Preservatives
Sodium benzoate
Definition
What it is
Benzoate preservative: linked to hyperactivity in children; reacts with vitamin C (ascorbic acid) to form benzene, a known carcinogen, in soft drinks.
On the label
How it appears on labels
- sodium benzoate
Regulation
Regulatory status
No bans or restrictions are recorded for this ingredient in the jurisdictions clearlabel tracks (US, EU, UK, Canada, Japan, Australia/NZ, Brazil).
Explainer
In plain language
Sodium benzoate is a preservative that stops the growth of mold, yeast, and some bacteria, especially in acidic foods and drinks. It is the sodium salt of benzoic acid, which occurs naturally in some fruits, though the food additive is made synthetically. Its job is to keep sodas, dressings, and condiments stable on the shelf.
Assessment
Why it is flagged
Two issues put sodium benzoate on the list. First, the 2007 Southampton study published in The Lancet tested sodium benzoate alongside synthetic dyes and associated the mixture with increased hyperactivity in some children, though the study could not isolate the benzoate's individual role. Second, when sodium benzoate is present with vitamin C (ascorbic acid), the two can react to form benzene, a known carcinogen, particularly in soft drinks exposed to heat or light. The FDA studied benzene in soft drinks in the 2000s, most beverages measured low, and many manufacturers reformulated to prevent the reaction. Regulators in the US and EU permit sodium benzoate within set limits. Clear Label marks it medium severity because of the benzene chemistry and the hyperactivity signal, both of which are worth tracking in your own logs.
In the aisle
Where it commonly shows up
- Sodas and soft drinks
- Fruit juices and juice drinks
- Salad dressings and condiments
- Pickles and pickled products
- Jams, syrups, and sauces
- Some medicines and mouthwashes
Practical
Reading the label
US labels name it sodium benzoate; in the EU it is E211. The benzene concern is highest when a drink lists both sodium benzoate and ascorbic acid or vitamin C, so seeing those two together on a soda is the pattern to notice.
Alternatives
If you want to avoid it
Some people choose drinks and condiments preserved by refrigeration, canning, or acidity alone, or products that list neither sodium benzoate nor the benzoate-plus-vitamin-C combination. Comparing labels on two similar sodas often reveals which relies on it.
FAQ
Common questions
Does sodium benzoate form benzene in every drink?
No. Benzene can form when sodium benzoate and vitamin C are both present, especially with heat or light, but not all products contain that combination, and many were reformulated after the FDA's testing. Most beverages the FDA measured had low levels.
Is sodium benzoate linked to hyperactivity?
The 2007 Southampton study associated a mix of sodium benzoate and synthetic dyes with more hyperactivity in some children, but it could not separate benzoate's individual effect. Sensitivity appears to vary, which makes it a pattern to test rather than a settled harm.
Is sodium benzoate the same as potassium sorbate?
No, they are different preservatives, though both fight mold and yeast and are sometimes used together. Potassium sorbate does not carry the benzene concern that sodium benzoate does with vitamin C.
Citations
Sources
Citation
Primary reference
About this page: the definition, label names, severity, and regulatory chips come from the clearlabel ingredient taxonomy, the same data the scanner uses to score products. Research summaries describe associations reported in published studies, not diagnoses; individual responses vary. Scan any product with clearlabel to see which of its ingredients carry flags.