The legal definition of a nanomaterial differs around the world, meaning that the same material may be classified as a nanomaterial, or not, depending on the country where it is classified. The first steps towards converging on an international definition are to recognize the differences between existing nanomaterial definitions and to agree on particle counting methods. Meanwhile, we propose a naming convention that indicates the key criteria of a specific definition of a nanomaterial.

中文翻译：

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全球监管纳米材料定义中纳米颗粒的计数方式

纳米材料的法律定义在世界各地有所不同，这意味着相同的材料可能被归类为纳米材料，也可能不被归类为纳米材料，具体取决于其分类国家。达成国际定义趋同的第一步是认识到现有纳米材料定义之间的差异，并就粒子计数方法达成一致。同时，我们提出了一个命名约定，表明纳米材料特定定义的关键标准。