Oxybenzone This penetration enhancer (i.e., chemical that helps other chemicals penetrate the skin) undergoes a chemical reaction when exposed to UV rays. When oxybenzone is absorbed by your skin, it can cause an eczema-like allergic reaction that can spread beyond the exposed area and last long after you're out of the sun. Experts also suspect that oxybenzone disrupts hormones (i.e., mimics, blocks, and alters hormone levels) which can throw off your endocrine system. Accord