ISO 9988-1:2004 establishes a system of designation for polyoxymethylene (POM) thermoplastic materials, which may be used as the basis for specifications.The types of polyoxymethylene plastic are differentiated from each other by a classification system based on appropriate levels of the following designatory properties:melt mass-flow rate or melt volume-flow rate,tensile modulus,and on information about basic polymer parameters, intended application, method of processing, important properties, additives, colorants, fillers and reinforcing materials.This part of ISO 9988 is applicable to all polyoxymethylene homopolymers and to copolymers of polyoxymethylene and blends of polymers containing polyoxymethylene.It applies to materials ready for normal use in the form of powder, granules or pellets and to materials unmodified and modified by colorants, additives, fillers, etc.