Sodium Metabisulphite (Na2S2O5 98%) is an inorganic chemical reducing agent used as an antichlor in reverse osmosis water treatment, a cyanide destruction agent in gold mining leaching, and a preservative (E223) in food processing. Kiki's supplies 25kg bags and bulk quantities across Kenya.
Sodium Metabisulphite is a white crystalline inorganic salt consisting of sodium disulfite ions, valued for its rapid oxygen-scavenging, chlorine-neutralizing, and microbial preservation properties.
Key Facts
Primary Use Cases
Product Code: KIC-MIN-202
Also known as: Sodium Metabisulphite, Sodium Pyrosulfite, Sodium Disulfite, SMBS, E223
Synonyms: Disodium Disulfite, Pyrosulfurous Acid Sodium Salt, Sodium Metabisulfite (Na2S2O5)
High-purity Sodium Metabisulphite (Na2S2O5 98%) used as a powerful reducing agent, antichlor, oxygen scavenger in water treatment, wine/food preservative (E223), and cyanide destruction agent in gold mining leaching.
Available Packaging
Sodium Metabisulphite (Na2S2O5, CAS 7681-57-4), also known as sodium pyrosulfite or SMBS, is a white crystalline powder with a faint sulfur dioxide odour. It is an essential inorganic reducing agent widely utilized across East Africa in mining (cyanide neutralization), water treatment (dechlorination and RO membrane protection), food & beverage processing (E223 preservative and antioxidant), textile processing, and leather tanning.
In aqueous solution, Sodium Metabisulphite reacts with water to release bisulfite ions (HSO3-) and sulfur dioxide (SO2). This rapid reduction mechanism makes it ideal for neutralizing residual chlorine and chloramines in industrial water treatment prior to reverse osmosis (RO) filtration, preventing polyamide membrane oxidation. In gold leaching plants, SMBS is dissolved to supply SO2 for the INCO SO2/air cyanide destruction process, rapidly degrading free and WAD cyanides into less toxic cyanate ions.
Contact Kiki's sales engineering team for COA batch verification, bulk volume pricing, or technical dosing guidance.
Store in a cool, dry, well-ventilated warehouse away from direct sunlight, moisture, strong acids, and oxidizing agents. Keep containers tightly sealed in moisture-proof polyethylene-lined bags. Avoid temperatures above 50°C to prevent thermal decomposition and toxic sulfur dioxide gas evolution.
Wear full personal protective equipment including chemical splash goggles, half-mask respirator with sulfur dioxide/dust cartridges, nitrile gloves, and protective coveralls. Avoid dust generation and inhalation. In case of spills, sweep dry material into clean, labelled containers without creating airborne dust; neutralize residue with dilute sodium carbonate solution.
Eye contact: Immediately flush with running water for 15+ minutes holding eyelids open; seek urgent medical aid. Skin contact: Wash thoroughly with soap and water; remove contaminated clothes. Inhalation: Move victim to fresh air; administer oxygen if breathing is difficult. Ingestion: Rinse mouth with water; do NOT induce vomiting; seek immediate medical advice.
Hazard Statements
Precautionary Statements
PPE Requirements
COMMERCIAL & TECHNICAL GUIDANCE
Technical, regulatory, and supply guidance for Sodium Metabisulphite (SMBS / Sodium Pyrosulfite) 97–98% Technical & Food Grade.
Sodium Metabisulphite (SMBS) is used as a primary source of sulfur dioxide (SO2) in the INCO SO2/air cyanide destruction process. It oxidizes toxic free and WAD cyanides in gold leach tailings into environmentally safe cyanate ions prior to discharge into tailings storage facilities.
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