This scientific opinion of the EFSA Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids deals with the safety evaluation of the recycling process ExtruPET (EU register number RECYC0124), which is based on the Starlinger IV+® technology. The input of the process is hot caustic washed and dried poly(ethylene terephthalate) (PET) flakes originating from collected post-consumer PET containers, containing no more than 5 % of PET from non-food consumer applications. In this technology, washed PET flakes are dried and crystallised in a reactor, then extruded into pellets which are further crystallised in a second reactor. Crystallised pellets are then pre-heated in a third reactor and fed to the solid state polycondensation (SSP) reactor. Having examined the challenge test provided, the Panel concluded that the three steps, drying and crystallisation, extrusion and crystallisation and SSP are the critical steps that determine the decontamination efficiency of the process.