What ingredient in sunscreen discolors cloths when washed in water with iron?
The ingredient in sunscreen that causes clothes to discolor is known as, avobenzone. It causes this when mixed with minerals that are found in water. This can then lead to brown, rust-like stains on clothes. For more details you can visit http://laundry.about.com/od/removingmakeupstains/f/sunscreenstains.htm.