Consumer Awareness of Microbial Contamination and Identification of Key Pathogenic Bacteria in Lip Cosmetic Testers

Background: With the increasing popularity and diversification of cosmetic products, an expanding number of retail stores are providing in-store testers to allow consumers to try products before purchasing. However, growing concerns have been raised about microbial contamination and the associated risk of infection due to the shared use of these testers. This study aimed to investigate consumer awareness and perceived susceptibility to microbial infection associated with the use of lip cosmetic testers, and to identify major pathogenic bacteria, thereby offering evidence to support the need for improved hygiene management practices. Methods: The survey examined the use of lip cosmetic testers and related side effects, as well as perceptions of product hygiene and microbial contamination. Awareness of microbial infection and consumer sensitivity to product safety were measured using a five-point Likert scale. Microorganisms were detected through PCR analysis of genomic DNA. Results: Among 134 respondents, 95% had previously used lip cosmetic testers, and 90% recognized the potential for microbial contamination. Sensitivity to product safety was not significantly associated with sociodemographic factors. However, susceptibility to microbial infection from tester use was significantly higher among participants of older age and with higher education levels. PCR analysis of lip cosmetic testers revealed frequent detection of Staphylococcus epidermidis and Pseudomonas aeruginosa. Other detected bacteria included Streptococcus oralis, Streptococcus salivarius, Streptococcus pneumoniae, and Escherichia coli, all of which are known to cause oral and respiratory infections. Conclusions: The analysis revealed that the majority of individuals who have used lip cosmetic testers expressed a high level of concern regarding product contamination and the potential for infection. Multiple pathogenic bacteria linked to oral and respiratory diseases were identified in the opened tester products. These findings underscore the necessity of establishing regulatory guidelines for the management of lip cosmetic testers and highlight the importance of enhancing consumer awareness regarding hygiene practices.