- Never allow other people to borrow your makeup, which can spread bacteria and other germs. - When trying on makeup at a store, always use a new applicator, or ask the salesperson to clean it with alcohol before using. - To prevent bacterial growth, keep your makeup closed tightly, and store it in a cool, dry place. Avoid exposing makeup to sun and other forms of direct light and heat. - If you have an eye infection, stop using makeup until the irritation clears. Discard any makeup you used when you had the infection. - Throw away old makeup, and any makeup that turns color or develops an odor. - Try not to inhale powders or aerosol products, which can irritate or damage the lungs.