This part of ISO19066 establishes a system of designation for methyl methacrylate-acrylonitrile-butadiene-styrene (MABS) moulding and extrusion materials, which can be used as the basis for specifications. The types of MABS plastic are differentiated from each other by a classification system based on appropriate levels of the designatory properties Vicat softening temperature, melt volume-flow rate, Charpy notched impact strength, and tensile modulus, and on information about composition, intended application and/or method of processing, important properties, additives, colorants, fillers, and reinforcing materials. This part of ISO19066 is applicable to all methyl methacrylate-acrylonitrile-butadiene-styrene materials consisting of a continuous phase based mainly on copolymers of styrene (and/or an alkyl-substituted styrene), acrylonitrile and methyl methacrylate, and a dispersed elastomeric phase based on butadiene. It applies to MABS materials ready for normal use in the form of powder, granules, or pellets, unmodified or modified by colorants, additives, fillers, etc. It is not intended to imply that materials having the same designation give necessarily the same performance. This part of ISO19066 does not provide engineering data, performance data, or data on processing conditions which might be required to specify a material for a particular application and/or method of processing. If such additional properties are required, they will be determined in accordance with the test methods specified in ISO10366-2, if suitable. In order to specify a thermoplastic material for a particular application or to ensure reproducible processing, additional requirements can be given in data block 5 (see 3.1).