Sodium benzoate is a preservative found in a variety of foods, beverages and condiments. While it is generally recognized as safe in small doses, sodium benzoate may cause harmful health effects under certain conditions. Learning the facts on sodium benzoate allows you to assess its risks and benefits more accurately.
The most common source of sodium benzoate is food; manufacturers use it as a preservative to prevent spoilage. Acidic products like sauerkraut, jellies and jams, hot sauce and soda are the most common sources of sodium benzoate. Less commonly, sodium benzoate is used as a medication to treat hyperammonemia, a rare disorder that causes excess ammonia to accumulate in the blood. Traces of sodium benzoate are present naturally in some foods and seasonings, including cranberries, cinnamon, prunes and apples.
The amount of sodium benzoate in foods is so low it is unlikely to cause significant side effects in most people. After ingestion, it is absorbed rapidly and metabolized by the liver before being excreted by the kidneys. Sodium benzoate can trigger allergic reactions in some people, though. According to the December 2007 issue of "Environmental Health Perspectives" it has also been implicated as a potential trigger for hyperactivity in children with attention-deficit hyperactivity disorder. Sodium benzoate does in itself not cause the disorder, and more research is needed to determine what role, if any, it plays in worsening hyperactivity.
Benzene is a chemical that has been linked to increased risk of leukemia and other blood cancers. While sodium benzonate doesn't contain benzene, it can form benzene when combined with ascorbic acid. The Organic Consumers Association says benzene levels between two and 20 parts per billion have been found in some soft drinks containing sodium benzoate and ascorbic acid, also known as vitamin C. The safe level of benzene for drinking water is only five parts per billion, making the amounts of benzene in some soft drinks a health concern.
Despite its potential side effects, sodium benzoate has been determined safe for use in foods in amounts of up to 0.1 percent by weight. If you're concerned about the health risks of sodium benzoate, check food and drink labels before purchasing. To reduce the risk of benzene exposure, avoid buying soft drinks that list both ascorbic acid and sodium benzoate as ingredients.