TPO is short for trimethylbenzoyl diphenylphosphine oxide. In gel nail polish, it acts like a light starter: under UV or LED light, TPO triggers the reaction that makes the polish hard and glossy. The technical term for this kind of light starter is photoinitiator.
That sounds pretty hard to understand, right?
TPO is like a light switch. UV gel only hardens when it gets light from the lamp, and TPO plays the role of the switch that turns that light on. That is why the gel becomes firm and shiny.
Why did the EU ban TPO?
The EU classified TPO as a Category 1B CMR substance, meaning toxic for reproduction. As a result, TPO had to be included in Annex II of the EU Cosmetics Regulation, which is the list of prohibited substances. The ban applies from September 1, 2025, to the placing on the market, sale, and use in cosmetic products. (more)
Are lamp-free gel nail strips an option?
Yes, if they are fully cured. Such UV-free strips come already cured from the factory and do not require a lamp; they may be formulated without TPO. For partially cured, or semi-cured, strips, a lamp is needed for the final curing step, and photoinitiators may be included. Therefore, the key is to check the INCI list and the manufacturer’s instructions.
Why choose TPO-free products?
They are legally compliant in the EU, help avoid potential risks, especially in cases of repeated occupational exposure, and effective alternatives already exist. For consumers, this means looking for “TPO-free” claims and checking the INCI list.
LAONSI Gel nail,
Because LAONSI nail strips are already fully cured during the production process, no UV lamp is required and there are no harmful effects caused by lamp curing. In addition, they are TPO-free, so you can use them with confidence. (more)