The challenge test was performed for the products that were not contaminated using P. aeruginosa ATCC 9027. Results are summa- rized in Table 3. This table clearly demonstrates that nine out of 32 formulations of the cosmetic brands that were of acceptable microbiological quality at the point of sale were found to be inad- equately preserved. The neutralization procedure of preservatives in the products studied using Polysorbate 80 was effective as it was possible to recover more than 50% of the number of the challenge bacteria used in the test.