The European Union has introduced new restrictions on a chemical commonly found in gel nail polishes, citing potential reproductive risks. Trimethylbenzoyl diphenylphosphine oxide (TPO), a photoinitiator that helps gel polish harden under UV light, is now prohibited in cosmetic products sold or used within the EU.

European regulators classified TPO as a “reproductive toxicant,” prompting a ban that took effect this week. The restriction applies only to products containing TPO—gel nail polish itself remains legal as long as approved alternatives are used. Any remaining TPO-based products must be withdrawn from the European market.

TPO has long been favored in salon formulas because it speeds up curing time and durability. But research conducted in animals has linked the compound to testicular abnormalities and reduced fertility, prompting concern for frequent users and salon workers. “Exposure to TPO is of greater concern for salon workers and consumers who regularly get professional gel manicures,” says David Andrews, acting chief science officer at the Environmental Working Group.

Cosmetic chemist Kelly Dobos cautions against alarm, emphasizing that most data comes from animal-feeding studies, a very different exposure pathway than topical nail use. “When applied as directed, these products have generally been considered safe,” Dobos explains. “But there are already alternatives available, and some brands have proactively reformulated.”

Industry experts stress that this is not a blanket ban on gel manicures. “Headlines calling this a ‘ban on gel polish’ are misleading,” says Doug Schoon, chair of the Nail Manufacturer Council on Safety. “Consumers and professionals can be reassured: gel polish products remain fully available, provided they use approved ingredients.”

The United Kingdom is expected to follow with similar restrictions next year, while TPO remains permitted in the United States. The FDA has not indicated plans to impose a federal ban, though some analysts predict individual states may adopt their own ingredient restrictions in the future.

For consumers, the shift means asking salons about product labels—or opting for traditional nail polish, which has decades of documented safety.

Image by Jennifer Avello for MOD Magazine, 2016.