一种物质的形式何时会变成一种新物质，例如基于表面改性？

一种物质的形式何时会变成一种新物质，例如基于表面改性？

When would a form of a substance become a new substance, e.g. based on surface modifications?

REACH法规将物质定义为“一种化学元素及其化合物”。当一种物质的化学元素或其化合物发生改变时，该物质即成为另一种物质。因此，根据REACH法规，物质形态的改变，包括将其改性为纳米形态，并不会使该物质成为另一种物质。REACH法规还规定，纳米形态的表面处理不会产生新的物质，而会形成该物质的一种新的纳米形态。每种纳米形态都必须在注册档案中进行具体表征和报告。

The REACH Regulation defines a substance as “a chemical element and its compounds”. A substance becomes a different substance when there is a modification of the chemical element or the compounds that compose it. Following from this, the modification of the form of a substance, including its modification into a nanoform, does not make it a different substance under REACH.  REACH also specifies that the surface treatment of a nanoform does not lead to the creation of a new substance, but a new nanoform of the substance concerned. Each nanoform must be specifically characterised and reported in the registration dossier.