Racist beauty standards do a lot of damage to non-white women. The immense global pressure to conform to a white European ideal—including light skin, straight hair, and a slim figure—means that women of color are particularly susceptible to developing psychological problems ranging from eating disorders to depression and generalized self-hatred.

Now research suggests that racist beauty standards put minority women at higher risk of physical health problems, too. In a commentary published in the American Journal of Obstetrics and Gynecology, researchers from George Washington University and Occidental College argue that women of color are exposed to higher levels of toxins than white women. That’s because they use, on average, more cosmetic products in an effort to comply with European beauty standards.

“Racial discrimination based on European beauty norms can lead to internalized racism, body shame, and skin tone dissatisfaction, factors that can influence product use to achieve straighter hair or lighter skin,” the authors write. “Thus, beauty product use may be 1 [sic] way that structural discrimination becomes biologically embedded.”

The unregulated industry

In the US, cosmetics are largely unregulated by the Food and Drug Administration. Unlike drugs and medical devices, they don’t have to go through multiple clinical trials to be considered safe for consumer use.

However, the FDA does have a website where people can post complaints about various products when they experience adverse health outcomes. Between 2015 and 2016, the number of these complaints more than doubled, suggesting that some users think these products—especially hair-care products—are making them sick.

“Overall, cosmetics are very safe,” Shuai Xu, a dermatologist at Northwestern University’s Feinberg School of Medicine, told Quartz back in June. “But over the last 10 years, we’ve had controversy after controversy—mercury in skin lightening creams, for example, or Brazilian blowouts,” a hair treatment that produces formaldehyde, a known irritant and carcinogen, as a byproduct of some kinds of chemical straightening.

Any adverse health effects are likely to fall disproportionately on women of color, who tend to buy more cosmetics like makeup, lotions, and hair serums than white women—largely because of the societal standards that shame women who fall outside of the European ideal.

Minority women are also more likely to buy products that have been advertised specifically to help them appear more “white,” like skin lightening creams or treatments to chemically straighten their hair, says Ami Zota, an environmental epidemiologist at the George Washington University and co-author of the commentary.

Some of these products contain chemicals with known health consequences. Brazilian blowouts, which are straightening treatments, expose both those giving and receiving them to formaldehyde. The American Cancer Society says that the formaldehyde released during some hair treatments indoors is a potential health threat.

Hydroquinone, the active ingredient in skin lightening creams, can actually cause permanent skin bleaching, weakening of the skin, and even darkening of the skin in some cases. More worryingly, skin lightening creams that are popular globally are often made with mercury, a neurotoxin. Even though products with levels of mercury above one milligram per kilogram are illegal in the US, users often bring them back from travel abroad. In 2010, the US Centers for Disease Control found that almost 30 people living in California and Virginia had elevated levels of mercury in their blood as a result of illegal skin-lightening creams brought back from Mexico.

Gaps in cosmetics research

Although some of the chemicals in legal cosmetics appear to be safe in lab settings, these studies don’t account for how women actually use them. For example, a skin-lightening cream label may instruct users to put just a dab of lotion to lighten a dark spot. But women of color may be using the cream on their whole bodies.

It’s important to consider usage habits in order to quantify potential toxic exposures, says Tracey Woodruff, the director of the Program on Reproductive Health and the Environment at the University of California, San Francisco unaffiliated with the commentary. “Is it based on the average person, or the average Caucasian person?”

There’s also a gap in research about how some of the chemicals in cosmetics interact with other chemicals in the environment. When two chemicals are combined, they can create an effect called synergistic toxicity. Environmental racism means that low-income people of color are often more likely to live next to highways or factories, leading them to breathe in higher levels of air pollutants. If women in these communities are also using liberal amounts of products with potentially harmful chemical additives, the combined effect of these exposures could be even more detrimental.

Most of the women who buy cosmetics, including skin-lightening creams or hair straighteners, are between the ages of 18 and 34—which also happens to be period when women are more likely to have children. Zota thinks it’s possible that the extra chemicals in beauty products could be contributing to premature births or uterine fibroids—both of which are more common in women of color. For example, parabens, which are used as preservatives in makeup and shaving creams, have been shown (paywall) to act like extra estrogen in both men and women. But researchers are still trying to determine whether or not parabens could affect women’s reproductive health.

The difficulty with epidemiology is that it’s hard to track whether a particular chemical may cause an adverse health outcome. It’s always important to remember that correlation doesn’t mean causation.

But when it comes to a person’s health and well-being, it may be worth exercising caution even without damning data, according to Woodruff. Consider the evolution of research on smoking. Scientists started examining the link between smoking and lung cancer back in the 1930s (paywall), but it wasn’t until 20 years later that they performed larger, observational studies (paywall). In 1964, the US Surgeon General published a major report condemning smoking as a public health problem; today, tobacco is a known carcinogen.

The safest thing would be for women to stop using skin lighteners and getting their hair straightened. But the realities of racism put a lot of pressure on women of color to change their appearance. “Women who straighten their hair get better jobs and make more money. Women with lighter skin are more upwardly mobile,” says Bhavna Shamasunder, a professor of urban and environmental policy at Occidental College and co-author of the paper. Indeed, many women of color have publicly stated that they feel pressure to change their appearance to be more “professional”—essentially, to look whiter.

The power of consumer pressure

On the whole, Zota, Shamasunder, and Woodruff would like to see more disclosure from cosmetic companies about the ingredients in their products. Although there are some resources where consumers can look up the chemicals in their products, companies aren’t legally required to release information about the full content of cosmetics. Additionally, doctors treating women of color need to be aware that their patients may have more toxin exposure than their white patients. If health-care professionals remember to ask patients about their beauty regimens, they have an opportunity to warn them about potential chemical harm.

Although changing cosmetic regulation may take years, consumer pressure can quickly do what cumbersome legislation cannot. Back in 2014, Johnson and Johnson announced (paywall) that they removed any traces of formaldehyde from their baby shampoo—despite the fact that the chemical had never been in high enough concentrations to have been proven to cause any harm to any infants. Woodruff thinks that a similar pressure from consumer groups—particularly on behalf of women of color—could cause cosmetic companies to reformulate their products to remove some of these chemicals.

“Our standards of beauty are another way that we’re perpetuating racism,” says Zota. And racism has a very real impact on minority women’s health.