Since 1 September 2025, a ban on two substances that were present in some semi-permanent nail polishes and gels has come into force across the European Union: TPO (Diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide) and DMPT (N,N-Dimethyl-p-toluidine).
In this article we want to offer you a clear, reliable guide, based on official sources, to answer the main questions that are coming up around this regulation.
What does European regulation say about TPO and DMPT in nail polish?
The ban is set out in Commission Regulation (EU) 2025/877, published in the Official Journal of the European Union at the end of May.
This regulation amends Regulation (EC) 1223/2009 on cosmetic products, adding these two substances to Annex II (list of prohibited substances).
Literally, Annex II adds:
No. 1667 – Diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide
No. 1668 – N,N-Dimethyl-p-toluidine
The text establishes that, as of 1 September 2025, no cosmetic product in the European Union may be manufactured, marketed or used if it contains these substances.
There is no grace period: products already in stock cannot be sold or used in salons either.
You can consult the full regulation on the official EU database (Eur-Lex):
What are TPO and DMPT in nail products?
Both are photoinitiator substances used in semi-permanent nail polishes and gels to allow the product to harden when exposed to a UV/LED lamp.
TPO (Trimethylbenzoyl Diphenylphosphine Oxide): a widely used photoinitiator prized for its efficiency, fast curing times and good finish.
DMPT (N,N-Dimethyl-p-toluidine): also used as an accelerator in polymerisation processes.
The problem is that European authorities have classified both as CMR substances (carcinogenic, mutagenic or toxic for reproduction), which means they are banned in cosmetic products.
Which nail products contained TPO and DMPT?
These components are usually found in the following nail products:
-
Semi-permanent nail polishes
-
Nail building and sculpting gels.
-
Some top coats and base coats that cure under a lamp.
They are not present in every product on the market, but they were found in a significant share of formulations due to their effectiveness as photoinitiators.
How to identify TPO and DMPT on the ingredient list (INCI)?
On the ingredient list (INCI), they may appear under different names:
TPO: “Trimethylbenzoyl Diphenylphosphine Oxide” or “Diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide”.
DMPT: “N,N-Dimethyl-p-toluidine” or “Dimethyl-p-toluidine”.
If you find any of these names on a product, it can no longer be marketed or used in the European Union as of 1 September 2025.
When was the European regulation on TPO published, and when did it come into force?
Regulation (EU) 2025/877 was published in the Official Journal of the European Union at the end of May 2025.
The regulation set out a period of just over three months for the industry to adapt, with its application scheduled for 1 September 2025.
Manufacturers and distributors have considered this window very short, since reformulating and getting cosmetic approvals usually takes longer. This is why many brands weren't able to have their new formulas ready by the time the regulation came into force.
What has Seena Owell done in response to the TPO and DMPT ban?
At Seena Owell, safety and transparency have always been our priority. That's why, as soon as we learned about the publication of the new regulation, we began reviewing our catalogue and contacted our nail polish manufacturers to make sure they reformulated in compliance with the new rules.
On 1 September 2025, when the regulation came into force, we no longer had any products containing these banned components for sale.
Where can you find official information about the European nail polish regulation?
We know a lot of confusing information has circulated on social media, and some other distributors are even still selling or clearing out these banned products at big discounts. At Seena Owell we believe it's our duty to act and inform accurately.
In addition to the regulation, the European Commission has published a Questions and Answers document on TPO in nail products, which explicitly clarifies that:
“As of 1 September 2025, products containing TPO can no longer be placed on the market or used in the European Union. There is no transition period to sell off existing stock.”
👉 You can read it here: European Commission – TPO nail products Q&A
The new regulation represents a major change for the beauty and manicure sector.
As professionals, it's essential to stay informed in order to offer our clients safe, up-to-date services that comply with current legislation.
At Seena Owell we'll keep supporting you with reformulated products, transparent advice and our commitment to always being a reliable source of information for your business.
If you need to clarify any doubts or want professional advice, don't hesitate to contact our team:
- Via live chat on our website: https://seenaowell.com
- By phone or WhatsApp: (+34) 914 213 059 / (+34) 618 578 678
- By email: info@seenaowell.com
