This International Standard specifies a titrimetric method for the determination of the carbonates content of sodium hydroxide for industrial use.
The method is applicable to products having carbonates contents, expressed as CO2, greater than 0,01 % (m/m) :
Three cases, selected by a preliminary test, are envisaged :
1 Sodium hydroxide containing neither sulphides nor
chlorates.
2 Sodium hydroxide containing sulphides.
3 Sodium hydroxide containing chlorates.