As Sara (name has been changed), a 38-year-old Hollywood costume designer, strapped on her military-grade rubber gas mask, she looked at her hair: waist-length, perfectly highlighted—but hopelessly dry, frizzy, and brittle. "This is going to be worth it," she said, watching her friend Karen (named has been changed), a fellow costume designer with similarly damaged hair, secure her own mask. The women had cut off the tops of their masks—$700 each, ordered from a crime-busters website—so their hair could come through.

They sat on Karen's balcony, a fan blowing over their heads, as the hairstylist they had hired fastened his own mask and snapped on a pair of latex gloves. Carefully, he began painting a noxious-smelling straightening solution all over their hair, then clamped it in a hot iron. Even with the masks, "The fumes were just awful," Sara says. "It was unbearable," Karen remembers. "My eyes and mouth burned." Both women endured the treatment because of the results they anticipated—and got. "We now have shiny, straight, beautiful hair," Sara says. "People even stop us on the street to comment on it."

The women were performing a home version of the latest salon blockbuster, which came to the United States from Brazil. Not since the Japanese thermal treatment five years ago has a hair-straightening product generated such buzz. Often referred to as escova progressiva (progressive blow-dry) in Brazil, it promises glossy, sleek but voluminous locks—even on color-treated hair—for two to three months. Brands in the United States include the Brazilian Keratin Treatment, from M&M International, and the Brazilian Blowout, offered by the Argyle Salon & Spa in Los Angeles.

The treatment, which costs between $150 and $600, has been added to the menus of a growing number of major salons across the country and many smaller establishments owned by Brazilians living in the States. Newspapers have jumped on the story: The New York Post announced that it's "replacing Japanese straightening." And The New York Times quoted an ecstatic hairstylist: "We're talking revolution."

But what people aren't gushing about is exactly how the formula works, what is in it, and why it can smell so noxious. The answers to these questions boil down to one word: "formaldehyde." It's a substance that is classified as a known human carcinogen by the International Agency for Research on Cancer, part of the World Health Organization. In other words, it can cause cancer.

Only one article mentioned formaldehyde: The New York Times', which included a quote from a magazine editor suggesting prospective clients ask their hairstylist where the solution comes from. But the misinformation about this treatment is so extensive, a simple query isn't enough to confirm safety. Allure collected samples of the treatment solution—from various hairstylists, salons, and one manufacturer—and sent them to an independent FDA-registered lab for testing. (Although they both declined to provide us with samples, the John Barrett Salon at Bergdorf Goodman in New York City—which had just begun offering it—suspended the treatment while they tested their solution themselves, and the Frederic Fekkai salon in New York City put its plans for the service on hold while it evaluates the treatment's safety.) The results of the lab tests were surprising.

The samples we tested contained at least ten times more formaldehyde than the .2 percent that is determined to be safe by the Cosmetic Ingredient Review Expert Panel (CIR), a group of scientists and doctors who assess and set recommended safety standards for cosmetics ingredients. The formaldehyde concentrations in the samples ranged from 3.4 to 22.1 percent. The latter batch, with formaldehyde that totaled over 100 times more, was not from a U.S. salon. (It was one of two solutions from Sara; she buys them directly in Brazil.)

Small amounts of formaldehyde are found in household cleaners, synthetic fabrics, carpets, plywood, tobacco smoke, and smog, and are generally believed to be harmless. And while skin contact can cause hives and other minor irritations, inhaling the chemical is the real danger: Once the Brazilian straightening solution is painted on dry hair—stylists try to avoid the scalp—the stylist flatirons the hair, releasing vapors into the air. With repeated inhalation at higher levels, formaldehyde is associated with nasal and brain cancer, and possibly leukemia, according to the National Cancer Institute.

Noting that no one has done any serious safety study on this treatment, Mort Westman, a cosmetic chemist and president of Westman Associates, says, "I would not personally use this product." He has evaluated the treatment on his own. "It contains enormously high levels of formaldehyde compared to CIR recommendations and poses an unknown risk."

OUT OF THE MORTUARY

The treatment's origins have their own urban legend: Rumor has it, the process was born when an embalmer in Brazil found that the formaldehyde he used on corpses also straightened their hair, according to Los Angeles hair colorist Tracey Cunningham, who hasn't performed the service but has heard the story several times from Brazilian clients. The embalmer allegedly reasoned, Why wouldn't it work on the living? And with a hairstylist, he created a solution thought to have a formaldehyde percentage in the 20s.

Even in Brazil's humid, tropical climate, treated hair stayed smooth and silky for two to three months. Some manufacturers began diluting the formaldehyde for customers who complained that it irritated their eyes and nose.

Then, in March of this year, a 33-year-old housewife in Brazil died after using escova progressiva, which she applied herself and left on her hair for four days, the amount of time salons recommend. Anvisa, Brazil's National Health Surveillance Agency, wasn't able to find a link, but it was a theory at one time that the treatment may have caused her death. "She was an otherwise healthy woman," says Vanessa Amaral, Anvisa's press secretary. "What we thought possibly happened was that after doing the treatment, she was in the bathroom taking a shower, and the heat caused the fumes to release. And she asphyxiated herself, and it led to a heart attack. She died in the shower."

Soon after the woman's death, Anvisa redoubled their efforts to enforce their ban on all products that contained more than .2 percent formaldehyde. The trouble is, at that low concentration, "the treatment probably isn't effective at all," Westman explains. Most stylists claim that the creamy protein keratin, which is also in most versions of the treatment, is what straightens hair. But "in my opinion, it's doubtful that keratin does anything other than provide a good marketing story," Westman adds. "It's window dressing. It's really the formaldehyde that makes the treatment work. Once the hair is saturated with the solution and brushed straight with a hot iron, formaldehyde changes the bonds in the inner cortex of the hair and then fixes that configuration to give it semipermanence."

A black market for versions of the treatment with banned levels of formaldehyde soon sprang up in Brazil. Believing that Brazilian authorities would never actually enforce the law, many hairdressers continued to perform the treatment. "It is forbidden to use above .2 percent in Brazil because it's so unhealthy," Amaral says. "Our job is to control it, but it's very difficult to stop. When we send agents to the salons, they hide everything." The illegal treatment still flourishes.

HITTING HOME

Last November, treatments containing varying strengths of the solution started to show up in the United States. Using a mixture he buys directly from Brazil, hairstylist Mauricio Ribeiro was an early adopter, performing it at the Argyle Salon & Spa. Other top salons followed. To date, there have been no public reports of adverse side effects in the United States. Westman is encouraged by that but says that the adverse effects of overexposure to formaldehyde may not manifest themselves as a medical problem for several years.

The logical question seems to be: Why is this treatment being performed without conclusive information about its safety? No health agency has deemed it illegal in the United States—but that's because no group approves beauty products before they come to market. "We don't regulate ingredients in cosmetics except for color additives," says Veronica Castro, a spokeswoman for the Food & Drug Administration. But that does not mean the Brazilian hair treatment is approved by them. "The fact that the FDA doesn't regulate this product doesn't mean they have deemed it safe," says John Bailey, executive vice president for science at the Cosmetics, Toiletries and Fragrance Association (CTFA), a trade association for the cosmetics industry. "It just means the FDA hasn't looked into it to establish a limit. The primary responsibility rests with the manufacturer to introduce a safe product."

The one government agency that does regulate formaldehyde does so to protect the people who work with it. The Occupational Safety & Health Administration (OSHA) limits the exposure to formaldehyde in the air at .75 ppm (parts formaldehyde per million parts of air, measured over an eight-hour exposure)—which can only be verified by monitoring the air. OSHA did not respond to calls on this topic, but Virginia Richards, a pathologist at New York University Medical Center who uses formaldehyde every day in the lab, described the safety standards in her industry. "We work under a ventilation hood that continually monitors formaldehyde indirectly by insuring adequate air-flow rates—if rates drop below the appropriate level, an alarm sounds and the ventilation can be improved," Richards says. "More formally, formaldehyde is measured semiannually by placing absorbent badges on pathologists during a normal workday and measuring the amount of formaldehyde absorbed by the badge over an eight-hour period. The formaldehyde fumes absorbed by the badge are then quantified by gas chromatography." Michael Katz, a chemical engineer who specializes in environmental toxins and federal regulations, says, "Many embalmers don't use formaldehyde anymore because it's so toxic. It can kill people, quite frankly."

The only way OSHA regulates liquid formaldehyde is to require any solution with greater than 1 percent to carry a warning label. The only bottle we saw with one came from M&M International, which supplies their Brazilian Keratin Treatment to salons. Its labels read: "Warning. This product contains formaldehyde, which is a potential human carcinogen. Its exposure should be avoided by women who are pregnant and/or breast-feeding. Avoid contact with skin, scalp, and eyes. Do not inhale fumes. Both professional and client must wear protective clothing. Keep out of reach of children." But clients rarely see the bottle.

RISKY BUSINESS

Inaccurate information about the treatment is rampant among stylists and distributors. Some salon owners and stylists told us they believed that their solution contained 2 percent—not .2 percent—formaldehyde, and that it is actually approved by the FDA. ("That's false," says the FDA's Veronica Castro.) One chemist spoke on condition of anonymity, saying, "If what they say is true, the salon professionals are being fed false information, which they are innocently passing on to the consumer."

Most stylists said they use some precautions, like wearing latex gloves and working near open windows. "That may not be enough," says cosmetic chemist Ni'Kita Wilson, director of research and development for Cosmetech Lab in New Jersey. "The person most at risk is the beautician because she is using the product regularly, and thus has more exposure. She should consider at least wearing a mask, but that would freak out the client." Plus, according to Katz, OSHA says that the perception of formaldehyde by odor and eye irritation becomes less sensitive with time as you adapt to it, which can lead to overexposure.

In a training video that she sends to any salon that buys her formula, Marcia Teixeira, founder of M&M International, shows both the client and stylist wearing white dust masks during the company's Brazilian Keratin Treatment, but Westman notes that "it is highly questionable that those masks, which are intended to be effective against airborne particles such as dust or sawdust, would be adequate to prevent inhalation of the formaldehyde gas." When asked to respond, M&M International's marketing/sales manager Sofia Hintz said, "The masks are used in the industry much like painters use masks and nail technicians use masks. It should be something for OSHA or other entities to study. We try to follow guidelines established by the industry."

So is there a definite way to perform the treatment safely? Sara and Karen may have been onto something: "I suspect that there are respirator gas masks adequate to prevent inhalation of formaldehyde," says the chemist who spoke anonymously. "A quick Google search turned up a 3M respirator gas mask for $150."

The salon workers we talked to do not seem to be worried. "I've been to my doctor, and he said my clients and I have nothing to worry about," says Ribeiro of the Argyle Salon & Spa, noting that he wears latex gloves and works in a private room off the main salon with the windows open and a fan blowing to direct fumes outside. "None of my clients have told me of any bad side effects, only that they love their hair." Daniel Rosa, a hairstylist at Shampoo Avenue B in New York City who gives the treatment in a well-ventilated room, says, "I'm not worried at all. My clients and I both wear dust masks, and I'm always careful to position the fan so it blows the fumes away from our faces."

The only client we spoke to who said she knew her treatment could be unsafe was Sara—hence the gas masks and the outdoor, at-home application. She buys the solution while on trips to Brazil, pouring it into empty shampoo bottles and bringing it home in her suitcase. She and Karen have switched to a milder solution and have abandoned their gas masks, but they're still chancing it, since that solution, at 3.5 percent in Allure's tests, still far exceeds the established .2 percent formaldehyde safety level. "I don't care if it's bad for me. I now have the kind of hair I always dreamed about," says Sara, who has had 12 treatments so far. Karen, who has had eight treatments, finds gallows humor in the situation. After Sara gave us samples of their solutions for testing, Karen said, "When you guys get the test results back, let us know. We want to know how long we have to live."

WHAT HAPPENS NEXT?

Most women aren't likely to be so cavalier and may ask: What about secondhand formaldehyde fumes? And if it isn't the FDA's job to regulate cosmetics, will the treatment ever be guaranteed safe—or pulled off the market?

"Under law, the FDA mandates that cosmetics must be safe," says cosmetic chemist David Steinberg, author of Preservatives for Cosmetics (Allured Publishing Corporation). Yet how would they know a product is unsafe if they don't investigate it? "The way it works is something bad or suspicious has to happen first," says CTFA's John Bailey. "The FDA needs to be shown evidence a product is unsafe, through injury or consumer complaints."

After learning of the treatment when Allure contacted them, the FDA requested a copy of the formaldehyde test results from the independent lab. Their response: "The FDA is concerned about ingredient and product safety and reviews data that is made available to us," says Linda Katz, director of the office of cosmetics and colors for the agency. "If the FDA determines that a health hazard exists, the agency will advise the industry and the public, and will consider its options under the authority of the Federal Food, Drug, and Cosmetic Act in protecting the health and welfare of consumers." Time will tell if they take any regulatory action.

BLACK MARKET BEAUTY

Although most salons told Allure reporters that they believed the treatment was safe and regulated, some—especially the ones owned by Brazilians who may well know about the ban on the product in their homeland—seemed to be aware that they were doing something questionable. A few we called offered us escova progressiva in its original strength, but only after hours, or in warehouses, private homes, and obscure, hole-in-the-wall spots. When an Allure reporter, posing as a client, called several salons and asked for "the real thing from Brazil," the responses came in low, hushed voices: "I've got what you want," said on New York City salon technician. "Can you meet me at 9 p.m. Friday? I'll let you through the back door." Whispering, another said: "Wait by your phone. I know someone who's got what you need."

Lab Report

Allure asked a manufacturer and three salons for samples of their Brazilian hair-straightening solutions. An FDA-registered lab found formaldehyde levels in excess of the Cosmetic Ingredient Review's recommended .2 percent limit.

THE SOURCE: M&M International, which makes the Brazilian Keratin Treatment and distributes it to United States salons.

FORMALDEHYDE LEVEL: 3.4 percent.

THE RESPONSE: "I don't know how the lab is measuring the formaldehyde, because I'm very careful to only use 2 percent," says Celia Ferreira, a chemist with Pro Skin Solutions in Orlando, which makes the treatment for M&M. We asked her whether she still thinks 2 percent is safe even though the CIR recommends just .2 percent. Her answer: "The levels of formaldehyde are safe and accepted in many countries, including in the United States by the FDA. OSHA has supervised the application of the hair treatment and approved the process." ("OSHA does not supervise or approve the manufacture or application of consumer products," says a departmental spokesperson for OSHA; Ferreira did not get back to us with a response by press time.) M&M International's marketing/sales manager, Sofia Hintz, says, "We care to pass on the safety guidelines established by the FDA and OSHA to the professionals who use our product. We are responsible enough not to sell our product unless the stylist is licensed, working in a salon, and has been trained and certified by us. All the materials used in a salon—ammonia, bleach, acrylic nail solution, relaxing solution, and so on—give off fumes and gases."

THE SOURCE: Spalano's Salon in Boca Raton, Florida.

FORMALDEHYDE LEVEL: 3.7 percent.

THE RESPONSE: "If I am using something dangerous, I am most certainly not aware of it," says hairstylist Fred Savage, noting that he buys his solution from M&M. "I had an OSHA representative here in the salon to do a ppm [parts per million] test, and she told me the levels were below what was acceptable." But in fact, when Allure requested records from OSHA, the investigator did not appear to reach that conclusion, instead only saying the salon owner told her they had "prohibited the use of that product. Apparently, a stylist at the salon brought the product in on her own," says the OSHA spokesperson. When an Allure reporter called three months after the investigation, the salon was still continuing to offer the treatment. In response, Savage said, "From everything they told me when they were here, the treatment was perfectly fine." The salon's owner was traveling and couldn't be reached for comment.

THE SOURCE: Argyle Salon & Spa in Los Angeles, which offers The Brazilian Blowout.

FORMALDEHYDE LEVEL: 5.4 percent.

THE RESPONSE: "I'm totally confident this procedure is safe. I do it properly and take all the right precautions. If I thought there were any safety concerns, I would never use it on my clients or myself," says hairstylist Mauricio Ribeiro, who buys the product himself in Brazil. The owner of the Argyle Salon & Spa, Britney Huinker, said, "The Argyle is surprised at these results and will look into further analysis of its formula and the testing techniques used by this lab. Our supplier has assured us that a 2 percent solution was supplied to the Argyle and that it is safe. We will further investigate this to verify it."

THE SOURCE: Shampoo Avenue B Salon in New York City.

FORMALDEHYDE LEVEL: 7.24 percent

THE RESPONSE: "I've learned firsthand how to properly apply the product by the inventor of the specific brand we use," says the salon's owner, Harley DiNardo, who declined to tell us the brand but noted it was a company in Brazil. "Our version of the treatment is washed out in the salon. No waiting three days like the others. That fact alone means that the client does not have to live with the chemicals in their hair—breathing it, sleeping with it—for three days. If done properly, there should be no cause for concern."