This International Standard specifies a method for the determination of the solubility of pulp in cold sodium hydroxide solutions of various and fixed concentrations. The sodium hydroxide concentrations most frequently used are 18 and 10 % (m/m).
The method is mainly intended for the investigation of bleached pulps, but may, however, also be used with unbleached pulps, for example in the different stages of
manufacture of bleached pulp.