This document establishes a system of designation for sulfone polymer moulding and extrusion materials, including polysulfone (PSU), polyethersulfone (PESU) and polyphenylsulfone (PPSU), which can be used as the basis for specifications.The types of sulfone polymer materials are differentiated from each other by a classification system based on appropriate levels of the designatory properties temperature of deflection under load, melt mass-flow rate, Charpy notched impact strength, tensile modulus, and yield stress, and on information about composition, intended application and/or method of processing, important properties, additives, colorants, fillers and reinforcing materials.This document is applicable to all sulfone polymers that contain ether oxygen, which is a necessary component of the polymers as in the diphenyl sulfone moiety. It applies to sulfone polymer materials ready for normal use in the form of powder, granules or pellets, unmodified or modified by colorants, additives, fillers, etc.This document not intended to imply that materials having the same designation necessarily give the same performance. It does not provide engineering data, performance data or data on processing conditions which can be required to specify a material for a particular application and/or method of processing.If such additional properties are required, they are determined in accordance with the test methods specified in ISO24025-1, if suitable.In order to specify a thermoplastic material for a particular application or to ensure reproducible processing, the requirements are given in data block 5 (see 4.1).