This part of the standard establishes a system of designation for styrene/acrylonitrile thermoplastic material, which may be used as the basis for specifications. The types of styrene/acrylonitrile plastic are differentiated from each other by a classification system based on appropriate levels of the designatory properties a) Vicat softening temperature b) melt flow rate and on information about basic polymer parameters, intended application and/or method of processing, important properties, additives, colourants, fillers and reinforcing materials.