ISO Microbial Content Testing (Cosmetics)

The ISO Microbial Content methods are International Standards which are specifically used for testing of cosmetic products to quantitate bacteria, yeast and mold that may be present in a product. Additionally, qualitative enrichment testing of the samples in a non-selective growth medium with subculture to selective/differential media can detect objectionable organisms that may be present in the cosmetic product. The following ISO Standards are performed at CPT Laboratories:

ISO 21149 Cosmetics — Microbiology 
Enumeration and detection of aerobic mesophilic bacteria

ISO 16212 Cosmetics — Microbiology
Enumeration of yeast and mold

ISO 21150 Cosmetics — Microbiology
Detection of Escherichia coli

ISO 22717 Cosmetics — Microbiology
Detection of Pseudomonas aeruginosa

ISO 22718 Cosmetics — Microbiology
Detection of Staphylococcus aureus

ISO 18416 Cosmetics — Microbiology
Detection of Candida albicans

Test Method Suitability per ISO Methods (Required)

Prior to performing MLT testing on any specific product or material-type, the ISO methods require that method suitability be conducted. This is to ensure that the product/material does not inhibit recovery of organisms which may be present and could result in ‘false negative’ test results. Any antimicrobial properties present in the product/material can be eliminated by dilution, filtration, neutralization or inactivation before testing that product or material. This determines the valid dilution to be used for testing that product or material on a routine basis.