sodium metabisulfite

Molecular Formula:Na2S2O5 Molecule Weight:190.10 Appearance:White or light yellow crystalline powder Quality standard:GB19831998 The detailed specifications for INDUSTRY GRADE are the following: ITEM INDEX Content (such as Na2S2O5 97% min SO2 65% min Iron(Fe) 0.005% max Insuluble in water 0.05% max PH Value 4.0-4.6 Arsenic (AS) 0.0001%The detailed specifications for FOOD GRADE are the following:ITEM INDEX Content (such as Na2S2O5) 97%min SO2 65% min Insoluble in water 0.05% max PH Value 4.0-6.0 Arsenic(As) 0.0001% max Heavy metal (based on Pb) 0.001% maxMain uses: (1)Bleach agent (2)Loose agent (3)Antiseptic and germicide (4)Inhibitor and freshen agent