Specification for Industry Grade and Food Grade:
Item Quality Index
Industry Grade Food Grade
Purity ( As Na2SO3) 96.0% min 98.0% min
Sodium sulphate ( SO4) 2.0% max 1.0% max
Chlorides ( As NaCL) 0.5% max 0.1% max
Arsenic ( As ) - 0.0002% max
Heavy metals ( As Pb ) - 0.0005% max
Iron (Fe) 0.005% max 0.002% max
Water insolubles 0.05% max 0.02% max
Item Quality Index
Industry Grade Food Grade
Purity ( As Na2SO3) 96.0% min 98.0% min
Sodium sulphate ( SO4) 2.0% max 1.0% max
Chlorides ( As NaCL) 0.5% max 0.1% max
Arsenic ( As ) - 0.0002% max
Heavy metals ( As Pb ) - 0.0005% max
Iron (Fe) 0.005% max 0.002% max
Water insolubles 0.05% max 0.02% max
Item |
Quality Index
|
|
Photo Grade
|
Pharmaceutical Grade
|
|
Purity ( As Na2SO3)
|
98.0% min
|
98.0% min
|
Sodium sulphate ( SO4 )
|
1.0% max
|
1.0% max
|
Chlorides ( As CL - )
|
0.05% max
|
0.05% max
|
Arsenic ( As )
|
0.0002% max
|
2ppm max
|
Lead ( As Pb)
|
0.0005% max
|
2ppm max
|
Iron (Fe)
|
0.001% max
|
5ppm max
|
Selenium ( Se)
|
0.0001% max
|
1ppm max
|
Zinc ( Zn)
|
0.0001% max
|
1ppm max
|
Copper ( Cu )
|
0.0001% max
|
0.1ppm max
|
Mercury ( Hg)
|
0.0001% max
|
0.1 ppm max
|