•Prioritisation for testing 24 substances of the 1 478 in the EU Pesticide Database.•A five-step workflow based on European regulations and reports is proposed.•Detailed physicochemical properties for the selected substances are reported.•Future needs for thermal degradation studies are discussed. This study aims at estimating which pesticide active substances (ASs) are the best candidates to study potential further degradation of the AS above 120°C. To achieve this, a prioritisation list was built following five consecutive criteria. This first includes substances that are anthropogenic, have a carbon backbone structure, are authorized in the European Union, and have a defined maximum residue limit (MRL). Then, substances were selected according to their physicochemical and structural properties, MRL in main food commodities, standard price and degradation in hydrolysis studies below 120°C. The results showed that out of the initial 1 478 substances reported in the European pesticide database, 24 ASs were selected as the best candidates to test the assumption of degradation above 120°C. This prioritisation list could be useful for future research studies to build their own list and save time in selecting suitable candidates according to their criteria.