Beginning September 1, the European Union has officially banned a chemical widely used in gel nail polishes, citing potential health risks.
The substance, known as TPO (trimethylbenzoyl diphenylphosphine oxide), is responsible for the glossy, long-lasting finish that makes gels so popular, but studies suggest it may carry serious dangers.
What is TPO and why is it banned?TPO acts as a photoinitiator, helping gel polish harden quickly under UV or LED lamps while creating the sleek, chip-resistant finish customers love.
However, European regulators determined the chemical poses risks to fertility and reproductive health. It has now been classified as “carcinogenic, mutagenic or toxic to reproduction” under EU law, and according to a 2024 study.
Although not every gel polish contains TPO, many brands still rely on it. Until recently, the ingredient was only permitted for professional use at a maximum concentration of 5%. Now, its sale and use in cosmetics are prohibited outright, with no grace period for salons to sell through old stock.
The EU’s move follows its history of banning ingredients considered unsafe abroad; such as BHA, BHT, and certain additives still permitted in U.S. food and beauty products.
Ban is precautionary, experts saySome specialists believe the prohibition is a protective step rather than a direct response to human cases. “The European Union is banning it out of caution,” explained dermatologist Dr. Hannah Kopelman, per WellnessPulse. “Even though we don’t yet have large-scale human studies proving harm, the potential risks were enough to warrant stricter regulation.”
TPO is also used in dental materials, though the EU’s decision applies only to cosmetics, not medical products.
The ruling has left nail salons and product importers scrambling. Many argue that the September 1 deadline arrived too quickly, giving them little time to source TPO-free alternatives. With no exceptions allowed, salons are now required to discard existing stock immediately.
Meanwhile, the United States has not placed restrictions on TPO. American consumers may still encounter the ingredient in many gel nail brands, with no mandatory labeling requirements to highlight its presence.
For those concerned about exposure, experts recommend asking salons for TPO-free products, spacing out gel manicures, applying protective base coats, and ensuring treatments are done in well-ventilated environments.
But TPO isn’t the only health concern tied to gel manicures. The UV or LED lamps used to cure polish may increase skin cancer risk, according to podiatrists, while over-prepping the nail plate can cause long-term damage.
Allowing gels to “grow out” also carries risks, including infection from Pseudomonas bacteria (often called “greenies”) which causes the nail to turn green or blue when moisture seeps beneath lifted polish. While usually harmless in healthy people, the bacteria can cause severe infections in those with weakened immune systems.