Microbiological purity tests of cosmetics
Testing the microbiological purity of cosmetics is an important element in developing the most important document proving the quality of a given product, i.e. the cosmetic product safety report. On its basis, it is possible to draw conclusions about the safety of a given cosmetic product placed on the market by the manufacturer. The requirement to test the microbiological purity of cosmetic products or raw materials intended for their production results directly from Regulation (EC) No. 1223/2009 of the European Parliament and of the Council of November 30, 2009, applicable throughout the European Union.
Risk of cosmetic contamination
The greatest risk in terms of microbiological contamination are cosmetics containing a high water content or based on it. Water in cosmetic products may be a potential source of bacteria from the Pseudomonas group (including Pseudomonas aeruginosa) or Escherichia coli, which are pathogenic microorganisms, so their presence in cosmetic products is unacceptable. This is one of the reasons why it is important not only to control the microbiological quality of finished products, but also to periodically test raw materials, such as production water.
Types of testing the microbiological purity of cosmetics
The overall microbiological purity test is influenced by quantitative and qualitative analyses, which focus on the total number of microorganisms. Qualitative analyzes are performed to detect the presence of specific microorganisms, i.e. undesirable microorganisms in cosmetic products, aerobic mesophilic bacteria or yeasts that are pathogenic and harmful to human health, such as: Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa and Candida albicans.
Cosmetics testing methods
Various microbiological culture media are used to detect the presence of each of the desired microorganisms. The testing procedure is performed in accordance with applicable ISO standards. Thus, in order to detect the presence of Escherichia coli bacteria in a given product, inoculation should be performed on MacConkey’s selective and differentiating medium, where these bacilli will form dark pink colonies with a characteristic dark pink border around them. Baird-Parker selective and differentiating medium is used to isolate Staphylococcus aureus. Coagulase-positive staphylococci grown on this medium will have a black color with a characteristic clear zone around it. To detect Pseudomonas aeruginosa bacteria, a selective CET (Cetrymide Agar) medium is used, which will detect characteristic neon yellow-green bacterial colonies. To check the presence of yeast-like fungi of the genus Candida in a cosmetic product, surface inoculation should be performed on a selective medium for the isolation of Sabouraud fungi with dextrose and chloramphenicol, on which Candida albicans will grow in the form of large, snow-white colonies.
Please contact the Customer Service Office to learn more about the detailed offer of cosmetics tests provided by the Ekolabos laboratory: 22 378 30 34 or cosmetics@ekolabos.pl
