Commercial cosmetics such as mascara and skin creams often contain thimerosal. According to EWG's Skin Deep Cosmetic Database, Love My Eyes brand mascara contains dangerously high levels of thimerosal. No American made skin creams have been reported to contain thimerosal, but those that aim to lighten skin and are produced in countries like China and Mexico include the ingredient.
Thimerosal is a preservative that contains mercury and is most commonly used in flu vaccines and cosmetics. Its use may cause irritation, allergic reactions and neurotoxic symptoms. Those using products containing thimerosal during pregnancy run the risk of brain damage to the fetus; the same risk is present for infants and children on whom the products are used.
The FDA has severely limited the use of thimerosal and other mercury-based preservatives in cosmetics. For most products, one part per million is the allowable mercury dose. This is higher for eye products such as mascara, wherein the allowable dose is 65 parts per million. This is because thimerosal has proven to be an effective preventative of the development of bacteria in mascara, which is then easily spread to the eyes during application. The inclusion of thimerosal in mascara helps ward off Pseudomonas infections that could potentially leave their victims blind.