Reviewed by Laura Martin on August 16, 2016

Sources

Environmental Working Group: "Brazilian-Style Blowouts: Still Poisonous, Still in Salons."; Occupational Safety and Health Administration: "Hair Smoothing Products That Could Release Formaldehyde."; FDA: "Hair-Smoothing Products That Release Formaldehyde When Heated."; National Institutes of Health: "New Substances Added to HHS Report on Carcinogens."; American Academy of Dermatology: "Dermatologists’ top tips for maintaining smooth, shiny hair."

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Video Transcript

AREFA CASSOOBHOY: Visit a salon, and leave with smoother, shinier, or straighter hair that lasts for weeks. That's the promise made by Brazilian style blowout products. Just one catch-- they can be risky to your health. And here's why. When your stylist puts hair smoothing lotion that has formaldehyde in your hair, he'll usually heat it with a flat iron or a blow dryer. That can release formaldehyde gas into the air. And at unsafe levels, it could irritate your eyes, trigger allergic reactions, and even raise your risk for cancer.

Some lotions that claim to be formaldehyde-free may have ingredients that also can pose risks. So if you're wondering what's in a certain product at your salon, just ask. The safe move is to skip those Brazilian style blowouts. You've got other ways to smooth your do. Change up your hair products, and talk to your stylist.

For WebMD, I'm Dr. Arefa Cassoobhoy.