TPO

Definição
TPO (Trimethylbenzoyl Diphenylphosphine Oxide) is a photoinitiator used in some UV and LED-cured nail products, including gel polish, builder gels, and other light-cured coatings. Photoinitiators absorb energy from curing lamps and initiate polymerisation, allowing liquid gel products to harden into a durable coating on the nail.

Function in Nail Products
In nail coatings, TPO helps ensure efficient curing, contributing to product hardness, colour stability, and overall performance. It enables gel systems to cure evenly under UV or LED exposure, forming a solid polymer structure required for long-lasting nail enhancements.

Regulatory Status
TPO has been reclassified under cosmetic safety legislation, resulting in its planned removal from cosmetic products within the European Union and Great Britain. Under UK Cosmetics Regulation updates, products containing TPO will no longer be permitted to be newly placed on the market from August 2026, followed by a transition period allowing existing stock already supplied to remain available for a limited time.

For further guidance on timelines and what this means for nail professionals, see our article on the TPO Ban.

Industry Impact
The restriction applies to the ingredient rather than gel nail systems themselves. Manufacturers are reformulating products using alternative photoinitiators that achieve comparable curing performance while meeting updated regulatory requirements.

Professional Considerations
Nail professionals are encouraged to remain informed about ingredient changes and confirm compliance updates with their product suppliers. As with all light-cured nail products, correct application techniques and avoidance of skin contact remain important for safe professional use.