Item: Sodium metabisulfite Appearance: white or light yellow crystal Molecular ... powder Character: with smell of SO2,soluble in water,the solution is acidic.Usages: Fiber, photo ,pharmacy,chemical ,petroleum ... Character: with smell of SO2,soluble in water,the solution is acidic.Usages: Fiber, photo ,pharmacy,chemical ,petroleum ... thiosulfate≤ %--Pb≤ %0.0010.0002As ≤ %0.00010.00003 Sodium metabisulfite