ISO 22254:2005规定了测定手动牙刷刷毛部分抗偏转能力的试验方法。本国际标准适用于具有传统平饰设计的牙刷，可能不适用于具有其他设计的牙刷。使用本国际标准获得的结果可能与消费者对牙刷毛硬度的看法不符。

ISO 22254:2005 specifies a test method for determining the resistance of the tufted portion of manual toothbrushes to deflection. This International Standard is applicable to toothbrushes having a conventional flat trim design and may not be applicable to toothbrushes with other designs. The results obtained with this International Standard may not correspond to consumer perceptions of the stiffness of toothbrush bristles.