OriginPotassium metabisulfite is synthesized from potassium sulfite and sulfur dioxide, belonging to the inorganic sulfite chemical family. It is produced through the reaction of potassium carbonate or potassium hydroxide with sulfur dioxide gas.
Potassium metabisulfite appears as a white granular or powdery solid with a sharp odor of sulfur dioxide. Decomposes at 150 to 190 °C. Density 2.3 g / cm3. Contact severely irritates skin, eyes, and mucous membranes. Low toxicity. Used as a food preservative and an antioxidant.
Solubility Freely soluble in water; insoluble in alcohol
Formula
K2O5S2
Mol. Weight
222.33
CAS #
16731-55-8, 4429-42-9
Form
Powder
State
Potassium metabisulfite appears as a white granular or powdery solid with a sharp odor of sulfur dioxide. Decomposes at 150 to 190 °C. Density 2.3 g / cm3. Contact severely irritates skin, eyes, and m
Skin Types
●all-skin-types
Best For
General
Pregnancy & Breastfeeding Safe
Caution
Functions
Hair Waving Or Straightening
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
The paper trail
🔬Peer-reviewed1 paper →
⚖️Regulatory1 listing →
🛡️Safety-assessed2 reviews →
Counts, not a verdict. A listing isn't a study. The trail, you decide.
EWG
4
CIR
Safe as used
Pregnancy
Caution
Concentration Guide
Leave-onNot reported
Rinse-off0.35%
0%50%100%
Reg. limit 0.2%
CIR reported use · 2019 survey
EU regulatory limit: 0.2%. SO2) Source: EU Cosmetics Regulation (EC) 1223/2009, Annex V (Preservatives), Entry 9.
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