Sodium Metabisulfite

AKA “7681-57-4, Sodium pyrosulfite, Sodium disulfite, Disodium pyrosulfite, Natrii disulfis, Campden Tablets, Disodium metabisulfite, Natrium pyrosulfit, Natriummetabisulfit”

Preservative

Ingredient Facts

Sodium metabisulfite

AKA: 7681-57-4, Sodium pyrosulfite, Sodium disulfite, Disodium pyrosulfite, Natrii disulfis, Campden Tablets, Disodium metabisulfite, Natrium pyrosulfit, Natriummetabisulfit

Preservative · Antioxidant · EWG: 6

Synthetic

Antioxidant

Preservative

Medicated Active

Not Clean

Sodium metabisulfite appears as a white crystalline or powder solid with a slight sulfur odor. Toxic by inhalation. Strongly irritates skin and tissue. Noncombustible, but may decompose to emit toxic oxide fumes of sulfur and sodium when heated to high temperature. A corrosive acid when mixed with water. Used as a food preservative and as a laboratory reagent.

Solubility 54 % (NIOSH, 2024)

Formula

Na2O5S2

Mol. Weight

190.11

CAS #

7681-57-4, 7757-74-6

Form

Powder

State

Sodium metabisulfite appears as a white crystalline or powder solid with a slight sulfur odor. Toxic by inhalation. Strongly irritates skin and tissue. Noncombustible, but may decompose to emit toxic

See origin →

Functions

Antioxidant

Fights free radicals — the unstable molecules from UV, pollution, and stress that break down collagen and cause premature aging.

Preservative

Keeps your product from growing bacteria, mold, or yeast. Without these, that jar of cream becomes a petri dish in about a week.

Reducing

Neutralizes Free Radicals

Traditional Use

Developed in the 19th century as a preservative and antioxidant, first used industrially before being adopted in cosmetics in the mid-20th century to prevent oxidation and microbial growth in skincare products.