Polyethylene terephthalate (PET) is a polymer deemed safe to be mechanically recycled and used in food contact applications. Its recycled form (rPET) can be used as a food contact material (FCM). Although this is an obvious positive step towards a more circular economy, the development of an appropriate analytical toolbox to experimentally assess and evaluate the various steps during end of life and mechanical recycling is still at its infancy. The safety of the decontamination process is currently evaluated following a conventional modelling approach applied to a specific number of compounds (challenge test). However, additional compounds, quality markers and process controls are needed, with respect to migrating substances, potential non-intentionally added substances (NIAS), contaminants and known polymeric degrading compounds. This would ensure an additional level of safety and provide recomendations for the application of appropriate methods when ensuring full compliance with safety standards for rPET. This review presents the current regulatory framework and the most recent developments in analytical methodologies related to compliance testing. It also highlights some of most described chemical substances found in food-grade rPET.