What Is Sodium Benzonate?

Sodium benzoate is a chemically neutral salt and is a common preservative in some foods. Though there has been some controversy about the substance's safety in the past, the Food and Drug Administration considers sodium benzoate as a generally recognized as safe, or GRAS, chemical for use in food products.

Chemistry

Manufacturers create sodium benzoate by adding sodium hydroxide or sodium bicarbonate solution to benzoic acid. The sodium bonds with the benzoic acid to create the neutral sodium benzoate. The compound also appears naturally in some fruits, such as prunes, plums, apples and cranberries, according to Alaska Pacific University environmental science professor Richard L. Myers.

Uses

As a preservative, manufacturers most commonly use sodium benzoate in fruit juices, soda and other acidic foods. Myers states that sodium benzoate is most effective in foods that have a pH lower than 4.5; and the lower the pH, the better sodium benzoate performs as a preservative. While the compound is less active as an antibacterial agent than benzoic acid, it is up to 200 times more soluble in water, thus making it preferable for manufacturers. Medically, injections of sodium benzoate can help control high levels of ammonia in your blood caused by urea cycle disorder.

Carcinogen Concern

Myers states that in the 1990s the FDA found that sodium benzoate can react with ascorbic acid, or vitamin C, to create benzene. Benzene is a carcinogen and this raised great concern due to the fact that sodium benzoate is common in drinks containing vitamin C. Subsequent analysis of soft drinks revealed that they contain either no benzene or at a level that is below the acceptable amount found in drinking water.

Toxicity

Sodium benzoate is a fairly non-toxic substance, though it may cause an allergic reaction or other mild side effects in some people. The Iowa State University chemistry department reports that sodium benzoate induces death in 50 percent of laboratory rabbits with an oral dose of 2 g per kilogram of bodyweight, and a 4070 mg per kilograms of bodyweight dose in rats. In a 1973 review of sodium benzoate for the FDA, Litton Bionetics, Inc. found no mutagenic effects associated with either oral or injected forms of sodium benzoate.