Cosmetics testing - Microbiology of cosmetics. Detection of Pseudomonas aeruginosa (EN ISO 22717: 2016).
Test accredited by ENAC (Spanish National Accreditation Entity).
The test provides information about the "presence or absence" of Pseudomonas aeruginosa 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 products are miscible in water. When cosmetic is non-miscible in water it is premixed with a solubilizing agent (polysorbate 80) and subsequently added to the enrichment broth. The enrichment broth should contain a neutralizer when testing cosmetic containing any antimicrobial agent as preservatives. Neutralizers used must have been previously validated by a validation test. The presence or absence of Pseudomonas aeruginosa in the cosmetic is determined after incubation for 24 to 72 hours at 32.5ºC in the enrichment broth, reseeding in a selective and differential medium. This medium should be incubated at 32.5ºC and observed at 24, 48 and 72 hours. If colonies compatibles with this bacteria are observed, they are identified by conventional biochemical microbiology tests and reseeding on selective agar for confirmation.