Waterproof cosmetics are designed not to come off, run or smear, even when wet. This can be helpful in extremely humid areas where make-up tends to run. Waterproof cosmetics are also useful for female athletes whose perspiration might affect their make-up; or for anyone that wants their make-up to look as though it was just applied, despite rain or tears. Finally, waterproof cosmetics are great for the beach or poolside vacations, when women want to look their best without sacrificing time in the water.

Most cosmetics have an ingredient called dimethicone, which is a silicone-based oil. Dimethicone helps keep skin soft and assists in giving a smooth application of the product. Waterproof cosmetics contain a special form of dimethicone called dimethicone copolyol. This is a waterproof version of the same oil, formulated to adhere to skin and hair.

While waterproof cosmetics can be very convenient for women who want to keep their make-up looking fresh and clean regardless of their circumstances, it is not always healthy. Most waterproof cosmetics require special solvents for removal. These solvents are usually quite harsh and will also remove sebum. Sebum is an oily substances produced in the skin which serves as a barrier to chemicals, irritants, and pollutants. When sebum is removed, the skin is vulnerable to infection, sun burn and other problems. Additionally, the continual removal of sebum will cause skin to be unusually dry, leading to premature aging and wrinkles.

Waterproof cosmetics should not be used by women suffering from eyelid dermatitis. Eyelid dermatitis is an allergic reaction to compounds that come into contact with the skin. Often it appears as a rash or puffiness on the eyelids and surrounding area. Waterproof cosmetics will only serve to further irritate eyelid dermatitis due to the adhesive chemicals and removal techniques.

While waterproof cosmetics are useful for events such as weddings, anniversaries, prom night, or other special occasions, excessive use can lead to potential damage to the skin. The best option is to save waterproof make-up for those rare occasions.