The UK Ban on TPO in Gel Nail Products: Timeline and Impact

Spectra Cosmetic Compliance

The GB ban is part of SI 2026/23. Regulatory positions can change, so confirm current detail for your products.

What is TPO?

TPO trimethylbenzoyl diphenylphosphine oxide (also written as diphenyl(2,4,6 trimethylbenzoyl)phosphine oxide) is a photoinitiator: a compound that reacts to UV or LED light to start the curing (hardening) of gel nail products. It is what allows a gel polish to change from a liquid to a hard, durable coating in seconds under a nail lamp, with good colour stability.

Because of these properties, TPO became widely used across gel nail systems. In nail products, concentrations typically ranged from around 0.5% to 5%. Its effectiveness made it popular, but its safety classification is what has driven it out of the market.

Why TPO has been banned

TPO (Trimethylbenzoyl Diphenylphosphine Oxide) has been classified as a CMR substance specifically a category 1B reproductive toxicant under CLP chemicals classification law. Under both the EU and UK cosmetics regimes Regulation (EC) No 1223/2009 and the UK Cosmetics Regulation a substance classified as CMR is, as a rule, prohibited in cosmetics unless a specific exemption is granted. In TPO's case, no successful exemption was pursued, so it moves onto Annex II, the prohibited substances list.

It's worth noting, as industry bodies have, that the classification is based on the substance's inherent hazard. When cured under a UV lamp, TPO reacts and is consumed in the hardening process relevant for the gel/UV nail industry specifically. Nonetheless, the regulatory position follows the hazard classification, and the result is a ban on its use in cosmetic products.

The EU timeline

The EU acted first. Under Regulation (EU) 2025/877, TPO was banned in EU cosmetics from 1 September 2025, with no transitional period from that date, both placing on the market and making available TPO containing products were prohibited, including continued supply and professional use in salons. Because Northern Ireland follows EU rules, TPO containing nail products have not been legal there since the same date.

The absence of a transition period made the EU ban abrupt: products had to be off the market and out of professional use immediately. This prompted many nail brands to reformulate to TPO free systems ahead of the date, and to withdraw non compliant stock.

The Great Britain timeline

Great Britain follows through SI 2026/23, which includes TPO among the newly banned CMR substances. For the GB market, products containing TPO cannot be placed on the market from 15 August 2026, and cannot continue to be made available (off-shelf) after 14 February 2027. So GB has a defined placing-on-market deadline with a sell through period into early 2027.

The different dates between the EU (September 2025) and Great Britain (August 2026) reflect their parallel but separate regulatory systems. A brand selling across both markets faced the EU deadline first and the GB deadline later a clear example of the two regimes moving on the same substance but on different timelines.

Who is affected

The ban affects nail product brands, manufacturers, importers and Responsible Persons, and by extension the salons and professionals who use the products. Any gel nail product gel polish, builder gel, and similar UV/LED-cured systems that relies on TPO as its photoinitiator is caught and must be reformulated for the markets concerned.

For salons and nail technicians, the practical step is to check the products they use and buy: the INCI list will show 'Trimethylbenzoyl Diphenylphosphine Oxide' where TPO is present. For brands, the obligation is to remove TPO from formulations sold into the EU and, by the GB deadline, Great Britain.

TPO free reformulation

The industry response has been widespread reformulation to TPO free systems, using alternative photoinitiators that achieve curing without the CMR-classified ingredient. Many brands moved ahead of the EU deadline and are aligning with the GB deadline too, often to avoid maintaining two versions of the same product for different markets.

Reformulating a cured-gel system is a genuine technical exercise the photoinitiator is central to how the product performs so it requires proper development, testing and reassessment, not a simple substitution. Affected products need their CPSR and PIF updated to reflect the new formulation.

What brands need to do

Nail brands should identify every product containing TPO, reformulate to a TPO free system for both the EU (already in force) and Great Britain (by 15 August 2026), manage sell through of existing stock within the deadlines, and update the CPSR and PIF for each reformulated product. Communicating the change to salon and professional customers is also sensible, given their compliance interest.

Because the EU ban is already in effect and the GB deadline is approaching, this is an active, time-sensitive obligation rather than a future one. Brands that have not yet fully transitioned should treat it as a priority. Our guide to SI 2026/23 covers the other substances in the same instrument.

What it means for salons and professional use

An important feature of the TPO ban is that it covers not only retail sale but professional use. Under Regulation (EC) No 1223/2009 and the UK Cosmetics Regulation, a salon using a TPO containing product on clients is "making available" that product in the course of commercial activity so once a ban is in force, professional use is caught too. In the EU, the ban has applied since September 2025, meaning TPO containing UV gel and nail polish products should no longer be in professional use.

For nail technicians and salons in Great Britain, the practical step is to check every product they use and stock against the SI 2026/23 compliance deadline, and to source TPO free systems in good time. The INCI list will show "Trimethylbenzoyl Diphenylphosphine Oxide" where TPO is present, so identifying affected products is straightforward with a little attention to the label.

This professional use dimension is why the TPO ban has had such a visible impact across the nail industry, prompting brand-to-salon communication across the sector. For brands, supporting professional customers through the transition clear information, TPO free alternatives, and updated CPSR and labelling documentation is both good practice and good business, given how closely the two are connected here.

TPO ban at a glance

References: SI 2026/23 (legislation.gov.uk); Regulation (EU) 2025/877 (EUR-Lex); European Commission TPO Q&A; OPSS and CTPA guidance. Verified July 2026; confirm current detail before acting. General information only, not legal advice.