ISO 21149:2017给出了化妆品中存在的需氧嗜温菌的计数和检测的一般准则 - 通过在有氧培养后计数琼脂培养基上的菌落，或 - 通过检查浓缩后不存在细菌生长。 由于在这一应用范围内各种各样的化妆品，这种方法可能不适用于每个细节的某些产品（例如某些水不混溶产品）。其他方法（例如自动化）可替代本文提供的测试，只要其等同性已被证明或该方法已被证明是合适的。 如果需要，列举或检测的微生物可以使用参考书目中给出的标准中描述的合适的鉴定试验来鉴定。 为了确保消费者的产品质量和安全，建议进行适当的微生物风险分析，以确定本文件适用的化妆品类型。被认为具有低微生物风险的产品（见ISO 29621）包括水分低，含水酒精产品，极端pH值等。

ISO 21149:2017 gives general guidelines for enumeration and detection of aerobic mesophilic bacteria present in cosmetics - by counting the colonies on agar medium after aerobic incubation, or - by checking the absence of bacterial growth after enrichment. Because of the large variety of cosmetic products within this field of application, this method may not be appropriate for some products in every detail (e.g. certain water immiscible products). Other methods (e.g. automated) may be substituted for the tests presented here provided that their equivalence has been demonstrated or the method has been otherwise shown to be suitable. If needed, microorganisms enumerated or detected may be identified using suitable identification tests described in the standards given in the Bibliography. In order to ensure product quality and safety for consumers, it is advisable to perform an appropriate microbiological risk analysis to determine the types of cosmetic products to which this document is applicable. Products considered to present a low microbiological risk (see ISO 29621) include those with low water activity, hydro-alcoholic products, extreme pH values, etc.