REACH 如何定义聚合物？

REACH 如何定义聚合物？

How is a polymer defined under REACH?

聚合物是由分子组成的物质，其特征是一种或多种单体单元的序列。此类分子的分子量必须分布在一定的范围内。分子量的差异主要归因于单体单元数量的差异。根据 REACH 法规第 3(5) 条，聚合物定义为满足以下标准的物质：i) 聚合物分子（即，至少包含三个单体单元，且这些单体单元与至少一个其他单体单元或其他反应物共价结合的分子）占总重量的 50% 以上；以及 ii) 具有相同分子量的聚合物分子数量必须少于总重量的 50%。更多信息，请参阅《单体和聚合物指南》第 2.2 节以及《注册指南》第 2.2.3.7 节。

A polymer is a substance consisting of molecules characterised by the sequence of one or more types of monomer units. Such molecules must be distributed over a range of molecular weights. Differences in the molecular weight are primarily attributable to differences in the number of monomer units.A polymer is defined, under Article 3(5) of REACH, as a substance meeting the following criteria:i)  Over 50 percent of the weight consists of polymer molecules (i.e. molecules containing at least three monomer units which are covalently bound to at least one other monomer unit or other reactant); and,ii) The amount of polymer molecules presenting the same molecular weight must be less than 50 percent of the weight.For further information, see section 2.2 of the Guidance for monomers and polymers and Section 2.2.3.7 of the Guidance on registration.