Why Formaldehyde in Hair Straightening Products Is Dangerous

The Food and Drug Administration (FDA) proposed a ban on hair straightening products or relaxers that contain or release formaldehyde, a harsh chemical that’s linked to long-term adverse health effects and cancer.

The proposed ban came after a 2022 National Institutes of Health study showed a strong connection between the frequent use of chemical hair straighteners and uterine cancer.

Women who never used hair straighteners have a 1.64% risk of developing uterine cancer by the age of 70, but the risk increases to 4.05% for frequent users. The researchers said that Black women may be more affected because they tend to use these products frequently and start at a young age.

Studies have also linked the use of chemical hair straighteners to increased risks of ovarian and breast cancer.

“I commend the FDA for taking steps to protect people from the potential harms of chemicals in everyday personal care products,” said Christopher Bunick, MD, PhD, an associate professor of dermatology at the Yale School of Medicine. “This narrative keeps occurring, and it is time for action.”

Formaldehyde is a colorless, flammable gas at room temperature. When it’s present in the air, some people may have watery eyes, irritated nose and throat, coughing, wheezing, and skin irritation.

Over 150 chemical hair-straightening and hair-smoothing products contain formaldehyde, according to the New York State Department of Health. The labels are also unreliable: some products that are labeled “organic” or “formaldehyde-free” may also contain formaldehyde.

“Personal care products should help, not harm, the consumer, and there needs to be more study and more clarity over which products are helpful for which people,” Bunick said. “In this case, removing harmful carcinogens from products used disproportionately by Black women is absolutely necessary for their health.”

Are There Safer Alternatives for Hair Straighteners?

The FDA ban is only a proposal at the moment, meaning products containing this harmful chemical are still available on the market.

Bunick recommends speaking to your stylist before opting for a hair treatment and reading product ingredient labels.

“But there’s a catch,” he said. “Different companies may list the same product ingredients differently on the label, making it harder for consumers to understand what they are purchasing.”

For example, methylene glycol and formalin are just liquid forms of formaldehyde. Bunick said formaldehyde is sometimes listed as formaldehyde monohydrate, while methylene glycol could be listed as methanal or methanediol.

Terri Rehkopf, a Texas-based hairstylist and owner of Ippodaro Salon, said she uses an organic hair smoothing system called Oway Hstraighten to produce a semi-permanent hair straightening effect without damaging or irritating the hair and scalp.

“Another option is to start to embrace your natural curls, with guidance from your stylist on how to take care of your curls,” Rehkopf said. “The best thing to do is learn about best products for your curls and hair type.”