Why did the EU ban gel nail polish? 3 things to know

Many people love gel nail polish for its durability and shiny gloss, but a new ban in Europe may have left mani-pedi devotees with some not-so-pretty concerns.

On Sept. 1, the European Union banned one of the key ingredients from being manufactured, sold or commercially used. Nail technicians in salons across the continent need to dispose of polishes containing trimethylbenzoyl diphenylphosphine oxide, or TPO, and switch to alternatives.

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The chemical was classified as “carcinogenic, mutagenic, or toxic to reproduction” by European regulators after it was found to have reproductive toxicity effects in animal studies. In the United States, TPO remains legal and unrestricted in its use and sale.

So is gel nail polish safe to use?

Experts told PBS News that the amount of exposure to TPO that people experience with gel nail polish is very low, and that most applications of the beauty product put the user at minimal risk of the harmful effects found by the animal study.

“Every ingredient at some point is going to cause harm. It’s just a matter of dose,” said Michelle Wong, chemistry P.h.D and science communicator at Lab Muffin Beauty Science.

Here’s what you need to know about the safety of TPO and gel nail polish.

What is gel nail polish?

Gel nail polish is known for its long-lasting shine and quick drying time in comparison to regular nail polish. When cured under a UV lamp, acrylic polymers form, coming together as a film on the nail. This transformation occurs with the help of a photoinitiator like TPO.

“In the gel polish, it’s all broken up into smaller chunks, … and the photoinitiator is what starts the chain reaction that makes them all join up,” Wong said.

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Gel nail polish was invented in the 1980s alongside the introduction of UV lights for nails. The product has become a favorite for many nail salon customers, with a global market value of nearly $6 billion in 2024, according to one estimate. Some consumer brands now offer at-home gel nail kits complete with curing lamps.

Why did the EU ban gel nail polish?

The animal studies referenced in the ban found that when the animals ingested high levels of TPO, they experienced fertility and reproductive health issues.

That kind of exposure is completely different from what happens when humans typically apply gel nail polish, said Julian Sass, a cosmetic scientist.

“In isolation, this ingredient can be harmful when it’s fed to rats,” but it’s important to ask what the exposure looks like in real life, Sass said.

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Realistically, humans are not ingesting the chemical when they put on nail polish, not even by accident, Wong said.

The EU banned TPO because of how their standards are structured, Sass said. The EU took a hazard-based approach to their study, meaning they looked at the intrinsic harm of the chemical or product in isolation. In comparison, the U.S. takes a risk-based approach, taking into account both the risk and exposure.

“That specific part of the FDA, when it comes to banning certain ingredients, is more of a ‘do no harm’ situation, versus ‘here’s a list of every ingredient that you absolutely cannot have in products,’ like what the EU does,” Sass said.

A chemical is banned by the EU as a precaution if it potentially causes cancer, damages DNA and/or adversely affects the reproductive, regardless of whether it has been put through a risk assessment. Because the animal study found reproductive harm, the EU prohibited the use of TPO.

“I think if they did a risk assessment, it wouldn’t have been banned,” Wong said.

Sass suggested that people might see overreactions to the EU’s ban on social media. “The social media thing is, ‘Oh, the U.S. has no regulations. We’re allowing these toxic chemicals in our products.’ And that’s not at all what’s happening in real life.”

Is gel nail polish still safe to use?

When curing the polish, the chemical gets rendered into a “completely different thing that can’t [physically] get through your skin,” chemist Michelle Wong said. Photo via Getty Images

Currently TPO is not banned in the U.S., and it is unclear whether the Food and Drug Administration will follow suit. Since the ban was announced in May, Sass said brands have had time to reformulate their polishes.

Before the ban, TPO was considered safe by the EU at a level of up to 5% in polishes, with “usually at least with a 100-fold margin of safety,” Wong said. This means “you would have to have over 100 times the amount you would have been exposed to” before experiencing negative effects.

When curing the polish, the chemical gets rendered into a “completely different thing that can’t [physically] get through your skin,” Wong said. She estimated that 1% of TPO is left after curing, but added that the nail polish can also continue to absorb natural light.

“If you’ve cured your nails and you are also going into the sun afterwards, [the TPO is] all going to be gone. It’s all going to be reacted away,” Wong said.

For people painting their nails at home, the only real potential risk could be if you paint outside of the nail or if you don’t realize what kind of product you’re using. Even then, Wong said, “that would be very safe.”

“You think your gel polish is normal nail polish, you put it all over your fingers, you don’t cure it. Later on, you realize, oh, it’s still liquid, and then you wash it off. That’s probably, like, the worst-case scenario where you would get exposed to it.”

If you are concerned about TPO, regular nail polish does not have this ingredient and there are TPO-free gel nail polishes.

Despite this, Dr. Rita Linkner, a double-board certified dermatologist, does not recommend gel manicures to her patients because of the potential aging effects on the skin.

The risk is “incredibly low,” Wong said, but there are studies linking UV lights used to cure gel polish to cause mutations in human cells which can increase risk of skin cancer and damage DNA. The Skin Cancer Foundation recommends putting on sunscreen before exposure to the light.

To avoid gel all together, Linkner recommends a regular nail manicure and opting to leave your nails bare every now and then to prevent brittleness.

Hannah Grabenstein contributed reporting.