Colour me carcinogenic?

Have you always wanted to go from mousy brown to ravishing red? You're not alone: more than 50 percent of women in North America colour their hair, either in salons or at home.

Some consumer-safety groups have raised concerns about ingredients commonly found in hair dyes. Most hair dyes contain ingredients that are known or probable carcinogens. These potentially cancer-causing ingredients include HC Red No.3, lead acetate, m-aminophenol, and toluene-2. Some of these chemicals have been linked to breast and bladder cancers.

Case control studies have shown that hair dressers, who are occupationally exposed to hair dyes, have an increased risk of bladder cancer. A research study from the Dartmouth Medical School, published in the International Journal of Cancer (April 2004) suggests that women who dye their hair at home may also be at a higher risk for bladder cancer. The risks increased the more frequently they dyed their hair and the longer they'd been using hair dyes.

L'Oreal's Research and Development department, however, has recently published a study which concludes that "consumer or professional exposure to hair dyes poses no carcinogenic or other human health risks." L'Oreal netted a 1.65 billion profit about $2.7 billion Canadian from sales of cosmetics such as hair dyes in 2003.

While the scientific jury is still out on the safety of hair dye, you might want to choose henna- or herbal-based dyes, available at health food stores, which don't contain the suspect chemicals.