Titanium Dioxide has high UV light absorbing capabilities, and it is often used as an active ingredient in sunscreens; it is found to be resistant to discoloration under UV light. According to Wikipedia, "Sunscreens designed for infants or people with sensitive skin are often based on titanium dioxide and/or zinc oxide, as these mineral UV blockers are believed to cause less likely skin irritation than chemical UV absorber ingredients. The titanium dioxide particles used in sunscreens have to be coated with silica or alumina, because titanium dioxide creates radicals in the photo catalytic reaction. These radicals are carcinogenic, and could damage the skin.