Sodium benzoate is a synthetic chemical produced when benzoic acid, which is found naturally in some fruits and spices, is combined with sodium hydroxide. Since sodium benzoate contains a natural ingredient, it is probably safe, right? After all, the US Food and Drug Administration (FDA) and the Canadian Health Protection Branch have pronounced this chemical preservative to be acceptable when consumed in low amounts.

In fact, the FDA has granted sodium benzoate GRAS (Generally Recognized as Safe) status, and the so-called safe limit in food is 0.1 percent by weight. In water, the acceptable limit, set by the Environmental Protection Agency, is 5 parts per billion (ppb). But this common food additive, which is found in carbonated sodas, fruit juice products, salad dressings, and fermented foods such as vinegar, wine, and pickles, is not natural nor safe. Here’s the story.

Sodium benzoate is a sodium salt that is present at extremely low levels in berries, apples, plums, cinnamon, and several other natural foods. There’s nothing scary about the chemical in these items. But lab-synthesized sodium benzoate (and its close relative, benzoic acid) are a different story. When these preservatives are added to foods and to the interior of metal cans that contain beverages or liquid foods, they can have a detrimental effect on your health.

For example, a small percentage of people are hypersensitive to sodium benzoate and can experience asthmatic attacks, hives, or other allergic reactions when they consume the preservative. A more common problem, however, is the combination of sodium benzoate and citric acid and/or ascorbic acid (vitamin C). When these ingredients get together, they form benzene, a cancer-causing chemical associated with leukemia and other blood cancers. 

During 2005 to 2007, the FDA conducted a study of various carbonated and fruit beverages that contained sodium benzoate alone and the preservatives along with vitamin C. At that time, they reported that most of the beverages contained less than the maximum allowable amount of sodium benzoate. Those that failed the test were reformulated. However, that does not mean every soft drink or fruit beverage on the market has been tested, nor that products in today’s market would meet the standards.

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Another consideration is a possible link between sodium benzoate and ADHD (attention deficit/hyperactivity disorder). The Mayo Clinic notes that the preservative (as well as several food dyes) may enhance or trigger hyperactivity in children.

In a laboratory study, scientists evaluated the genotoxic impact of sodium benzoate in cultured human cells. They found that the chemical significantly increased damage to DNA (which triggers cell mutation and cancer) when it was added to the cells in various concentrations.

Other exposures to sodium benzoate:

Manufacturers add sodium benzoate to health and beauty products such as mouthwash, shampoo, body lotions, and deodorant to prevent bacteria from contaminating these items. Over-the-counter and prescription drugs such as pills, cough syrups, and topical medications also can contain sodium benzoate.

What you should do:

If you want to avoid sodium benzoate, read labels carefully. Look for the words “benzoic acid,” “benzene,” “sodium benzoate,” or “benzoate,” especially if you also see “citric acid,” “ascorbic acid,” or “vitamin C.” Sodium benzoate is also known as E211.

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The next time you are in a supermarket and have a few minutes, check out the soft drink aisle. A quick peruse of the labels will reveal that some products (e.g., Coke Zero, Sprite) do not contain sodium benzoate and that others (e.g., Dr. Pepper, Sunkist Orange, Mountain Dew) do.

Since soft drinks and processed fruit drinks are typically the most common sources of sodium benzoate in the diet, you and your children can go a long way toward eliminating this chemical from your life if you stop consuming these beverages.