At a glance
- CAS number
- 532-32-1
- INCI name
- Sodium Benzoate
- Function
- preservative, ph_adjuster
- Typical use level
- 0.1%–0.5%
- Solubility
- water
- Stable pH
- 2.5–5.5
CAS number and synonyms are sourced from PubChem. Function, usage levels, pH and compatibility are AI-assisted formulation guidance — verify against your supplier's technical data sheet and applicable regulations before use.
Also known as
sodium benzoate Sobenate Antimol Benzoic acid, sodium salt sodium;benzoate Benzoate sodium Benzoate of soda Benzoate, sodium Natrium benzoicum FEMA No. 3025 Fuminaru Benzoan sodny
Compatibility
Works well with:
Potassium Sorbate Citric Acid Glycerin Niacinamide Allantoin Panthenol Xanthan Gum Carbomer
Use caution with:
L-Ascorbic Acid Vitamin C derivatives Quaternary Ammonium Compounds Cationic Surfactants Iron Salts
Sodium Benzoate reacts with Vitamin C (ascorbic acid) to form benzene, a known carcinogen, making this combination unsuitable for cosmetic formulations. Its preservative efficacy depends heavily on pH — it must be used below pH 5.5 as the active form is undissociated benzoic acid, which diminishes significantly above this range. Cationic ingredients can cause precipitation or reduce antimicrobial activity.
Formulation notes
EU Cosmetics Regulation restricts Sodium Benzoate to a maximum of 0.5% in leave-on and rinse-off products. Not recommended in products containing ascorbic acid. Most effective as a broad-spectrum preservative (bacteria/yeast/mold) in acidic formulations; often paired with Potassium Sorbate for enhanced spectrum coverage.
Related ingredients
- Benzyl AlcoholPreservative
- Caprylyl GlycolPreservative
- ChlorphenesinPreservative
- PhenoxyethanolPreservative
- Ascorbic AcidAntioxidant
- Glycolic AcidActive