It's ironic that cosmetic consumers—who are a primary reason products need preservatives—are the force behind a movement to omit them from products. This is not news to product developers but the fact that mainstream media is picking up on a study about used products and their resulting contamination is.
In its report, "Are Dangerous Microbes Hiding in Your Makeup? New Study Says Yes," Forbes reviewed research from Aston University published in the Journal of Applied Microbiology. In it, used products were collected through donations and their microbial contents were evaluated.
In total, 467 products from five makeup categories were donated by users from in the UK in response to social media ads, including: lipstick (96), eyeliner (92), mascara (93), lip gloss (107) and beauty blenders/applicators (79). Information regarding the duration of use of each product also was collected where possible.
Researchers found that approximately 79-90% of all used products were contaminated with bacteria, with loads ranging between 102 and 103 CFU per mL. Furthermore, the presence of Staphylococcus aureus, Escherichia coli and Citrobacter freundii was detected. Enterobacteriaceae and fungi also appeared in all product types but especially beauty blenders; 93% of beauty blenders had not been cleaned and 64% had been dropped on the floor and continued to be used.
In the Forbes report, Amreen Bashir, Ph.D., lead author on the study, noted these results underline consumers' poor hygiene practices when it comes to using makeup. In addition, requirements for expiration dates vary widely around the world. Taken together, this suggests consumers need to be educated about the use of products, including how to thoroughly wash beauty blenders.
The study authors also suggest that manufacturers prominently display expiration dates on product packaging. The real test, however, is whether consumers follow the directions. In the meantime, this reiterates the desperate need to ensure products are properly preserved to protect the formula from its user.