Dip nails DO NOT contain the banned ingredient TPO. Only UV light cured materials contain TPO.

What is TPO?

Diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide, commonly known as TPO, is a photoinitiator. Under ultraviolet (UV) light, it releases radicals that can go on to facilitate polymerization reactions.

TPO has a variety of uses, including UV-curable inks, coatings, adhesives, and 3D-printing resins. The reason it’s in the news right now is because it’s a key ingredient in gel nail polish.

What is TPO doing in nail polish?

Gel nail polish relies on a radical polymerization reaction to harden—that’s why you have to stick your hands under a lamp to cure your manicure. TPO is a widely used photoinitiator for kicking off the curing process in gel polish because it doesn’t affect the color of the polish formulation, and it’s effective even in thick layers of polish.

Why is TPO banned in the EU now?

The European Union passed the ban in May 2025 on the basis that TPO is classified as a class 1B reproductive toxin. The ban went into effect on Sept. 1, 2025. Class 1B means that a chemical is presumed to be harmful to the human reproductive system based on animal studies.

TPO is not facing bans or regulations anywhere besides the EU.

Do dip nails contain TPO?

Classic dip powder systems use: Powder + resin (glue) + seal. No UV light needed. That means traditional dip systems usually DO NOT contain TPO—because they don’t rely on light curing.

How to know for sure?

Check the ingredient list for “Trimethylbenzoyl diphenylphosphine oxide”, or look for labels like:

• “TPO-free”
• “Hema-free / 9-free” (not always the same, but often overlap in “clean” formulas)

Pure dip system (no lamp) → you’re likely not dealing with TPO.
Anything involving UV/LED curing → assume it might be there unless proven otherwise.