This International Standard specifies a method for determining insoluble matter in sodium chloride for industrial use. It also describes the preparation of principal solutions for other determinations. NOTE - Sodium chloride for industrial use may contain components that are only very slightly soluble or dissolve very slowly in water. Insoluble substances in sodium chloride for industrial use shall therefore be defined by the conditions of determination described in this International Standard. These conditions reproduce those normally used during the handling of salt for industrial use. The object is not to dissolve all the impurities but only those of interest to users.