The company Green Chemicals says salon and at-home hair dyes that millions of people use contain chemicals linked to cancer.
Green Chemicals says the secondary amines in permanent dyes can penetrate the skin and stay on the hair for months or even years, and it can react with tobacco smoke and other pollutants in the air to form a powerful cancer-causing compound called nitrosamines.
It’s not clear how big of a risk this could be and the cosmetics industry strongly disputes the claim.
In the past, hair dye has been linked to breast, bladder, ovarian and brain cancers.
Green Chemicals is planning to launch a “safe” line of products soon.