The purpose of the test is to establish the level to which the abrasive is contaminated by foreign matter. The level of foreign matter, e.g. oxides and residual metallurgical slag, is determined by magnetic separation. This is one of a number of parts of ISO 11125 dealing with the sampling and testing of metallic abrasives for blast-cleaning. The types of metallic abrasive and requirements on each are contained in the various parts of ISO 11124. The ISO 11124 and ISO 11125 series have been drafted as a coherent set of International Standards on metallic blast-cleaning abrasives. Information on all parts of both series is given in Annex A. This part of ISO 11125 specifies a test method for the determination of foreign matter in metallic blast-cleaning abrasives.