Sodium benzoate
Can form benzene with vitamin C; linked to hyperactivity in combination with dyes.
- Category
- Preservatives
- Acceptable daily intake
- 5 mg/kg body weight/day (EFSA)
- Vegan
- Yes
- Vegetarian
- Yes
What it is
Sodium benzoate (E211) is the sodium salt of benzoic acid. It is an extensively used preservative, particularly effective in acidic environments at preventing the growth of fungi, yeasts, and bacteria.
How it is used in food
Standard soluble preservative in soft drinks.
Commonly found in- Carbonated sodas and fruit juices
- Salad dressings and condiments
- Pickles
- Mouthwashes and cosmetics
Health and safety
Can form benzene with vitamin C; linked to hyperactivity when combined with azo dyes.
Sodium benzoate is considered safe in small quantities, but it is one of the more heavily scrutinized preservatives. Two main controversies surround it: its implication in childhood hyperactivity (when mixed with artificial colors), and its ability to form benzene (a known carcinogen) when combined with Vitamin C in acidic beverages.
Hyperactivity in children
The famous 2007 "Southampton Study" found that consuming sodium benzoate in combination with certain artificial food colors (the "Southampton Six") increased hyperactivity in children. While the EU requires warning labels for the colors, it does not mandate them for E211 on its own.
Benzene formation
When sodium benzoate (E211) is combined with ascorbic acid (Vitamin C, E300) in highly acidic beverages stored in warm conditions, they can react to form benzene, a known human carcinogen. Regulatory crackdowns have mostly forced manufacturers to reformulate products to avoid this combination.
The Southampton study linked it to hyperactivity effects in combination with certain dyes.
Regulatory status
| Region | Status | Notes |
|---|---|---|
| Australia & New Zealand FSANZ |
Permitted | Permitted. |
| European Union EFSA / European Commission |
Permitted | Authorised for food use under EU regulations (Annex II). |
| United States FDA (Food and Drug Administration) |
Permitted | GRAS, capped at 0.1% by weight in food. |
Identification on labels
- E-number
- E211
Also printed asBenzoate of soda
Alternatives to this additive
- E202: Potassium sorbate — A safer alternative that does not form benzene and is not linked to hyperactivity.
How it is made
While benzoic acid is found naturally in cranberries and apples, industrial sodium benzoate is produced synthetically by neutralizing benzoic acid (derived from petrochemicals) with sodium hydroxide.
- Synthesis of Benzoic Acid — Toluene (a petrochemical) is oxidized with oxygen to produce benzoic acid.
- Neutralization — The benzoic acid is reacted with sodium hydroxide.
- Crystallization — The resulting sodium benzoate is crystallized and dried.
Worth knowing
It is the soluble salt of benzoic acid.
Conclusion
E211 is a highly effective preservative for acidic foods, but clean-label trends are pushing manufacturers toward alternatives like potassium sorbate (E202) due to consumer concerns over hyperactivity and benzene formation.
References
- EFSA evaluation of E210 — EFSA
- EFSA re-evaluation of benzoic acid and benzoates — EFSA
- Southampton study (Lancet 2007) — The Lancet
- EFSA benzoates re-evaluation — EFSA
- Southampton Study on Food Colours and Hyperactivity — The Lancet
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