In the battle against plastic pollution, many efforts are being undertaken to reduce, reuse and recycle plastics. If tackled in the right way, these efforts have the potential to contribute to reducing plastic waste and plastic’s spread in the environment. However, reusing and recycling plastics can also lead to unintended negative impacts because hazardous chemicals, like endocrine disrupters and carcinogens, can be released during reuse and accumulate during recycling. In this way, plastic reuse and recycling become vectors for spreading chemicals of concern. This is especially concerning when plastics are reused for food packaging, or when food packaging is made with recycled plastics. Therefore, it is of utmost importance that care is taken to avoid hazardous chemicals in plastic food contact materials (FCMs) and to ensure that plastic packaging that is reused or made with recycled content is safe for human health and the environment. The data presented in this review are obtained from the Database on Migrating and Extractable Food Contact Chemicals (FCCmigex), which is based on over 800 scientific publications on plastic FCMs. We provide systematic evidence for migrating and extractable food contact chemicals (FCCs) in plastic polymers that are typically reused, such as polyamide (PA), melamine resin, polycarbonate and polypropylene, or that contain recycled content, such as polyethylene terephthalate (PET). A total of 1332 entries in the FCCmigex database refer to the detection of 509 FCCs in repeat-use FCMs made of plastic, and 853 FCCs are found in recycled PET, of which 57.6% have been detected only once. Here, we compile information on the origin, function and hazards of FCCs that have been frequently detected, such as melamine, 2,4-di-tert-butylphenol, 2,6-di-tert-butylbenzoquinone, caprolactam and PA oligomers and highlight key knowledge gaps that are relevant for the assessment of chemical safety.