Index

I

II

III

Sodium Hydrosulphite

90% min

88% min

85% min

Water insoluble

0.1% max

0.1% max

0.1% max

Sodium thiosulfate: Na₂S₂O₃

1.2 % max

0.8% max

1.2% max

Sodium metabisulfite: Na₂S₂O₅

5-7 %

5-7%

5-7%

Sodium bisulfite:NaHSO₃

0.5 max

0.5% max

0.5% max

Sodium carbonate: Na₂CO₃

1.5% max

1.5% max

1.5% max

Sodium formate: HCOONa

0.5 % max

0.05% max

0.05% max

Zn

0.0001 % max

0.0001% max

0.0001% max

Fe

0.005 % max

0.005% max

0.002% max

Physical appearance

White crystalline powder