Update on the status of trimethylolpropane (TMP)
1,1,1 Trimethylolpropane (TMP)*, also known as propylidynetrimethanol, is widely used as a surface coating on titanium dioxide (TiO₂). It enhances flow and dispersion properties in many applications including paints, coatings, adhesives and inks.
In 2022, the Finnish authorities notified the European Chemicals Agency (ECHA) of their intention to propose a harmonised classification for TMP as toxic for reproduction category 1B under the EU Classification and Labelling Regulations (CLP). After several delays, ECHA announced on 4 March 2026 that the Finnish authorities had withdrawn the intention due to resource constraints.
As a result, TMP remains self-classified as a category 2 suspected human reproductive toxicant. Notwithstanding the dossier withdrawal, further regulatory developments or scrutiny at EU or Member State level cannot be excluded. Customers seeking grade specific information should refer directly to their TiO₂ supplier.
The TDMA are continuing to closely monitor the situation, including investigating a review of the available scientific information to assess the potential implications and to better understand any next steps that may be considered by authorities.
*EC number 201-074-9 and CAS number 77-99-6
