Microbiological purity assessment of cosmetics used by one and several persons and cosmetics after their expiry date

Microbiological purity of cosmetics provides safety of users during their use, prevents physicochemical changes of a preparation, infections and diseases of the skin.The aim of this study was to assess the level of microbiological contamination of cosmetics used by one person and by several people and cosmetics after their expiry date in relations to standards for marketed cosmetics, ensuring safety of their use.This study was conducted using 55 samples representing 19 types of cosmetics, divided into three groups: used by one person, used by several people and after the expiry date. In cosmetic samples the general numbers of aerobic mesophilic bacteria were determined with the spread plate method on tryptic-soy agar. The presence of Staphylococcus aureus, Pseudomonas aeruginosa and Candida albicans were also checked.The number of aerobic mesophylic bacteria in the tested cosmetics ranged from the level below the method detectability to 1.3×107 cfu/g or ml. The presence of Staphylococcus spp. was found in 11 (20.0%) tested cosmetic samples and of P. aeruginosa in one tested preparation. Yeasts C. albicans were not detected, whereas contamination with fungi Aspergillus spp. and Penicillium spp. ranging from 0.5×101 to 1.5×101 cfu/g or ml was recorded in four cosmetics. The level of microbiological contamination of cosmetics used by several people was higher than that of cosmetics used by one person. Cosmetics after the expiry date showed the highest microbiological contamination.The number of users of cosmetic and it expiry date exceeding influenced the level of microbial contamination of preparations.