Gel Nail Polish Tied to Cancer Banned in Europe, Still Legal in US

The EU’s prohibition of TPO-containing gels extends to all cosmetic products imported from outside the union.

Published: 9/3/2025, 9:44:35 AM EDT

Gel Nail Polish Tied to Cancer Banned in Europe, Still Legal in US — Nail polishes on display during Sally Hansen Halloween Party at 632 On Hudson in New York City on Oct. 10, 2024. (Ilya S. Savenok/Getty Images for Sally Hansen)

The European Union has banned trimethylbenzoyl diphenylphosphine oxide (TPO), a gel nail polish ingredient classified as potentially cancer-causing and harmful to reproduction.

The European Commission classified TPO as a Category 1B reproductive toxicant under EU chemical law, citing animal studies indicating possible risks of cancer, genetic mutations, and reproductive harm.

That classification led to its mandatory inclusion on the EU’s list of prohibited cosmetic ingredients. “From 1 September 2025, both placing and making available on the market of cosmetic products containing TPO are prohibited,” the Commission stated, noting that the ban applies even to existing stock, which must be removed from sale.

TPO acts as a photoinitiator, allowing gel polish to cure quickly and evenly under UV or LED light, producing the glossy, long-lasting finish that makes gel manicures popular. ProNails, a European nail product supplier, describes it as a highly efficient molecule that triggers a chain reaction, turning liquid gel into a solid three-dimensional structure.

ProNails explains that during the curing process, TPO does not remain intact and no longer exists in its original form. After curing, it is either incorporated into the hardened gel or converted into harmless by-products.

"In either case, it remains locked up in the cured gel: it cannot evaporate, move or come into contact with the skin - it is like being sealed in a vault," ProNails stated. "Even if a tiny residue were not used up, it is mainly in the adhesive layer, where the unreacted molecules are, and in an amount of less than 0.1%."

The chemical is also used outside the nail industry in UV-cured coatings, adhesives, dental composites, and packaging inks.

Many nail brands, including Manucurist, Aprés Nails, and OPI, are now offering TPO-free formulations, and salons across the EU are switching to these alternatives to comply with the new rule.

In the United States, TPO is currently not regulated or classified by federal authorities. TPO remains legal in cosmetics in the United States. The FDA has not issued restrictions on the ingredient, and it continues to be used in UV-cured gel polishes.

According to the EU Cosmetics Regulation, EU member states are required to impose "effective, proportionate and dissuasive" penalties for infringements of the Cosmetics Regulation, including the marketing of non-compliant products. Penalties can include fines, confiscation of products, and other administrative sanctions.

The EU’s prohibition of TPO-containing gels extends to all cosmetic products imported from outside the union.