This European Standard specifies the compositions of copper-based master alloys intended for the manufacture, deoxidation, or desulfurization of cast or wroughtalloys, especially those based on copper supplied in the form of ingots, notchedbar, notched slab, granules or broken pieces. A procedure is included for sampling the master alloys for analysis for verification of conformity to the composition requirements. A method for the determination of chromium (III)-oxide in chromium-copper master alloy is given in annex A.