Late last year, stylists in the US state of Oregon complained of eye irritation, nosebleeds and breathing issues after repeatedly applying Brazilian Blowout, a liquid keratin straightening treatment.
Oregon's Occupational Safety and Health Administration tested 105 samples of various hair-smoothing products and found unsafe amounts of formaldehyde in all but three brands of them.
The presence of formaldehyde is significant, says Arthur Grollman, a science professor at Stony Brook University School of Medicine.
"My concern is that formaldehyde is a probable human carcinogen that should never touch your skin or anything else," he says.
But despite the nasty buzz on the expensive process, many women seem to think that good hair trumps bad chemicals.
"Am I nervous about the chemicals?" Cohen asks. "Sure. But I'm not willing to give it up." However, at Cohen's last application several weeks ago, the technician wore a mask and gave her one.
At the DeFranco Spagnolo salons in New York Brazilian Blowout is used despite the controversy.
Owner Anthony DeFranco says, "My concern is not so much for the client who only gets it done two or three times a year, but for the stylist who's applying it sometimes two or three times a day. The salon has created a specially ventilated room, and requires masks for both stylist and client. But DeFranco says straightening products "all contain formaldehyde. If they don't, they don't work."
As a fan of the Brazilian Blowout process, what does all the bad news mean to Cohen? "Everyone who does it is uncomfortable with it, but it's like what you do for beauty. I'm still going to do it ... because it works."
Allure magazine has long been covering the Brazilian hair-straightening controversy. In 2007, the beauty publication reported on several salon solutions that contained high levels of formaldehyde, and, just this month, ran a story called Hair Alert.
"These really scary symptoms resparked the issue," says beauty editor Heather Muir, referring to the Oregon stylists. Muir says that using the product is "a lot like when women say 'I feel prettier when I'm tanning'."