A Brazilian Keratin Treatment is a hair-straightening process that uses keratin instead of chemicals to straighten hair. The keratin – a protein high in sulphur and cystine that is the foundation of hair and nails – is combined with formaldehyde (a carninogen) to form the straightening solution. The solution is fused onto the outer layer of hair with a 450-degree-Fahrenheit flat iron to create silky, smooth hair that lasts for three months. The process is effective in straightening hair; however, the formaldehyde in the solution poses health dangers.


Brazilian Keratin Treatment kits used by hair salons are not approved by the U.S. Food and Drug Administration (FDA) nor are they regulated by any other body. This means that there is no standard to what goes in the solutions, nor are they tested for safety.

Carcinogenic Properties

The main danger and health concern with Brazilian Keratin Treatments is the risk of cancer as formaldehyde has carcinogenic properties. According to the Cosmetic Ingredient Review (as reported by Style Magazine), only .02 percent of formaldehyde in cosmetic products is considered safe. Reports The Beauty Brains website, some Brazilian Keratin Treatments have been found to have up to 10 percent formaldehyde, the Cosmetics, Toiletries and Perfume Association said.

When the formaldehyde is heated by the straightening iron it vaporizes. The customer and the person applying it (plus those in the vicinity) are then exposed to high levels of formaldehyde gas, putting them at risk for cancer.

Other Health Dangers

Formaldehyde is known to cause other health issues such as eye irritation. It can also irritate the lungs if a person inhales formaldehyde fumes, which are created when the straightening iron is applied atop the solution.

Lastly, the formaldehyde slowly leaves the hair so the person with the treatment is exposed to it for up to three months. Every time that person uses a hot straightening iron to her hair, she exposes herself to the same risks (cancer, eye and lung irritation) as when she first had the process done.