Sodium Formaldehyde Sulfoxylate  (Rongalite)
Molecular formula  : NaHSO₂^.CH₂O^.2H2O
Techinal data:
Appearance             White powder
Content                   98% min
Solution in water     Clear solution or slight turbid
Sulfide                     No presence of black color
Odour                      No odour or little smell of leek