What are oxibenzones?

Answer 1

Oxybenzone is an organic compound and a derivative of benzophenone.

It is used as an ingredient in sunscreen and other cosmetics because it absorbs UVB and short-wave UVA (ultraviolet) rays.

A 2008 study by the US Centers for Disease Control and Prevention found the compound to be present in 96.8% of human urine samples analyzed as part of the National Health and Nutrition Examination Survey.

This organic compound has been shown to penetrate into the skin where it acts as a photosensitizer. This results in an increased production of free radicals under illumination, which makes this substance a possible photocarcinogen A study concludes that "determining what, if any, type of damage is done by ROS generated by UV filters needs to be explored." The fact that researchers have not discovered how free radicals possibly caused by this sunscreen agent compare with the damage known to be caused by UV ray exposure makes prohibition of it questionable at this point. Oxybenzone is a derivative of benzophenone, which can attack DNA when illuminated. It generates strand breaks and various photoproducts. Already in 1993 the use of oxybenzone had been strongly criticized, based on its similarity to benzophenone.

The photomutagenic properties of these compounds might be a contributing factor to the increased melanoma incidence that has been found in sunscreen users. Other possibilities include consequent overexposure to sun without UVA protection and vitamin D deficiency from overuse of sunscreen.

source: http://en.wikipedia.org/wiki/Oxybenzone