Warning: if you're a hairdresser (particularly a male hair dresser), working with hair dyes will increase your risk of developing bladder cancer. And those who use hair dye may be at risk for bladder cancer, too, as well as lymphoma and leukemia. (Also, the darker the dye, the riskier it is.) Which means that the Naomi Watts of the world might be safer than, well, Cameron Diaz that time Cameron Diaz went brunette. [Independent]
Yeah, I had read that "they" agreed the only carcinogenic dyes were the "progressive" ammonia salt based ones, like Grecian formula, and that the others were all safe.
Heck, if it is the pigment, I'm screwed, cause aside from using regular dye, I love me some color-depositing shampoos filled with brown pigments.