According to inventors at Repairogen Corp., Cornell University and the University of Louisville Research Foundation, various cosmetic compositions can impair, damage and/or irritate the skin and hair. For example, some byproducts of unstable sunscreens can give rise to contact dermatitis, acne, rashes and inflammation, even in hair follicles. Keratolytic agents such as alpha hydroxy acids and retinoids also are recognized to irritate skin.
