VIRGINIA BEACH, Va. — March is the time of the year when people focus on spring cleaning.
People clean their cars, homes, and closets, but how many refresh their makeup bags?
I’ll be honest, I don’t clean mine as often as I should. But I thought, how bad could it be?
To put it to the test, I brought my bag, brushes, and products to the biology lab at Virginia Wesleyan University.
I met with Dr. Caitlin Williams, an assistant professor of Biology. We started by unloading my used makeup (mascara, foundation, brushes) as well as new, unused makeup.
Dr. Williams and her two students, Veronika, and Jack, set up the experiment.
The first step was to dip a sterile swab into a sterile tube of water and then wipe the product that was being tested.
Dr. Williams, Veronika, and Jack said it was best to swab the product where it’s used the most. For example, on my foundation brush, they swabbed the brush across the top where it touches my face and the product.
Whatever bacteria was picked up on the swab was then rubbed across the testing plate.
We repeated the process more than 20 times, each plate testing for a different bacterium.
"Oh, this isn't even moving, Erin.... It doesn't even move!" Dr. Williams says with a laugh as she swabs my concealer brush.
As we swabbed each product, Dr. Williams explained what can happen at a micro-level when you don't clean your stuff regularly.
"Dead skin cells can be food for the bacteria to grow on your brushes," she says.
After one round of swabbing, I cleaned the brushes in the bathroom before we evaluated them again without product.
Once we completed that process, we collected the plates and put them in an incubator where they would sit for several days.
Over four days, we let the plates culture to see if the bacteria multiplied.
Spoiler alert, they did.
We learned the concealer brush, foundation sponge, and makeup bag collected the most bacteria.
"The big textured-looking colonies are fungus," Dr. Williams says.
She also did an additional test and found something concerning.
"This plate changed colors. This was red before. Now it's yellow and that's indicative of it being staphylococcus aureus, which is pathogenic," she says. "This came from the concealer brush."
I was shocked. I told her that my concealer brush is one of the closest things I put to my eye, and I use it every day.
After I freaked out, for several minutes, I sat down with Dr. Williams to talk about what we found.
I asked her if it was surprising that we found staph on my brush.
"Not at all," she says. "I expected to see a good amount of staph species growing on the plates from makeup because again, those are touching your skin."
She says it also could have been the way I store my makeup; packed together in a small bag.
"I think the brushes and sponges probably stay more damp which is going to create an environment for more microbes to grow," she says.
But it’s important to add context to this experiment because there are microbes on everything. She says the vast majority of them are not dangerous.
She says, "You and everything around you is covered in microbes, right? I tend to emphasize bacteria because that's my focus, but also fungus, also viruses are on everything. They're there for a reason and they're actually preventing you from being infected by other organisms that can hurt you."
So, clean your brushes and bags and keep an eye on the expiration dates on your products.
"It's really nice to be like, let's answer a real question that's relevant and learn something that is really useful," Dr. Williams says.
