Review of the existing maximum residue levels for fenbutatin oxide according to Article 12 of Regulation (EC) No 396/2005

According to Article 12 of Regulation (EC) No 396/2005, EFSA has reviewed the maximum residue levels (MRLs) currently established at European level for the pesticide active substance fenbutatin oxide. Although this active substance is no longer authorised within the EU due to the lack of toxicological data on di‐hydroxy fenbutatin oxide, a compound observed in the metabolism studies but also present as an impurity in the technical active substance, MRLs established by the Codex Alimentarius Commission (CXLs) are still in place. Lacking a full toxicological characterisation of this compound, it was not possible for EFSA to perform an assessment of these CXLs and their incorporation in European legislation cannot be recommended. Nevertheless, available data allowed EFSA to propose a marker residue and a limit of quantification (LOQ) for enforcement against potential illegal uses.