ISO 18664:2015规定了中药中铅（Pb）、砷（As）、镉（Cd）和汞（Hg）的测定方法。适用于在国际贸易中作为食品补充剂、功能性食品或天然药物销售和使用的中药天然原料，包括中药（全药材）和植物或动物的饮片。它不适用于中药中使用的矿物药物。 ISO 18664:2015无意为单个国家设定最大限值（ML）；相反，它旨在为标准化测试方法和风险评估提供参考。

ISO 18664:2015 specifies determination methods of lead (Pb), arsenic (As), cadmium (Cd) and mercury (Hg) in herbal medicines used in Traditional Chinese Medicine (TCM). It is applicable to natural materials of TCM that are sold and used as food supplements, functional foods or natural medicines in international trade, including Chinese materia medica (whole medicinal materials) and decoction pieces derived from plants or animals. It is not applicable to mineral drugs used in TCM. ISO 18664:2015 is not intended to set maximum limits (ML) for individual nations; rather, it is intended to give a reference for standardized testing method and risk assessment.