Sodium Metabisulfite
Keeps the formula fresh.
What it is
A sulfite, a salt that contains sulfur, made in a lab.
An antioxidant that keeps other ingredients from reacting with oxygen, and it also works as a preservative.
What it does in a formula
Keeps the formula freshOfficial EU function: Preservative
Protects the formulaOfficial EU function: Antioxidant
ReducingOfficial EU function: Reducing
What official sources say
Restricted in certain uses · Cosmetics, EU
Allowed in EU cosmetics only within set limits and conditions (Annex III, entry 99).
Regulation (EC) No 1223/2009, Annex III: list of substances which cosmetic products must not contain except subject to the restrictions laid down (CosIng), retrieved 2026-10-09Restricted in certain uses · Cosmetics, EU
Allowed as a preservative in EU cosmetics up to 0.2% (Annex V).
Regulation (EC) No 1223/2009, Annex V: list of preservatives allowed in cosmetic products (CosIng), retrieved 2026-10-09