3. Storing cosmetics in heat.
Don’t store makeup in warm or hot places, such as your purse or a suitcase in the trunk of the car on a warm day.
All makeup, including mascara and eye shadow, can breed bacteria, especially in hot temperatures, Dr. Wang warns.
“Heat destroys preservatives, [which] keep bacteria at bay, so they can grow easily,” she says.
So toss makeup exposed to heat.
4. Mixing up makeup.
Don’t use a lip pencil on your eyes. Only use makeup for their intended use. The danger? You guessed it: bacteria.
Bacteria in saliva in the mouth and lips differ from bacteria in and around the eyes. Although lip bacteria won’t cause infection in the mouth, they may in the eyes, Dr. Wang says.
“I had a patient once who was flossing, and a little bit of what was in her teeth went into the eye and caused an infection,” she says.
And, never spit into eye cosmetics, the FDA warns.