Semi-permanent varnishes: a substance considered toxic prohibited for use

TPO (diphenyl trimethylbenzoyl phosphine oxide) is used in particular in cosmetic products for nails. This substance allows semi-permanent varnish to harden and dry quickly, once placed under a UV or LED lamp, and therefore not to remain in the liquid state on nails.

TPO is now classified as a “CMR substance” (carcinogenic, mutagenic or toxic to reproduction), as it may affect fertility or embryonic development. This classification, based on scientific studies, is harmonized at EU level.

Since 1^er In September 2025, in all European Union countries, professionals in the cosmetics sector are therefore no longer authorized to use products containing TPO as part of their services (varnish application, manicure, etc.). No time limit for disposal of stocks shall be granted ; professionals cannot use products containing TPO that were already in their possession.

It is also now forbidden:

• make cosmetic products containing TPO available to anyone (including professionals);
• to market this type of cosmetic products.

These various prohibitions stem from Regulation (EU) 2025/877 of 12 May 2025, which takes into account the latest scientific data and amends Regulation (EC) No 1223/2009 on cosmetic products. The TPO is now deleted from Annex III to Regulation (EC), which allowed the use of this substance in a professional setting only in artificial nail preparations, at a maximum concentration of 5 %; the substance is now included in Annex II (prohibited substances).