ISO 18415:2007 gives general guidelines for the detection and identification of specified microorganisms in cosmetic products as well as for the detection and identification of other kinds of aerobic mesophilic non-specified microorganisms in cosmetic products.

Microorganisms considered as specified in this International Standard might differ from country to country according to national practices or regulations. Most of them considered as specified microorganisms include one or more of the following species: Pseudomonas aeruginosa, Escherichia coli, Staphylococcus aureus and Candida albicans.

The method described in ISO 18415:2007 is based on the detection of microbial growth in a non-selective liquid medium (enrichment broth) suitable to detect microbial contamination, followed by isolation of microorganisms on non-selective agar media. Other methods can be appropriate depending on the level of detection required.

In ISO 18415:2007 specific indications are given for identification of Pseudomonas aeruginosa, Escherichia coli, Staphylococcus aureus and Candida albicans. Other microorganisms that grow under the conditions described in this International Standard, may be identified by using suitable tests according to a general scheme.