A common ingredient found in many gel nail polishes has been banned in most of Europe – but it is still freely available in the US, EuroNews reports.

Trimethylbenzoyl diphenylphosphine oxide (TPO) is now officially banned in all cosmetic products after EU regulators deemed it potentially toxic to human health.

TPO is a "photoinitiator" – a chemical that allows the polish to harden under UV light and retain its color brightness for longer.

The ban was introduced after animal studies linked TPO to long-term fertility problems. The EU took a precautionary measure while research continues. Nail salons in the 27 EU member states, as well as in countries such as Norway and Switzerland that follow European regulations, must now stop selling products containing TPO and withdraw existing stocks. Manufacturers are rushing to reformulate their products without the controversial ingredient.

Meanwhile, the US still does not regulate TPO – adding it to a long list of substances and additives, including the preservatives BHA and BHT and the so-called dough conditioner, which are banned in Europe but remain permitted across the Atlantic.

The EU ban could lead to changes. American brands that source products from Europe or develop formulations there may be forced to adapt. This could lead to shortages or even prompt American regulators to take notice.

Some industry representatives oppose the measure. Belgian wholesaler ASAP Nails and Beauty Supply has created a protest website claiming that "there is no evidence of danger to humans" and that the ban will cause "serious economic damage" to small businesses. | BGNES