If you love glossy, pin-straight locks, but were born with natural curls, you know it's a drag to juggle blow dryers and flat irons to get the style you're after. This makes in-salon Brazilian keratin treatments—which promise to liberate women from hair serums and hot tools—even more appealing. Stylists claim the process (that costs up to $500 with results up to four months) tames even the unruliest of manes. But the keratin treatment craze hasn't been completely controversy-free. This past fall, government reports and warnings put a serious crimp in the hottest hair trend in years: the treatment that vows to transform your tresses could be hazardous to your health.
How Brazilian Keratin Treatments Work
The Brazilian keratin treatment involves soaking the hair with a cocktail of keratin and oils to form a hard outer shell around the cuticle, which helps strands hold their new shape. The treatment works on all types of hair—even damaged or chemically treated tresses. Plus, there's plenty of wiggle room in terms of results. Depending on the brand, you can completely straighten your hair or dial down frizz without sacrificing volume, says Dror Kraft, a stylist and treatment specialist at Pierre Michel Salon in New York City, who has been performing the service for several years. Sounds good, right?
Formaldehyde: The Toxic Chemical Culprit
Don't rush to your hairdresser quite yet. Because the solution doesn't technically alter the texture of hair, it locks in the temporary straightening results with formaldehyde—a chemical used in low levels in household cleaners, hand soaps, glue, and synthetic fabrics. "In higher concentrations formaldehyde can cause respiratory problems, skin allergies and irritation, and sometimes even cancer," says Richard Parent, a board-certified toxicologist in Damariscotta, Maine. "And most—but not all—salon keratin treatments produce varying amounts of it," says Wilson. Formaldehyde is released during the final stage of the process. Once a keratin-based complex is applied, the stylist flatirons the hair, "freezing" the new texture into place. When that happens, the heat from the iron sends fumes into the air.