The EU ban on TPO (trimethylbenzoyl diphenylphosphine oxide, INCI: Trimethylbenzoyl Diphenylphosphine Oxide) in finished cosmetic products took effect on 1 September 2025, capping a regulatory year that Cosmetics & Toiletries' end-of-year recap maps as one of the most binding twelve-month stretches in a decade.

What does the recap cover?

The publication groups the year's activity into five workstreams: the TPO prohibition, microplastics phase-in timelines, siloxane concentration ceilings, the recast Urban Wastewater Treatment Directive and a cluster of UK post-Brexit divergences. The piece is positioned as a compliance planning aid for formulators, regulatory affairs teams and procurement leads operating across both jurisdictions.

Why the TPO date matters

TPO served as the workhorse photoinitiator in UV/LED-cured nail gels and builder systems. Its reclassification as a CMR category 1B substance under the EU's CLP Regulation removed it from the Cosmetics Regulation (EC) 1223/2009 positive list. Reformulation now rests on Type I and Type II alternatives — TPO-L (ethyl phenyl(2,4,6-trimethylbenzoyl)phosphinate), BAPO, 819 and 184 — each requiring toxicological due diligence and supply-chain qualification.

Where do microplastics stand?

Commission Regulation (EU) 2023/2055 restricted intentionally added synthetic polymer microparticles under 5 mm that are not biodegradable. Cosmetics feature prominently in the schedule, with transition periods running into the late 2020s for rinse-off formats and into the early 2030s for leave-on categories. The recap walks readers through which SKUs — exfoliants, microbeaded cleansers, polymer-based glitters — fall inside scope and which exemptions apply to biodegradable polymers.

Which siloxane limits apply?

D4, D5 and D6 sit under REACH Annex XVII entry 70. Wash-off cosmetics face a 0.1% w/w ceiling for D4 and D5; leave-on products carry a D4/D5 limit of the same order, and D6 a separate threshold. The recap's trade angle: silicone-alternative sourcing — plant-derived emollients, ester oils, modified dimethicones — is now a board-level procurement question, not a research curiosity.

What do wastewater rules change?

Directive (EU) 2024/3019, the recast Urban Wastewater Treatment Directive, set a 31 December 2025 transposition deadline for member states. For cosmetics manufacturers, the practical lever is the extended producer responsibility (EPR) regime covering pharmaceutical and personal-care residues — reporting, ecotoxicology data and producer fees start to bite in 2026.

What shifts for UK formulators?

The Office for Product Safety and Standards (OPSS) maintains a parallel but distinct regime. The UK has retained the 0.1% siloxane thresholds, has not yet mirrored the EU's CMR-driven TPO prohibition and is consulting on microplastics under its own REACH-style framework. Dual-market operators now run two regulatory trackers.

What is the forward calendar?

Three dates dominate the next twelve months. The microplastics transition clock continues ticking toward its rinse-off and leave-on milestones. The wastewater EPR fee framework starts producing invoices in 2026. And the EU's working group on cosmetic-ingredient biodegradation testing is expected to publish its first methodology paper before Q3 2026 — a data point R&D and procurement should monitor closely.