Sodium Metabisulfite

Sodium Metabisulfite is a strong reducing agent in aqueous solution. It binds the oxygen dissolved in water, it is used to remove FRC free residual chlorine in RO feed water to protect the membranes from oxidation.

Appearance: White or slightly Yellowish, fine crystalline powder, with an odour of SO2

Chemical Name: Sodium Metabisulfite, Na2S2O5

CAS No.: 7681-57-4

Bulk Density: 1 -1.2 kg/l

Water soluble

Parameter Unit Specification
Na2S2O5 g/100 g min 97.2
SO2 g/100 g min 65.5
pH value (5 % solution) - 4.0 – 4.8
NaCl mg/kg max. 50
Heavy metals as Pb mg/kg max. 10
Fe mg/kg max. 10
Properties:

Sodium Metabisulfite ( SMBS) is available in the form of a fine microcrystalline powder , it has a slight odour of sulphur dioxide.

With exposure to air , Sodium bisulfite solutions undergo oxidation

Sodium metabisulfite is a strong reducing agent in aqueous solution. It binds the oxygen dissolved in water and must therefore not be discharged untreated into rivers and lakes, because it may seriously disrupt animal and plant life.