(CBS) Brazilian Blowout, you are officially on notice.
The FDA sent a scathing letter to the popular hair-straightening brand, saying its product could endanger consumers and hair stylists who use them.
The letter called the Brazilian Blowout Acai Professional Smoothing Solution "adulterated," with the liquid methylene glycol. When heated with a blow dryer and hot flat iron, the liquid releases carcinogenic formaldehyde vapors into the air.
People exposed to large amounts of formaldehyde in their professions are at an increased risk for lymphoma, leukemia and brain cancer, according to the American Cancer Society.
An FDA analysis of Brazilian Blowout samples found formaldehyde levels ranging from 8.7 to 10.4 percent. The government requires an occupational hazard alert if levels are 0.1 percent or higher.
What's more, the product is "misbranded," says the FDA, since its label reads "No Formaldehyde" or "Formaldehyde Free." The agency called those statements "false and misleading."
"The failure to include information about the release of formaldehyde into the air during the heating process on the product's label or labeling makes your product misbranded because you fail to reveal material facts with respect to consequences that may result from the use of your product ," the letter read.
The agency threatened an injunction or seizure of products if Brazilian Blowout does not say how it plans to address these allegations within 15 days.
The Environmental Working Group hailed the FDA's decision. The Washington D.C.-based advocacy group conducted its own investigation this year and found 16 products, including Brazillian Blowout, contained high levels of formaldehyde.
"FDA's recent action is a critical first step to getting this dangerous and very popular product off the market," Jane Houlihan, the group's senior vice president for research, said in a written statement. "Now FDA must apply the same pressure to the other companies that also peddle similar products laced with the cancer-causing chemical formaldehyde."
When reached by CBS News, a Brazilian Blowout representative had no comment.
If these products are so dangerous, how are they even on the market?
"If consumers have been wondering why they've still been able to get Brazilian Blowouts despite so much troubling news, the answer is because our regulatory system is broken," Anuja Mendiratta, a representative of the California Healthy Nail Salon Collaborative, said in a statement emailed to CBS News. "Even when a product has clearly been shown to poison people, the FDA has little authority to take immediate meaningful action in the case of cosmetics."