Potassium Metabisulphite in Crystalline Powder Form is extensively used in photography and food preservative industries. Potassium Metabisulphite is available in white crystalline powder with a faint odour of sulphur dioxide gas. Potassium Metabisulphite contains assay in a minimum range of 95 %. Potassium Metabisulphite in Crystalline Powder Form is free from extraneous matter.