This document specifies the minimum requirements for quality control of microbiology culture media and diluents in order to demonstrate their ability to detect microorganisms and to ensure reliability of the microbiological test methods described in the ISO Cosmetics Microbiology Standards. Checking different parameters of media such as growth promotion, absence of microbial growth for non-inoculated media, physical characteristics, and batch contamination can help to assess their quality. This standard describes mainly growth promotion and microbial control tests and will apply to both commercially ready-to-use media and culture media prepared from dehydrated media or basic constituents in the user s laboratory. Other methods may be substituted provided that their equivalence has been demonstrated.