On September 1, 2025, the European Union banned two ingredients that had been in the majority of gel nail products for decades. The headlines that followed were dramatic and not always accurate, and plenty of US techs are still fielding questions from clients who read them.
So here is the plain version: what was banned, why, what the evidence actually supports, and what a nail tech in North Carolina or anywhere else in the US should take from it.
Two Ingredients, Two Very Different Reasons
The ban covered HEMA and TPO. They do completely different jobs in a gel formula, and they were restricted for completely different reasons. Lumping them together is where most of the confusion comes from.
HEMA: The Bonding Monomer
HEMA (2-hydroxyethyl methacrylate) is a small monomer that helps gel adhere to the nail plate. Its small size lets it penetrate skin before curing, and repeated contact with uncured product can cause the immune system to become sensitized. That sensitization is permanent. Once it happens, the person reacts to every future exposure, and often to related acrylates used in dentistry and medicine.
Dermatology literature has flagged HEMA as one of the fastest-growing occupational allergens among nail technicians, with onset most often reported after two to five years of regular professional exposure. Techs who have never had a problem may simply still be inside that window.
TPO: The Photoinitiator
TPO (trimethylbenzoyl diphenylphosphine oxide) is a photoinitiator. It is the ingredient that absorbs lamp light and kicks off the curing reaction. It is also a contributor to the heat spike some clients feel under the lamp.
The EU classified TPO as a CMR category 1B substance, meaning presumed to be carcinogenic, mutagenic, or toxic to reproduction. That classification came from animal studies in which the animals were fed large repeated doses. EU cosmetic law automatically bans CMR 1B substances regardless of whether real-world exposure would produce the same risk. That is a hazard-based approach: if a substance can cause harm under any conditions, restrict it.
What the Science Supports
It is worth being honest that the evidence is not equally strong for both ingredients.
On TPO, the exposure scenario in the animal studies (ingesting large doses) is nothing like trace skin contact during a manicure. At the concentrations used in gel, generally between 0.5% and 5%, and with a proper cure, most cosmetic chemists consider real-world reproductive risk to be very low. Once cured, TPO is bound into the polymer and cannot be absorbed. The EU ban reflects a regulatory philosophy, not a finding that TPO harms people in normal use.
On HEMA, the picture is much less contested. It is a documented occupational allergen with a well-understood mechanism. Techs face far more exposure than clients because of how many applications they perform. There is no reversal once sensitized. That risk is real regardless of what any regulator decides.
What Is Actually Banned, and Where
In the EU, the ban was immediate. Salons could not use existing stock after September 1, 2025, even product they had already paid for. Many had to dispose of inventory and rebuild service menus with no transition period.
The United Kingdom followed with a phased approach: no new TPO products on the market from August 15, 2026, and all remaining stock out of professional use by February 14, 2027. HEMA in the UK is restricted to professional use, with a broader review still in progress.
In the United States, neither ingredient is banned. The FDA regulates cosmetics on a risk-based model, which weighs actual exposure rather than hazard alone, and most industry observers consider a federal ban unlikely in the near term. State-level action, most plausibly in California, remains possible but was not scheduled as of this writing.
In July 2025, the European Commission also published a draft reform that would require regulators to assess real-world exposure before restricting an ingredient. If adopted, it would move Europe closer to the FDA’s approach. The existing ban is not expected to be reversed, but the direction of travel is notable.
Side by Side
| HEMA | TPO | |
|---|---|---|
| Role in the formula | Adhesion monomer | Photoinitiator (starts the cure) |
| Type of risk | Permanent allergic sensitization | Reproductive toxicity in high-dose animal studies |
| Strength of evidence | Well established in nail techs | Contested at real-world exposure levels |
| EU status | Banned Sept 1, 2025 | Banned Sept 1, 2025 |
| UK status | Professional use only | New sales banned Aug 15, 2026; full removal Feb 14, 2027 |
| US status | Not banned | Not banned |
| Syren Cosmetics gel | HEMA-free | TPO-free |
Why It Still Matters in the US
No US ban does not mean no US consequences. Three things are already happening.
Clients are asking. The EU ban was covered by national outlets well outside the beauty trade press. US consumers read those stories and now search for HEMA-free and TPO-free salons. Being able to say clearly what you use, and why, is a competitive advantage.
Major brands have already reformulated. Because the EU rule applies to any product sold there, global manufacturers had to choose between running two product lines or reformulating once for every market. Most reformulated globally. The products on US shelves are changing whether US law does or not.
The occupational risk does not check regulatory status. A client who gets gel every three weeks has one exposure profile. A tech doing eight sets a day, five days a week, has a very different one. If you work behind the table, moving to HEMA-free product is one of the most direct things you can do to protect your ability to keep working.
Where Syren Cosmetics Stands
Syren Cosmetics develops its gel and acrylic formulas in-house in Wilmington, North Carolina. Because we control the formula, we can tell you exactly what is in it, and what is not: Syren Cosmetics gel is HEMA-free and TPO-free. Whatever the regulatory picture looks like in the US next year, our approach is the same: full ingredient transparency, and formulas built for the people who use them all day.
Written by the Syren Cosmetics team. Regulatory details are accurate to the best of our knowledge as of September 2026 and may change; this article is not legal advice.