An additional warning for all of us who keep our mascara in our purses; heat will quickly degrade the preservatives, allowing bacteria to proliferate faster. A few tips for mascara safety. Store mascara in a cool place.Toss mascara after a few months and replace.When applying mascara, stop at two coats. (Multiple layers can plug the oil glands along the edge of eyelids, causing styes. Don't ever apply mascara in the car; according to ophthalmologists, you'd be surprised how many women arrive in their offices with scratched (and possibly infected) corneas from poking themselves in the eye.These three hazards are certainly the top three beauty concerns today. However, there are a few other concerns to be aware of.