TPO in gel nail polishes: why the EU and UK have banned it

For years, it remained hidden within an INCI name that no one pronounces. Then, within twelve months, TPO became the most discussed abbreviation in salons: banned in cosmetics in the European Union from 1 September 2025, and banned in new products placed on the market in Great Britain from 15 August 2026.

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The news gave rise to two opposing narratives. In the first, every gel manicure would suddenly be toxic. In the second, the ban would be mere bureaucracy and would mean nothing. Neither interpretation accurately reflects what happened.

The issue is that three different things have become mixed together: an ingredient, a product category, and a legal classification. They need to be distinguished; otherwise, people end up fearing the lamp and blindly trusting a badge.

Why gel has taken over manicures

Gel manicures meet a very concrete desire: glossy colour, an even surface, and longer-lasting wear than traditional nail polish. The difference lies in how the formula transforms.

A classic nail polish dries mainly through solvent evaporation. A gel, on the other hand, contains a system of monomers and oligomers that, when exposed to light from a compatible UV or LED lamp, polymerizes and forms a solid network. Photoinitiators are needed to start the reaction: molecules capable of absorbing light energy and triggering curing.

TPO (listed as Trimethylbenzoyl Diphenylphosphine Oxide, CAS number 75980-60-8) is one of these photoinitiators. It was valued because it enables efficient polymerization and performs well even with the most opaque colours, where light struggles to reach deeper layers. However, it is not the only available system: many formulas were already TPO-free, and others have been reformulated with different photoinitiators.

The distinction is essential. The authorities did not ban gel manicures, lamps, or all photoinitiators. They banned one specific substance in cosmetic formulations.

How the ban came about

The story did not begin with a viral post, nor in 2025. It is the result of a sequence of events spanning several years.

From the old safety opinion to the new classification

In 2015, the European Scientific Committee on Consumer Safety, the SCCS, assessed TPO and concluded that, under the conditions examined at the time, it could be considered safe at concentrations of up to 5% in certain professional UV nail gels. That opinion is often cited as if it contradicted the current ban.

In reality, it addressed a different question, using the data and classification available at the time. In subsequent years, new assessments of reproductive toxicity emerged. In September 2021, the Committee for Risk Assessment of the European Chemicals Agency adopted an opinion supporting a more severe classification, later formalized by Delegated Regulation (EU) 2024/197.

TPO thus entered the Repr. 1B category: a substance presumed to be toxic to human reproduction based on the body of evidence required by the European system. The harmonized indication is H360Fd, “may damage fertility; suspected of damaging the unborn child.”

Precision is needed here, because online the acronym CMR (carcinogenic, mutagenic or toxic to reproduction) has conflated very different categories. TPO was not banned because it was classified as carcinogenic. It was banned because of the third letter of the acronym.

Why a classification has automatic consequences

The European Cosmetics Regulation generally prohibits substances classified as CMR category 1A or 1B, unless an exemption is obtained by meeting very strict conditions and is accompanied by a favorable SCCS assessment for the specific use. It is the same mechanism I described regarding the new CMR rules that reached the pharmacy counter.

No derogation request with an updated dossier was submitted for TPO. Regulation (EU) 2025/877 therefore added it to Annex II, the list of substances prohibited in cosmetics. As of September 1, 2025, in the European Union, it is no longer permitted to place on the market or make available cosmetic products containing it.

The Commission also clarified a point that had caused confusion in salons: in the EU, there is no period for using up old stocks. After that date, a professional may not use a product containing TPO on a client, even if it was lawfully purchased before the ban.

What changes in Great Britain from 15 August 2026

Outside the European Union, the dates do not coincide. In Great Britain (England, Scotland and Wales), Statutory Instrument 2026 No. 23, adopted in January 2026, added TPO and fifteen other CMR substances to the list of substances prohibited in cosmetics. The ban on placing new products on the market took effect on 15 August 2026.

However, there is a transition that the EU had not granted. Products already legally placed on the British market before that date may continue to be made available until 14 February 2027: after that, distributors and retailers may no longer sell them, and professionals may no longer repurchase them.

There is a further difference, and it is the one that matters most in everyday practice. According to the interpretation of the British cosmetics industry association, agreed with trade enforcement authorities, professionals in Great Britain may continue to use stocks already purchased even after February 2027, until they run out. This was never possible in the EU. Same substance, two transition philosophies.

Northern Ireland is a special case: under the product rules applicable within the framework of the Windsor Framework, it follows the European Union’s cosmetics regime and therefore the European ban from 1 September 2025.

For people who travel or shop online, this geography matters. The same product may have a different status depending on the market and the date on which it entered the supply chain. “It is still for sale” does not mean the rule is false: it may indicate a legal transition, a different market or, naturally, a non-compliant offering.

Hazard and risk: the distinction that avoids slogans

The TPO classification describes a hazard: the inherent capacity of a substance to produce a harmful effect under the conditions considered in toxicological tests. The risk to a person also depends on the dose, route and duration of exposure, frequency, and the way the product is used.

This distinction is not intended to minimise the ban. It is intended to explain why two statements can both be wrong: “if it is banned, one manicure makes you infertile” and “if it has not been demonstrated in clients, then there is no problem at all.” The first turns a regulatory classification into an individual diagnosis. The second ignores the principle by which cosmetics legislation manages substances classified as having serious effects.

The basis for the classification concerns toxicological and reproductive data, not a study that measured infertility after occasional manicures. Neither the European nor the British decision demonstrates that a single application caused fertility damage in people. At the same time, when a substance enters such a severe legal category, the law requires specific justification for keeping it in cosmetics, and no one submitted such a request for TPO.

The ban, therefore, is not a retroactive medical bulletin for people who have used gel in the past. It is a risk-management decision based on a new classification.

“The most interesting test is not the size of the ‘free from’ label. It is the quality with which a formula has been redesigned, tested, and explained.”

“TPO-free” is useful, but it does not tell the whole story

The new claim addresses a real need: it enables salons and customers to identify formulas that comply with the rule. If truthful, “TPO-free” is simple and useful composition information.

The problem arises when we assign it meanings it does not have. A TPO-free product is not automatically:

• free from all photoinitiators;
• free from HEMA or other (meth)acrylates;
• hypoallergenic;
• not requiring proper curing;
• gentler for everyone;
• usable with any lamp.

Reformulation does not consist of removing one word from the INCI. Changing the photoinitiator system can affect curing speed and depth, colour stability, compatibility with the lamp, and the amount of unreacted material. It is the finished formula, under its conditions of use, that needs to be assessed, not the absence of one line.

For this reason, it makes little sense to improvise combinations of gels and lamps just because a product displays a new claim. The exposure time and wavelength specified by the formulator are part of the system, exactly like the product itself.

The separate issue of acrylate allergies

Something doesn't add up in the way gel safety is discussed: while TPO is at the centre of a decision on reproductive toxicity, much of what is actually seen concerns something else, namely sensitisation to (meth)acrylates. This happens especially when uncured product touches the skin or when the lamp does not cure it completely.

HEMA and Di-HEMA Trimethylhexyl Dicarbamate are not synonyms for TPO. In the EU, they are permitted in nail products only for professional use and must carry specific warnings. An analysis published in 2024 of 394 nail cosmetics available for purchase online detected HEMA in 58% of the products, Di-HEMA in 34%, and at least one of the two in 67%. This is a snapshot of that sample and market, not a universal estimate; it nevertheless shows how easy it is to conflate different chemical issues under a single “safe gel” label.

Allergic contact dermatitis can cause itching, swelling, redness, blisters, cracking, or nail separation. Sometimes symptoms also appear on the eyelids, face, or neck due to transfer by hand. The British Association of Dermatologists points to a particular risk with home kits, when the gel comes into contact with the skin or curing is insufficient.

Avoiding skin contact with uncured product, following the instructions, and using a compatible lamp therefore remain valid precautions even in a TPO-free world. If a reaction is suspected, continuing to try different formulas on your own only complicates the picture: it is safer to stop and seek a medical or dermatological evaluation.

How to check a gel without becoming chemists

For those who do not work with formulas, the check can remain simple. Four steps, in order of usefulness.

1. Look for the exact INCI name

The name to look for is Trimethylbenzoyl Diphenylphosphine Oxide. “TPO” is the technical abbreviation, but the label normally lists the full INCI name.

2. Ask the salon which formula is being used

A reliable answer does not require absolute promises. It is enough for the professional to be able to identify the product, the market it is intended for, its ingredient list, and the lamp it is designed for. In the EU, after September 1, 2025, the presence of old stock does not make its use on a client legitimate.

3. Do not use the claim as a universal shortcut

TPO-free answers the question “does it contain TPO?” Allergies, lamp compatibility, and correct application require different questions. “HEMA-free” also does not mean “free of all acrylates” and does not guarantee that sensitization will not occur.

4. Protect your skin and nails with practical steps

Do not peel off the gel with your fingers, do not leave liquid product on the skin, and take breaks when your nails are fragile. For skin exposure during lamp use, the American Academy of Dermatology suggests applying broad-spectrum, water-resistant sunscreen with SPF 30 or higher to your hands, or wearing opaque dark gloves without fingertips.

How I see it

I observe with curiosity how the market turns a technical change into an immediately recognizable claim. It's useful when it helps people choose a compliant product. It becomes less useful when a single absence is presented as synonymous with total safety.

There's also a lesson that goes beyond nails and concerns cosmetics as a whole. A favorable safety opinion from 2015 was superseded by a 2024 classification. Not because science had lied, but because the data, questions, and regulatory thresholds had changed. It's the same misconception I described when discussing the fear of chemicals reaching sunscreens: a revision is presented as a confession, when it's maintenance.

And there's one point that concerns me personally, because it's the reason we chose pharmacies and parapharmacies as our distribution channel. Faced with news like this, the right question isn't “what should I avoid?” but “who can I ask?” Pharmacies and parapharmacies that distribute LeLang receive notifications about formula changes before the product reaches the shelf, and the person behind the counter has the training to read an INCI instead of repeating a claim. It's a conversation no large-print label can replace.

One less acronym, more of the right questions

The ban on TPO doesn't bring the era of gel manicures to an end. It accelerates a reformulation process already underway and brings the United Kingdom and European Union toward a substantially aligned framework, with different timelines.

The most useful lesson isn't to fear every lamp or trust every “free-from” label. It's about distinguishing the ingredient's name from the product category, hazard classification from individual risk, regulatory compliance from tolerability, and TPO from acrylate allergies.

You can't judge a manicure by a single acronym. But an acronym can become the starting point for asking for traceable formulas, compatible tools, and more precise information.