How do you know if your products contain TPO?

First of all, it is important to know that you only need to check products that cure under a lamp – such as gels, BIAB, topcoats, and gel polish. Products that do not cure, such as nail polish, care products, or liquids, generally do not contain TPO.

Whether a product contains TPO depends on several factors such as the purchase date, lot number, and the specific batch.
You cannot check this via a general list – you must verify each product individually.

How do you do that?
Take the bottle or jar and look at the ingredients list (INCI) on the label.
Check whether one of the following is listed:

• Trimethylbenzoyl Diphenylphosphine Oxide
• Diphenyl(2,4,6-trimethylbenzoyl) phosphine Oxide
• (2,4,6-trimethylbenzoyl) diphenylphosphine Oxide

Is this ingredient listed on the label? Then the product contains TPO and may not be used or sold within the European Union from 1 September 2025.

Note: Sometimes ingredients are listed under alternative or commercial names that cannot be found in official lists.
If such a name does not have a recognized CAS number, the ingredient does not officially fall under the regulations.
Without a correct CAS number, you cannot be sure whether the product is legally permitted or not.
In that case, it is advisable to be extra cautious and request further information from the supplier.