ISO 21149:2017给出了化妆品中需氧中温细菌计数和检测的一般指南 -在有氧培养后在琼脂培养基上计数菌落，或 -通过检查浓缩后是否有细菌生长。 由于该应用领域的化妆品种类繁多，该方法可能不适用于某些产品的每个细节（例如某些水不溶性产品）。如果已证明其等效性，或已证明该方法适用，则可使用其他方法（如自动方法）代替此处提供的试验。 如果需要，可以使用参考文献中给出的标准中描述的适当鉴定试验来鉴定列举或检测到的微生物。 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）包括水活性低的产品、水醇产品、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.