Health officials have banned a key ingredient used in gel nail polish across Europe over fears it could be toxic to humans—but it will remain on sale in the UK and US. 

The European Union have prohibited the use of trimethylbenzoyl diphenylphosphine oxide—commonly referred to as TPO—in all cosmetic products as of 1 September after studies linked the chemical to long-term fertility issues.

At present, the ban does not affect the UK but industry insiders expect a similar ban to come into play towards the end of 2026. 

TPO is widely used in the cosmetic industry as a photoinitiator, which speeds up the drying time and helps the nail polish harden when exposed to ultraviolet light. 

It is also thought that the chemical helps gel polishes hold their colour for longer, offering a glossy, long-lasting manicure. 

But, while gel polish stays put for weeks, rather than days, due to the UV curing process, experts warn it can actually pose serious health risks. 

Nail salons across the EU's 27 member states, as well as other countries that mirror its regulations such as Norway, have been informed that they must stop offering TPO-based nail gels, and safely dispose of their current stock. 

Manufacturers will also now have to reformulate their products to be TPO-free. 

As yet, the US has not introduced any such regulations, though experts say the ban could affect the American beauty industry if salons source their products from Europe.

Francesca Rapolla, senior affairs manager at the Cosmetic, Toiletry and Perfumery Association said that in some cases industries can submit scientific information to the authorities to prove that the risks posed by the product can be mitigated, meaning that the ingredient would not be banned in cosmetics.

'In the case of TPO, the industry did not and could not defend the continued use of this ingredient in nail products mainly because it could not demonstrate that there are no alternative ingredients to this one,' she told Scratch magazine. 

But other experts have said that the precautionary ban is not supported by robust scientific evidence, and could even pose unnecessary economic burdens. 

Doug Schoon, a scientific consultant at Schoon Scientific, warned in an open letter appealing the ban: 'If left uncorrected, this decision will once again impose unnecessary economic burdens, waste safe products, and undermine confidence in EU regulatory proportionality.'

The Belgian retailer ASAP Nails and Beauty Supply have also publicly opposed the ban stating that it will cause 'major economic damage' to small businesses and that there is 'no human evidence of danger'. 

It comes as experts have blamed cosmetic products used by millions of women for a surge in debilitating gynaecological conditions known to cause fertility issues. 

Studies have linked toxic chemicals known as endocrine disruptors to a host of health issues including diabetes, obesity and some cancers. Now experts say they could be behind the rise of incurable reproductive disorders. 

Cases of endometriosis—a condition where tissues that normally line the womb grow outside of it, causing pain and potentially infertility—have risen from just over 3.4million globally in 1990 to 190million today.

According to experts, the most concerning chemicals are phthalates, also known as plasticisers.

As well as making plastics more flexible and durable, they increase the risk of breast cancer and have been directly linked to causing developmental delays in babies exposed to them in the womb. 

However, when used in cosmetic products, the chemicals can seep through the skin, disrupting the body's natural production of—and response to—natural hormones like oestrogen and testosterone, increasing the risk of breast cancer and fertility issues.  

Professor Katie Burns, an expert in toxic chemicals and fertility at the Burns Laboratory at the University of Cincinnati College of Medicine previously told the Daily Mail: 'These are chemicals that will stay in the body for a long, long time, hidden in fatty tissue. 

'They impact the immune system, and in some women we believe this may trigger reproductive problems and endometriosis.'