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Gel manicures are no strangers to controversy. The exposure to UV light that comes with curing gel polish has long sparked skin cancer concerns, though studies have largely concluded that the risk is low. Some of the ingredients in gel polishes are known to be skin sensitizers, which, if absorbed into the skin, may cause contact dermatitis or, over time, a type of allergic reaction called delayed hypersensitivity reaction.
And this week, the European Union raised an apparent new concern. On September 1, it announced a ban on gel polishes containing a specific ingredient—trimethylbenzoyl diphenylphosphine oxide (TPO)—after classifying it "carcinogenic, mutagenic, or toxic for reproduction." Effective immediately, gel polishes with TPO will no longer be legal to sell to consumers or use in salons across the EU.
Almost instantaneously, headlines inaccurately stating that Europe had banned all gel manicures popped up, quickly followed by fact-free fearmongering on social media. Some TikTok users have claimed, also inaccurately, that gel nail polishes in general contain “toxins” that are “causing infertility.” Others have suggested the US is derelict for not banning TPO. None of these things are true in the cut-and-dry sense, but the message has clearly instilled some fear of gel formulas on the internet. Before you decide to swear off gel manicures for good, you may want to understand how the EU reached its decision and how you can still safely proceed with your biweekly appointment should you so choose (spoiler alert: you likely don’t need to change a thing).
Meet the experts
- Kelly Dobos is a cosmetic chemist
- Mona Gohara, MD, is a board-certified dermatologist
- Amanda Lam is a cosmetic chemist
- Shyamali Singhal, MD, a board-certified surgical oncologist
To be perfectly clear, gel nail polishes and manicures themselves have not been banned outright in the EU—just trimethylbenzoyl diphenylphosphine oxide. Otherwise known as TPO, it’s a photoinitiator, aka a type of compound that turns liquids into solids when it absorbs energy from light. It’s commonly used in gel nail polishes because of its curing efficiency and resistance to yellowing, according to cosmetic chemist Kelly Dobos.
The EU first identified TPO as a substance of concern in the spring of 2024, Dobos says, and the toxicity data that raised those red flags primarily comes from animal feeding studies. Shyamali Singhal, MD, a board-certified surgical oncologist and medical director of the cancer program at El Camino Health in Mountain View, California, noted this as well. “Studies in animals—not humans—show that ingesting high concentrations of TPO leads to fertility issues,” she says.
The experts we spoke to believe it’s unlikely that a harmful concentration of TPO would ever get into the bloodstream when used as intended.
In other words, the EU determined that TPO should be deemed "carcinogenic, mutagenic, or toxic for reproduction” based on animals that ingested the ingredient in high concentrations. Dobos believes the EU is taking a hazard-based approach instead of a risk-based approach, which, in so many words, means she thinks the choice might have been made without considering how people actually use gel nail polish. She can explain a little further: “A risk-based method helps regulators decide if a product is truly unsafe in the way it's used, allowing for more nuanced decisions that protect public health while still allowing useful products on the market.” A hazard-based approach, on the other hand, looks at whether a substance could be dangerous based on its properties regardless of how people actually use it. “So even if there's little or no real-world exposure, ingredients might still be banned,” Dobos says.
This extra-cautious outlook doesn’t surprise those familiar with the EU’s approach to ingredient regulation. “The EU has been notorious for being more conservative with ingredient banning than other countries,” cosmetic chemist Amanda Lam says. “Some of the data that the EU references either uses larger concentrations than what is normal consumption or out-of-context use of the ingredient, like injecting an ingredient into the bloodstream directly versus applied topically.” In this case, the studies show something closer to what would happen if you enjoyed your gel nail polish as a nightly digestif, not what the effects of bi-weekly manicures would be.
There aren’t any American legislative or agency announcements addressing the ingredient yet—and some experts think there might never be. Can the U.S. Food & Drug Administration take other countries’ decisions into consideration? Sure. But it’s worth noting that it is, in fact, against the law for cosmetics to contain ingredients that could harm consumers when used as intended, and the FDA makes its own decisions based on “reliable scientific information available to us.”
That mostly explains why we don’t have a similar ban in effect already. “Different countries have different standards for chemical regulation, which can lead to varying decisions about the same ingredient,” says Connecticut-based board-certified dermatologist Mona Gohara, MD. “What this really shows is that more research is needed to fully understand TPO’s safety profile.”
Gel polishes containing TPO will likely continue being available in the US, but that doesn’t mean those who get gel manicures—and those who provide them—need to panic. The experts we spoke to believe it’s unlikely that a harmful concentration of TPO would ever get into the bloodstream when used as intended (as in, not eating it).
“It is doing a disservice to consumers to cause fear based on data that does not accurately reflect normal use of cosmetics.”
“TPO is applied to the nail, which is made of densely packed keratin, which is very hard to penetrate,” Dobos explains. Lam adds that once the nail polish cures under a UV light, there is no opportunity for the TPO to penetrate the skin as it “locks” into its solid state and deactivates. (That also means nail biters aren’t just eating pure TPO so long as their gel polish is properly cured.)
“In my opinion, there's not much reason to avoid TPO in a well-formulated gel polish,” Dobos says. Of course, everyone’s risk tolerance is different. “For those who are concerned, I would approach it the same way I advise people who are uneasy about chemical sunscreens: choose a product without those ingredients,” Dr. Gohara says. “There are reputable gel manicure brands available that do not contain TPO.” Dobos notes that those formulations typically use photoinitiators like ethyl trimethylbenzoyl phenylphosphinate (TPO-L, a modified form of TPO) and hydroxycyclohexyl phenyl ketone. (It’s worth mentioning, however, that as far as we can find, there are no similar studies indicating these ingredients are any more or less safe than TPO.) Although the EU rules don’t apply to the US, it’s possible we’ll see an increase in these alternative formulas anyway. For brands sold in both regions, it’s not exactly efficient (though also not unheard of) to make two separate versions of the same product.
Speaking of sunscreen, Gohara adds that the better-established cancer risk associated with gel manicures is not that of TPO but of UV light—but she still enjoys gel manicures herself. “Simple precautions can make a difference,” she says, regarding both UV and TPO exposure, like applying sunscreen to your hands before curing and using Vaseline on your cuticles to create a barrier where products may come into contact with the skin.
Ultimately, the experts we spoke to want people to keep a level head about gel manicures. “I understand the responsibility to keep people safe and am in full support of that, but I think the EU needs to be responsible with direct data to support that topically applying the nail polish and curing it has any impact on reproductive health,” Lam says, and there simply is no data suggesting intended use of TPO is harmful to humans. “It is doing a disservice to consumers to cause fear based on data that does not accurately reflect normal use of cosmetics.”
