Na2SO3 %

               ≥ 98.0 %

98.37%

Fe %

               ≤ 0.003%

                               0.003%

Water insoluble matter

               ≤ 0.02%

0.02%

Na2CO3

               ≤ 0.60%

0.23%

As

            2ppm max.

-

Pb

10ppm max.

<10 ppm