ABSTRACT
In an attempt to assess cosmetics containing 'nontraditional' preservatives, 93 eye area cosmetic products were selected based on labelled or marketed claims that these products were 'green', 'natural', 'paraben-free', 'preservative-free' or contained nontraditional preservatives (e.g. botanical extracts). Products were analysed for water activity, pH and microbiological content, which included enumeration of aerobic micro-organisms, detection of microbial growth after a 7-day enrichment and identification of microbial isolates. The survey found that 60% (56/93) of the eye area cosmetics were free of microbiological growth under test conditions, 32% (30/93) showed the presence of micro-organisms at low levels (<100 CFU per ml or g) and 8% (7/93) showed microbiological growth at higher levels (> 100 CFU per ml or g). Gram-positive bacteria such as Bacillus and Staphylococcus were the dominant genera identified in these cosmetic products, whereas Gram-negative species were relatively uncommon. The survey found a positive association between lower water activity cosmetics and the presence of micro-organisms in these products. Similarly, colour cosmetics were more likely to contain micro-organisms than noncolour cosmetics. The most represented micro-organisms in the survey were from genus Bacillus, suggesting that the natural raw materials are the likely source of observed microbial loads. SIGNIFICANCE AND IMPACT OF THE STUDY: In the United States, cosmetic products are regulated postmarket; therefore, surveillance programmes are one of FDA's most important tools for monitoring microbiological safety of cosmetics. 'Traditional' preservatives, such as parabens and formaldehyde releasers, are perceived unfavourably by some consumers, resulting in cosmetic manufacturers increasingly using 'nontraditional' preservatives. FDA conducted an analytical survey of eye area cosmetics that claimed to be free of traditional preservatives and determined microbiological loads in tested products. This study explores the association of microbial loads with the physical and chemical characteristics of the cosmetic products, and points to the limits of preservative activity in cosmetics.
