Excipient (pharmacologically inactive substance)
What is it?
Sodium benzoate has a chemical formula of C7H5NaO2. Sodium benzoate is an antimicrobial preservative and flavoring agent used in the food industry and a tablet and capsule lubricant used in the pharmaceutical manufacturing industry.
Sodium benzoate is synthesized by combining benzoic acid with sodium hydroxide. Sodium benzoate does not occur naturally, but when it is mixed with water it produces benzoic acid, which can be found naturally in certain fruits such as plums, cranberries and apples. In the food industry, sodium benzoate is used in foods with an acidic pH such as pickles and salad dressings, in carbonated beverages, and in some fruit juice products.
The U.S. Food and Drug Administration (FDA) specifies a maximum level of 0.1 percent of sodium benzoate in food and at this level sodium benzoate is generally recognized as safe by the FDA. Toxicity of any type would not typically occur until a human ate a diet that contained ninety times the amount specified by the FDA. These low levels are most likely used in the pharmaceutical industry, as well.
When sodium benzoate is combined with vitamin C, as in some soft drinks and other beverages, and exposed to elevated temperatures or light the cancer-causing chemical benzene may form. The Environmental Protection Agency (EPA) maximum benzene level is set at 5 parts per billion (ppb) for drinking water, as a quality standard. In 2005-2007, the FDA sampled various soft drinks and other beverages that contained both single sodium benzoate and combined sodium benzoate and vitamin C and found that the vast majority of these beverages fell below the maximum level. Those products that were above the upper limit have since been reformulated. However, the FDA did not test every beverage on the market. FDA believes that the results of the surveys indicate that the levels of benzene found in soft drinks do not pose a safety concern.