Do you know what TPO is?

Changes in Nail Styling Are Here – What Happens After 1 September 2025?

The nail styling industry is facing important changes! As of 1 September 2025, a ban has come into force across the entire European Union on the use of certain ingredients in nail styling products. What does this mean in practice, and which products will no longer be allowed?

Which ingredients are leaving the market?

The European Union has banned the placing on the market of cosmetics containing two ingredients:

Dimethyltolylamine [CAS 99-97-8] – applies to acrylic products intended for nail styling.
Trimethylbenzoyl Diphenylphosphine Oxide [CAS 75980-60-8] – TPO – applies to light-curing products intended for nail styling.

According to the latest position of the European Commission, the use of cosmetic products as part of business activity (beauty salons, professional nail styling) constitutes “making available on the market”. The ban applies regardless of the date of purchase of the cosmetic product. This means that after 1 September 2025 such products can no longer be used on clients, even if they were purchased earlier.

This position was presented during the Q&A session regarding TPO.

TPO in Nail Products – Questions & Answers (European Commission)

Where can Dimethyltolylamine be found?

Dimethyltolylamine is found in products used for nail styling with the acrylic method, such as:

liquids/monomers used in the traditional two-component acrylic system (acrylic powder + liquid/monomer),
activator-type products used in dip powder (titanium) manicures.

In other words – if your salon uses classic acrylics or dip powder, you are probably working with this ingredient.

What is Dimethyltolylamine?

Sounds complex? Dimethyltolylamine is an organic chemical compound belonging to the group of aromatic amines. It acts as an initiator in the polymerisation process of acrylic systems. It is essential to trigger the polymerisation between acrylic powder components and the monomers in the liquid (or activator – in the case of dip powder manicures).

Simply put – it helps start the hardening process of the acrylic mass. Without it, powder and liquid would not create a durable nail styling.

In which cosmetic products can Trimethylbenzoyl Diphenylphosphine Oxide (TPO) be found?

TPO can be found in light-curing nail styling products, such as:

coloured gel nail polishes, bases, top coats, and gels.

What is Trimethylbenzoyl Diphenylphosphine Oxide (TPO)?

Trimethylbenzoyl Diphenylphosphine Oxide (TPO) is an organic chemical compound. It acts as a photoinitiator in the polymerisation process of light-curing products – those that harden under UV/LED lamps. It is essential to initiate the polymerisation process between product components.

In other words – it is thanks to TPO that gel polishes, gels, and other light-curing products harden and become durable.

What should you do as a nail stylist?

Check if the products in your salon contain Dimethyltolylamine (especially liquids, monomers, and activators).
Check if the products in your salon contain Trimethylbenzoyl Diphenylphosphine Oxide (TPO) (especially light-curing products).
If in doubt, contact the manufacturer – they should clearly indicate whether a given product contains a banned ingredient.