The mirror–shine gel manicure has a catch. As of September 1–2, 2025, the European Union banned TPO—short for trimethylbenzoyl diphenylphosphine oxide—a photoinitiator that helps gel polish harden under UV/LED lamps. Regulators upgraded TPO to a CMR 1B classification (a substance that may be carcinogenic, mutagenic, or toxic to reproduction), which triggers an automatic cosmetic ban in the EU.

Why the alarm? Much of the concern comes from animal studies. EU scientific opinions note repeated-dose studies in rats showing testicular atrophy and other reproductive effects; developmental studies reported skeletal variations in fetuses at high doses. While these exposure levels don’t mimic a salon manicure, they informed the EU’s precautionary stance.

Dermatologists and chemists point out that real-world nail exposure is far lower than the doses used in those studies, and prior assessments once allowed up to 5% TPO in professional gels. Still, after the CMR upgrade, no exception was granted—so salons across the EU must stop using and discard TPO-containing products.

In the United States, there’s no equivalent ban—so TPO gels remain on the market. Expect ripple effects, though: global brands are already promoting TPO-free systems to simplify worldwide compliance. If you love gels, ask your tech for formulas that skip TPO or choose brands explicitly labeled TPO-free.

What to do now

- Check the ingredient list (INCI) or salon SDS sheets; TPO may appear as “trimethylbenzoyl diphenylphosphine oxide.”

- Consider TPO-free gels or rotate with regular polish breaks to reduce cumulative exposure.

- Mind the lamp: proper curing technique and protective measures (e.g., fingertip-covering UV gloves) can limit other risks associated with gel services.

The EU ban doesn’t prove gels cause infertility in humans—but it does signal enough reproductive-toxicity concern in animals to rethink what’s on your nails. If that high-gloss finish is a must, make it an informed one.