Benzoic Acid
No meaningful concern for most people; irritation is possible but rare.
Also written as: Benzenecarboxylic Acid · E210
What it is
Benzoic acid occurs naturally in cranberries, cinnamon and gum benzoin, and is also produced synthetically. It is the active antimicrobial form of the benzoate family, and it only works when the formula is acidic enough for the free acid to be present. In cosmetics it is often used alongside benzyl alcohol and dehydroacetic acid in preservative blends.
What it does well
Broad antimicrobial activity in acidic formulas with a strong food-safety record
It is one of the oldest food and cosmetic preservatives and its toxicology is very well characterised at the levels the EU permits.
Moderate evidence
Worth knowing
Non-allergic contact urticaria and mild stinging
Benzoic acid is a classic cause of short-lived redness or hives on direct contact, especially near the lips. The reaction is transient and not an immune allergy.
Matters most toPeople with reactive skin, particularly around the mouth and eyes.
Where the EU stands
Approved preservative (Annex V)
Permitted preservative: max 0.5% in leave-on products, 1.7% in oral products and 2.5% in rinse-off products, expressed as the acid.
Regulation (EC) No 1223/2009, Annex V entry 1 · source ↗
Sources (1)
Every link goes to the original: a journal, a PubMed record or an EU document.
- [1]Final report on the safety assessment of Benzyl Alcohol, Benzoic Acid, and Sodium Benzoate
International Journal of Toxicology (Cosmetic Ingredient Review) · 2001
The expert panel concluded benzoic acid and its sodium salt are safe for use in cosmetic products at the concentrations reviewed.
