The ingredient narratives reshaping clean beauty.
Sodium Benzoate
aka benzoic acid sodium salt · E211 · benzoate
A widely used preservative in aqueous cosmetics and food. Effective against bacteria and yeast at acidic pH. Works synergistically with potassium sorbate for COSMOS-compatible broad-spectrum preservation.
- Broad-spectrum antimicrobial at pH <5.5
- COSMOS-certified preservative option
- Food-grade safety record
- Synergistic with potassium sorbate
- Effective against gram-negative bacteria at low pH
- Brightening serums (avoid with high-concentration L-ascorbic acid without metal chelation)
- Natural certified skin care
- K-beauty toners
- Aqueous serums
- Botanical mists
Most effective below pH 5.5. Above pH 6, the benzoate anion (less active form) predominates. Requires potassium sorbate pairing for full spectrum in COSMOS-compliant formulations. Incompatible with formulations using iron or heavy metal co-ingredients (benzoate chelation).
Reacts with ascorbic acid (vitamin C) in the presence of transition metals to form benzene — a carcinogen. This reaction is concentration and condition-dependent and rarely clinically relevant in cosmetics at typical use levels, but formulations combining sodium benzoate and vitamin C should minimise transition metal co-contamination.
Accepted in natural and COSMOS-certified formulations. EWG rating 1. One of the most widely used natural-compatible preservatives.
The ingredient narratives reshaping clean beauty.
Sodium Benzoate
aka benzoic acid sodium salt · E211 · benzoate
A widely used preservative in aqueous cosmetics and food. Effective against bacteria and yeast at acidic pH. Works synergistically with potassium sorbate for COSMOS-compatible broad-spectrum preservation.
- Broad-spectrum antimicrobial at pH <5.5
- COSMOS-certified preservative option
- Food-grade safety record
- Synergistic with potassium sorbate
- Effective against gram-negative bacteria at low pH
- Brightening serums (avoid with high-concentration L-ascorbic acid without metal chelation)
- Natural certified skin care
- K-beauty toners
- Aqueous serums
- Botanical mists
Most effective below pH 5.5. Above pH 6, the benzoate anion (less active form) predominates. Requires potassium sorbate pairing for full spectrum in COSMOS-compliant formulations. Incompatible with formulations using iron or heavy metal co-ingredients (benzoate chelation).
Reacts with ascorbic acid (vitamin C) in the presence of transition metals to form benzene — a carcinogen. This reaction is concentration and condition-dependent and rarely clinically relevant in cosmetics at typical use levels, but formulations combining sodium benzoate and vitamin C should minimise transition metal co-contamination.
Accepted in natural and COSMOS-certified formulations. EWG rating 1. One of the most widely used natural-compatible preservatives.