Aims To investigate the nature and extent of microbial contamination in five categories of used cosmetic products (lipstick, lip gloss, eyeliners, mascaras and beauty blenders) and highlight the potential risk posed to consumers in the UK. Methods and Results Used products were donated and microbial contents were determined by microbial culture and identification. About 79-90% of all used products were contaminated with bacteria, with bacterial loads ranging between 10(2) and 10(3) CFU per ml, beauty blenders contained an average load of >10(6) CFU per ml. Presence of Staphylococcus aureus, Escherichia coli and Citrobacter freundii was detected. Enterobacteriaceae and fungi were detected in all product types, and were prevalent in beauty blenders (26 center dot 58 and 56 center dot 96% respectively). Ninety-three per cent of beauty blenders had not been cleaned and 64% had been dropped on the floor and continued to be used. Conclusions Significant levels of microbial contamination occur during use of cosmetic products and presence of pathogenic organisms pose a potential risk to health. Significance and Impact of the Study The nature and high level of contamination in used cosmetic products indicate that greater user awareness and education are required. Manufacturers should ensure that product expiry dates are prominently displayed and consumers can identify the symbols used on product packaging.