The Brazilian Blowout—a hugely popular salon treatment that transforms curly, frizzy, or damaged hair into smooth, shiny strands for up to three months—claims to be formaldehyde free. Not so, according to Oregon Health and Science University, which detected that the formulas were 4.85 percent to 10 percent formaldehyde, a probable carcinogen.
The university tested this particular brand because a Portland, Oregon hair stylist sent in the formulas for testing after she developed nose bleeds, eye irritation, and breathing difficulties. But the chemists warn that you should be just as weary of other similar “formaldehyde-free” brands. Any formula strong enough to change the hair’s texture like this has to use a chemical, and that chemical is most likely formaldehyde in some form (it’s often referred to as aldehyde, methanal, formalin, or methyl aldehyde).
Although limited exposure may not be that harmful to you, it could be making stylists who use the products regularly very sick. So before you go in for any treatments in the salon, be sure to ask about what products they are going to be using in your hair and ask to read the labels!