FORMULA FOCUS

TPO Tales

The EU’s ban of an ingredient commonly used in gel nail products is the talk of the industry: so why has it been put into effect & how will this impact your services? HELENA BIGGS explores the facts

On 1 September 2025, trimethylbenzoyl diphenylphosphine oxide (TPO), an ingredient commonly used in nail gel formulas, was banned for use in products made and placed within the EU cosmetics market. The chemical is a photoinitiator that helps gel products cure quickly under UV light and maintain colour stability, and while a ban hasn’t yet been applied within the UK market, it is possible that one may be enforced in 2026.

The move has been controversial owing to its testing phase, and it feels like another attack on gel nail services and the safety of our industry. Some consumer outlets have caused confusion with sensationalist headlines exclaiming ‘gel polish is banned’, which has sent clients into turmoil: concerned about whether they can still enjoy their fortnightly gel-based treatments.

A website has been set up to challenge the EU’s TPO ban. To support the protest, visit www.tpo-eu.com

Why has the ban been introduced?

The European Commission, which has a duty to ensure that cosmetics and personal care products sold in the EU are safe for use, made the decision to ban TPO, and companies (as well as national and European regulatory authorities) have a responsibility to adhere to its rules. Its discussions on TPO started at working group level in March 2024, and when tested, the ingredient was classified as a ‘carcinogen, mutagen, reprotoxic (CMR) category 1B reproductive toxicant’. This triggered the inclusion of TPO in the prohibited substances list of the EU’s Cosmetics Regulation.

This inclusion was discussed with EU member states prior to the adoption – and 25 of 27 agreed with it. The European Commission notes that ‘nobody submitted a derogation request for TPO before the adoption of Regulation (EU) 2025/877’, which is the formal name for the ban.

Francesca Rapolla

Francesca Rapolla, scientific affairs manager at The Cosmetic, Toiletry & Perfumery Association (CTPA), comments: “An industry can voluntarily defend continued use of cosmetic ingredients that receive a harmonised classification as a CMR, by submitting thorough safety dossiers that meet the specific exemption criteria of Article 15 of the EU Cosmetics Regulation.

“In the case of TPO, the nail industry did not, and could not, defend the continued use of the ingredient in products, mainly because it could not demonstrate that there are no alternative ingredients. Therefore, TPO is prohibited for use in cosmetics used within the EU.”

Testing times

It is how the European Commission has come to this decision that is infuriating members of the nail industry. TPO was tested on animals that ingested the ingredient orally in high concentrations: conditions far removed from its involvement within nail services. TPO is found in concentrations of up to 5% in nail products, and is, of course, not ingested by clients or pros.

Doug Schoon

Esteemed nail industry scientist, Doug Schoon of Schoon Scientific, wrote an open letter to the European Commission about the prohibition of TPO in cosmetic products, which addresses the testing phase. An extract reads:

“[The reclassification of TPO] was driven by animal studies, particularly in rats, in which repeated oral administration at high doses produced adverse male reproductive outcomes including testicular atrophy, reduced sperm counts and impaired fertility. It is important to stress that:

• These finding arise exclusively from oral toxicity studies in laboratory animals.

• No human studies have been conducted on reproductive toxicity of TPO.

• The exposure conditions in these animal studies bear no resemblance to realistic exposure scenarios in cosmetic use, where TPO is present at ~1-3% in cured UV gel systems and where oral ingestion is neither intended nor foreseeable.”

Doug suggests that the prohibition is hazard-based, and ‘disregards actual exposure conditions, route of exposure and the finished product safety profile’. The European Commission has acknowledged that the current framework ‘offers little flexibility for economic operators – especially SMEs’, and a proposal to revise the Cosmetics Regulation has been tabled. However, until it is formally endorsed by the European Parliament and the Council, the Commission must apply the law as it currently stands.

“Resources are wasted, as safe products are destroyed not due to genuine safety concerns – but due to regulatory inflexibility. The regulation, as applied, is disproportionate to the actual risk.”

The consequences

As nail technicians use cosmetic products to provide paid services, those in the EU are strictly prohibited from using products containing TPO on clients. “This constitutes ‘making available on the market’ in the course of a commercial activity, and applies regardless of whether the product was purchased before the cut-off date,” states the European Commission.

“This represents financial losses for small businesses and professionals, who have lawfully invested in stock,” Doug Schoon comments. “[It has also created] market disruption for manufacturers, many of whom will be required to undertake costly dossier submissions to demonstrate negligible risk.”

Doug also highlights that resources are wasted, as ‘safe products are destroyed not due to genuine safety concerns – but due to regulatory inflexibility’. He adds: “The regulation, as applied, is disproportionate to the actual risk.”

The rules as they stand

The European Commission shares that companies and professionals in affected member states should have discontinued sale, supply and professional use of TPO-containing products from 1 September. Remaining stock should have been withdrawn from professional premises, and compliant alternatives sought from suppliers.

Countries have different standards for chemical regulation, which can lead to confusion internationally, where there may be different rules for the same ingredient. The US market hasn’t found cause to address TPO use yet, so gel products containing the chemical will likely continue to be available in the US. As for the UK, there are murmurs about a ban coming into effect in late 2026.

Numerous nail brands have responded to the EU ban by launching products with TPO-free formulas or modified forms of TPO. To prevent manufacture of two versions of the same product, we may witness an increase in these alternative formulas. As always, education is imperative. Reassure your clients that TPO is not ingested or likely to enter their bloodstreams in harmful quantities, and when cured, TPO solidifies and deactivates – so there’s no need for them to panic about their gel mani/pedi appointments.