β-Carotene

At the start of last summer this was one of a set of beautiful un-bleached organic cotton waffle towels for use by guests at our guest house. It, along with the rest of the set have all been washed countless times and hung out in the bright Greek sun for hours and hours and hours since they last saw guests in 2014. I cannot put these out for guests looking like this, they have had to be replaced. It's not as though I am an incompetent launderess, I have no bother at all getting red wine out of muslin curtains. These towels have been trashed by folk who feel it necessary to paint themselves orange while they lie in the sun.

β-Carotene can be used as an oral supplement for periods of 10 weeks or greater to provide sun protection, it does not have to be spread on one's body. 

Now I shall have to resort to bleaching my towels. I wonder what effect that will have on our guests' skin.