You won’t want to turn a blind eye to cleaning those dirty makeup brushes ever again.

A new study has revealed the horrifying amount of bacteria that accumulates on unwashed brushes, no matter where they’re stored – and it’s the same or more than a toilet seat.

Conducted by cosmetic tools brand Spectrum Collections, researchers swabbed clean and “unclean” makeup brushes at the end of the two-week trial period, while also testing various common storage methods: at a bedroom vanity, in a makeup bag, in a brush-specific bag, a drawer and a bathroom holder.

Comparing the results to the swab of a toilet seat, the study found that, no matter where the brushes were stored, the number of bacteria was either the same or more than the toilet.

Cosmetic scientist Carly Musleh told Spectrum Collections that makeup brushes can transfer bacteria, dead skin cells and oil from face to product. While not all kinds of bacteria are necessarily harmful, routinely using dirty brushes can result in acne or worse.

“Using dirty brushes could increase the risk of causing an imbalance in the healthy microbial community and lead to an increase in the number of pathogenic microbes which could cause breakouts or more serious issues like impetigo or Staphylococcal (Staph) infections,” she said.

“To reduce the build-up of bacteria it is important to clean makeup brushes regularly.”

The cosmetic tools company surveyed their own customers, 40% of whom said they clean their brushes biweekly, while a staggering 20% admitted to only washing them every one to three months.

The American Academy of Dermatology Association recommends cleansing brushes every seven to 10 days.

“We’re all guilty of leaving it a bit too long,” Spectrum Collections co-founders Hannah and Sophie Pycroft said while highlighting the importance of cleaning brushes “at least once a week.”

“It was not surprising that through our research it revealed that many of us don’t keep on top of this cleaning – with it being apparent that many of us don’t understand the impact not cleaning our brushes can have on our skin.”

In addition to storing brushes in closed containers to avoid any airborne debris, bacteria or dust that could collect, makeup wearers should wash the bristles in a brush-specific cleanser or gentle shampoo in lukewarm water, pat dry with a clean towel and lay them out to dry either hung upside down or on their side.

Past experiments have gotten down and dirty with cosmetics and yielded similar results, as one beauty guru advised regular sanitation of brushes – even after one use.

One even woman revealed she was left partially blind due to a dirty makeup bag, which clinicians believed contaminated her contact lenses.