"tip for the day" for 28th January drew attention to the risks between hair dye use and bladder cancer. I have gone grey prematurely , having had M.E./ CFS for so long. I have been using a "tone on tone" hair colourant made by L'Oreal, called "Casting" for some time now, every 18 days, or thereabouts. L'Oreal, of course will not admit to any risks of bladder cancer for users of their products, especially as "Casting" is not at the most powerful end of their product range. But still, I feel somewhat anxious, as I have had problems with my bladder. Do you have any knowledge about the risks of "tone on tone" colourants; are there any?!