ISO 1833-7:2017规定了一种使用甲酸测定聚酰胺纤维质量百分比的方法，该方法在去除非纤维物质后，用于测定由以下混合物制成的纺织品中聚酰胺纤维的质量百分比: -聚酰胺 具有 -棉、粘胶、铜、莫代尔、lyocell、聚酯、聚丙烯、氯纤维、丙烯酸、玻璃纤维、弹性多酯、弹性烯烃和三聚氰胺，或 -羊毛（如果羊毛含量小于或等于25%），或动物毛纤维。 当羊毛含量超过25%时，ISO 1833-7:2017不适用；ISO 1833-4适用。

ISO 1833-7:2017 specifies a method, using formic acid, to determine the mass percentage of polyamide fibre, after removal of non-fibrous matter, in textiles made of mixtures of - polyamide with - cotton, viscose, cupro, modal, lyocell, polyester, polypropylene, chlorofibre, acrylic, glass fibre, elastomultiester, elastolefin and melamine, or - wool (if the wool content is less than or equal to 25 %), or animal hair fibres. ISO 1833-7:2017 does not apply when the wool content exceeds 25 %; ISO 1833-4 applies.