Cosmetic products: Beware of bacterial contamination!
No one would want to apply a cosmetic product contaminated with fecal bacteria, but this is the case for 70 to 90% of the products tested in a new scientific study. Mascara, eyeliner, and especially makeup sponges become bacteria traps once opened. Some of them can be potentially dangerous to health.
Makeup
Eyeliner, lipstick, foundation, mascara, and makeup sponges are included in many feminine hygiene products. Although these products are designed according to strict microbiological standards, they become true bacterial nests when used. A study published in the Journal of Applied Microbiology shows that 70% to 90% of those tested have a very high microbiological load. Even more worrisome, some of these bacteria can pose a health risk.
Scientists have studied about 100 samples in various product categories (eyeliner, lipstick, gloss, mask, and makeup sponges), all collected from English consumers who have already used them. Each was subjected to two tests: the evaluation of the total number of bacteria per milliliter of product and the precise identification of the bacterial species.
The most contaminated cosmetic accessory is the makeup sponge. These synthetic sponges used to spread the foundation can contain more than one million bacteria per gram of sponge! Gloss is the second most contaminated, with more than 1,000 bacteria per milliliter, followed by mascara, which has just under 1,000 bacteria per milliliter.
The European standard allows a maximum of 1,000 bacteria per gram or milliliter of product for a cosmetic on the face and only 100 for a cosmetic around the eyes. Only 4 to 6% of the products tested in the study were “clean”!
Potentially pathogenic germs in cosmetics
In total, 48 different species were identified in all products tested. Although it seems normal to find some that live on the skin, such as commensal staphylococci, it is more worrying to find enterobacteria, usually those affected by fecal contamination.
The famous Escherichia coli favors makeup sponges and eyeliner. Many other potentially pathogenic species have also been identified. Pseudomonas aeruginosa and Citrobacter freundii are opportunistic germs that can become virulent if conditions are favorable for them. Both are found in glosses, lipsticks, and sponges, and present a potential risk of infection if found near mucous membranes such as the mouth and eyes.
The study points to poor hygiene habits among consumers, especially in the case of make-up sponges. According to their questionnaire, 93% of makeup sponges were never washed, and 64% fell on the floor without additional cleaning. “Advice on the use and cleaning of these products is needed to avoid contamination by potentially pathogenic microorganisms,” says Amreen Bashir of the University of Birmingham, which conducted the study. A conscious removal of makeup makes sense!
References
Bashir, A., & Lambert, P. (2020). Microbiological study of used cosmetic products: Highlighting possible impact on consumer health. Journal of Applied Microbiology, 128(2), 598–605. https://doi.org/10.1111/jam.14479
