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The FDA proposed a ban on hair straightening products containing formaldehyde that may cause cancer. Catherine Falls Commercial/Getty Images
  • The FDA has proposed banning hair straightening products containing formaldehyde, a known human carcinogen.
  • The cancer-causing effects of hair relaxers containing formaldehyde disproportionately affect Black women.
  • A recent Reuters report shows that thousands of Black women filed lawsuits against cosmetics companies claiming their hair-relaxing products caused uterine cancer.
  • If approved, an FDA ban on formaldehyde-based hair products could take effect by April 2024.

The U.S. Food and Drug Administration (FDA) may soon propose a ban on formaldehyde hair straightening products that contain or emit the chemical.

Formaldehyde, a colorless compound commonly used in germicides and disinfectants, is a known human carcinogen, meaning it can potentially cause cancer.

According to the FDA, certain hair smoothing products release formaldehyde gas into the air when heated, which can lead to both short and long-term adverse health effects, including:

  • respiratory issues
  • asthma
  • cancer

The cancer-causing effects of hair straightening and relaxing products disproportionately affect Black women.

The FDA proposed a rule that, if approved, would ban formaldehyde-based hair products as soon as April 2024.

“This proposed rule would ban formaldehyde (FA) and other FA-releasing chemicals (e.g., methylene glycol) as an ingredient in hair smoothing or hair straightening products marketed in the United States,” the FDA states.

According to Dr. Christopher Bunick, PhD, a Yale Medicine dermatologist, an FDA ban on these products would be a major achievement in keeping consumers safe from carcinogens used in over-the-counter products.

“I sincerely hope lawmakers in Congress continue to fight for improved quality control in the manufacturing of over the counter personal care products,” he said.

Certain hair straightening or smoothing products release formaldehyde when they’re applied to the hair and processed and sealed with a heat treatment.

“The heat releases formaldehyde as a gas,” explained Michael T. Kleinman, a professor of environmental toxicology at the University of California, Irvine.

According to the FDA, salon professionals and customers risk inhaling these harmful fumes if a salon is not properly ventilated.

“In workers with high levels of exposure, formaldehyde is associated with myeloid leukemia and cancers of the paranasal sinuses, nasal cavity, and nasopharynx,” Kleinman added.

In the short-term, formaldehyde exposure can lead to irritation of skin and airway membranes, which can trigger asthmatic reactions and other breathing problems, said Kleinman.

The greater the exposure, in regards to both concentration and duration, the higher the health risks, the FDA warns.

Evidence has been building for years demonstrating the potential harms of formaldehyde-releasing hair products.

Frequent use of formaldehyde hair straighteners, relaxers, or pressing products in the past year — at least four times a year — is also associated with a significantly increased risk of ovarian cancer, research shows. Long-term use of formaldehyde-based products is also linked to a higher risk of breast cancer and uterine cancer.

The health risks are greatest among Black women due to higher use of these products, evidence consistently shows.

One study published in 2021 found that 3% of non-Hispanic white women reported hair straightener use during adolescence compared to 75% of Black women, Kleinman highlighted.

Another study published in 2022 shows the first epidemiologic evidence of an association between hair straightening product use and uterine cancer.

This study was central to a recent Reuters investigation on the effects of hair relaxer products on Black women.

The investigation reports that thousands of lawsuits were filed against cosmetic companies by Black women who claim that chemicals in hair relaxers may release formaldehyde when heated and raise the risk of uterine cancer. The report indicates the companies, which include L’Oreal and Revlon, have denied the allegations.

Healthline could not immediately reach L’Oreal and Revlon for comment, but both companies told Reuters their products undergo rigorous safety reviews. “We do not believe the science supports a link between chemical hair straighteners or relaxers and cancer,” Revlon told Reuters.

“There is evidence that products containing these chemicals are disproportionately found in hair care products marketed to Black women, which wrongly reinforces healthcare disparities,” Bunick said.

“There is more scientific evidence connecting the use of formaldehyde and formaldehyde-releasing chemicals with cancer, in particular uterine cancer as well as breast cancer,” Bunick said.

Per guidance from the Occupational Safety and Health Administration (OSHA), any product that contains or can release formaldehyde needs to say so on its packaging.

To identify products containing harmful formaldehyde-related chemicals, look for the following ingredients:

  • formaldehyde
  • methylene glycol
  • formalin

“Consumers can immediately evaluate their products in the store before purchase, and avoid those products with formaldehyde or formaldehyde-releasing chemicals,” Bunick said.

Sometimes formaldehyde isn’t explicitly listed on the packaging label, and, in certain circumstances, there may be other chemicals that, when heated, can release the carcinogen.

For example, chemicals that are synonyms for formaldehyde include formalin, methanal, methanediol, or formaldehyde monohydrate, according to the OSHA.

Chemicals that release formaldehyde when heated include, but are not limited to, timonacic acid, dimethoxymethane, or decamethyl-cyclopentasiloxane.

More examples can be found here.

You can also ask your salon professional if the products they use contain formaldehyde or if there’s an ingredient list you can look at.

Many salons have alternative hair smoothing products that don’t release formaldehyde when heated.

More research is needed to understand which products may be harmful — personal care products should help, not harm, people, Bunick said.

“There is an important movement in medicine today to make sure all people, regardless of skin color, race, or ethnicity have equal access to timely and quality health care,” he said.

The U.S. Food and Drug Administration may soon ban hair straightening products that contain or emit formaldehyde.

Some hair smoothing products release formaldehyde gas into the air when heated, leading to short- and long-term adverse health effects, including respiratory issues, asthma, and cancer.

If approved, the proposed rule would ban formaldehyde-based hair products as soon as April 2024.