Food Grade: Mainly used as bleaching agent, bulking agent, antioxidant preservatives in food processing.
Tech Grade: Mainly used for producing medicine iodoform, vanillin photographic fixative, rubber solidifying agent, decolorizing agent of bleached fiber, leather treatment of leather making industry, etc.
Item |
Food Grade |
Tech Grade |
Sodium Metabisulfite (as SO2) |
65% Min |
65% Min |
Iron(Fe) |
0.003% Max |
0.005% Max |
Insoluble matter in water |
0.05% Max |
0.05% Max |
PH |
4.0-4.6 |
4.0-4.6 |
Heavy metal(as Pb) |
0.002% Max |
- |
Arsenic(As) |
0.0002% Max |
- |