Cosmetics testing - Microbiology of cosmetics. Detection of Escherichia coli (EN ISO 21150: 2016).
Test accredited by ENAC (National Accreditation Entity).
The test provides information about the presence, or absence, of Escherichia coli in 1 g or 1 mL of the cosmetic sample. To perform the test, the cosmetic is diluted in the ratio 1:10 in an enrichment broth directly, when it is are miscible in water. When the cosmetic is not miscible in water is premixed with a solubilizing agent (polysorbate 80) and subsequently added to the enrichment broth. The enrichment broth should contain a neutralizer when the cosmetic tested contains any antimicrobial agent as preservatives. Neutralizers used must have been previously validated by a validation test. The presence or absence of Escherichia coli in the cosmetic is determined after incubation for 24 to 72 hours at 32.5ºC in the enrichment broth, and reseeding on a selective and differential medium. If colonies compatible with Escherichia coli are observed they are identified by conventional biochemical identification tests and reseeding on selective agar for confirmation.