Hey Sallie, The American Cancer Society has Hair Dye and Cancer Risks article. It looks like the jury is still out. I use Nice and Easy. I don't like using it, but I just look so washed out otherwise. My hairdresser said it's safe. Anyway, I leave it on only for the alotted time. I rinse well. I try to go as long as possible between treatments. One lady's on here did say that a doctor at Dana Faber told her that hair dye does absorb through the scalp. So if you're one of those people that look fabulous with grey or silver hair, skip the dye. We should wait 6 months or longer after getting traditional chemo to dye our hair. Since our hair is very fragile then💜