FDA has studied sodium benzoate extensively and found that it is safe when consumed in amounts found in normal diets. It would take approximately 90 times the amount of sodium benzoate found in a typical diet before any problems might occur. Concentration as a preservative is limited by the FDA in the U.S. to 0.1% by weight for humans and animals. The International Programme on Chemical Safety found no adverse effects in humans at doses of 647–825 mg/kg of body weight per day.

Be aware that when combined with ascorbic acid it forms the chemical benzene, a suspected carcinogen.

Recent research shows that sodium benzoate may be beneficial as an add-on therapy (1 gram/day) in schizophrenia. Total PANSS scores dropped by 21% compared to placebo.

CAS #: 532-32-1
Origin: USA
Notes: Food Grade. FCC, NF, Kosher Certified. FDA Classified generally recognized as safe (GRAS)
Specifications are subject to change without notice.
* FDA Disclaimer

References
about.com
wikipedia
livestrong