ISO 8986-1:2009 establishes a system of designation for polybutene‑1 (PB‑1) thermoplastic materials which may be used as the basis for specifications.The types of polybutene plastics are differentiated from each other by a classification system based on appropriate levels of the designatory property melt volume-flow rate and on information about basic polymer parameters, intended application and/or method of processing, important properties, additives, colorants, fillers and reinforcing materials.ISO 8986-1 is applicable to all butene homopolymers and to copolymers of butene with a maximum content of other 1‑olefinic monomers of less than 50 % by mass and with a content of non-olefinic monomers with functional groups up to a maximum of 1 % by mass.It applies to materials ready for normal use in the form of powder, granules or pellets and to materials unmodified or modified by colorants, additives, fillers, etc.