... 99%min Package: 25kg/ bag Sodium Thiosulphate 99%, pentahydrateSodium thiosulfate (Na2S2O3), also spelled sodium thiosulphate, is a colorless crystalline compound ... 5H2O, an efflorescent, monoclinic crystalline substance also called sodium hyposulfite or “hypo.”Specification:Inspection Standard: HG/T ... interest. P&B white big crystals Sodium Thiosulphate(Sodium Hyposulfite),pentahydrate 99% purity