• Health
  • toxins

Even ‘Non-Toxic’ Nail Polish May Contain Harmful Chemicals, Study Says

4 minute read

Cosmetics are subject to very few regulations in the U.S. While they fall under Food and Drug Administration (FDA) purview, current laws do not require beauty products and their ingredients to be FDA-approved before hitting shelves. Even laws that pertain to cosmetic labeling are somewhat loose; many buzzwords that show up on product packaging mean, effectively, nothing.

That’s also the case for many nail polishes. And even brands that tout safe formulations may be substituting some toxic chemicals for equally dangerous alternatives, suggests a new study published Wednesday in the journal Environmental Science & Technology.

“It’s sort of like playing a game of chemical Whac-A-Mole, where one toxic chemical is removed and you end up chasing down the next potentially harmful chemical substituted in,” says study co-author Anna Young, a doctoral student at Harvard University.

In the early 2000s, many nail polish companies began labeling their products “three-free,” to signify that they were made without dibutyl phthalate (a plasticizer used to enhance a polish’s texture and function, but that is linked to potential reproductive and developmental problems), toluene (a nervous system and developmental disruptor) and formaldehyde (a carcinogen). Since then, many brands have eliminated even more chemicals commonly used in nail polish, labeling their products “five-free,” “10-free” and even “13-free.”

But even with these labels, it can be difficult to determine which chemicals are actually excluded, and which have been added in their place. To find out, Young and her colleagues purchased and tested the contents of 40 nail polishes from 12 different brands, labeled three-free all the way up to 13-free. While the study did not name specific brands, the authors noted that two of the tested brands made up a combined 15% of the nail polish market.

“We found that the meaning of these claims isn’t standardized across brands, and there’s no clear information on whether these nail polishes are actually less toxic,” Young says. “Sometimes, when one known harmful chemical was removed, the polish instead contained another similar chemical that may be just as toxic.”

While most five-free polishes lacked the the same handful of ingredients, the researchers found far less consistency among polishes marked 10-free and above, and the brands varied in terms of how well they adhered to the claims on their labels.

None of the samples contained toxic dibutyl phthalate. But polishes with a range of labels tested positive for at least one of two other plasticizers shown to be similarly risky to health. One polish even contained a plasticizer it claimed to exclude from its formula.

While the sample wasn’t representative of the entire nail polish market, it did include some of the industry’s most popular brands. Young says that makes the findings relevant to anyone who wears nail polish, even though it’s not yet clear how much exposure it takes for these chemicals to affect a person’s health. The results are especially significant for nail salon employees, who are subjected to range of health risks and often poor working conditions.

“This is especially important for the over 400,000 nail salon workers in the U.S. who could be exposed on a daily basis, for many years, to chemicals that have been linked to health effects on fertility, the reproductive system, fetal development, thyroid function and possibly even obesity or cancer,” Young says.

An occasional manicure probably isn’t cause for major concern, Young says, but the study underscores the need for better transparency and consistency in the beauty world. She’s not alone in that belief: Senators Dianne Feinstein and Susan Collins last year proposed a bill that would update the Federal Food, Drug and Cosmetic Act to ensure the safety of cosmetics.

“These labels should try to be more standardized and validated by an unbiased third-party,” Young says. “It’s not as simple as what’s not in the polish; you have to address what’s still in the polish, or what’s being substituted in as a replacement chemical. We need more clear information and explanations of what these exclusions mean for health, and whether they actually reduce the overall toxicity of the nail polish.”

More Must-Reads from TIME

Write to Jamie Ducharme at jamie.ducharme@time.com