CHALLENGE TEST

A challenge test, also known as a preservative efficacy test, is an essential component of the safety evaluation process for cosmetics. The requirement for conducting a challenge test is outlined in the SCCS NoG 12th Edition, which specifies the demand for this test. In addition, the use of specific germs, which are known to lead to spoilage of cosmetic products, is recommended by the SCC. Those germs are Pseudomonas aeruginosa, Staphylococcus aureus, Aspergillus brasiliensis and Candida albicans.

Various methods are employed within the cosmetic industry, differing in the choice of microorganisms, sample inoculation techniques, acceptance criteria, and considerations for preservative stability. Most methods assess log reduction after 28 days, although some extend the testing period to 42 days. In the EU, the Eur. Ph. and ISO 11930 are the most widely used methods, while other alternatives include CFTA M-3, CTFA M-4, ASEAN, KoKo test, and USP 35 chapter 51.

It’s important to note that products classified as low-risk according to ISO 29621 standards are exempt from undergoing a challenge test.

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