RESUMEN
Since 1930s, production of synthetic plastics from non-renewable resources (mainly from petroleum) has been growing with applications in different fields. The use of plastics in packaging began after World War II. Polyethylene films introduced transparent and resealable bags, being the bread bags the first application of contact with food. Nowadays, packaging is the largest single market for plastics (about a quarter of the total production) with a high proportion used for direct contact with foods (1). Polymers and low molecular weight additives compose the plastics, where the latter are necessary to maintain the plastic properties (2). During the late-1970s and early-1980s there was a number of publications reporting that small molecules diffused through the polymer chains in the plastic and moved to the contained food by means of a process called migration (3, 4). This kind of interaction between plastic packaging and food opened a new research field, and many materials were analysed for migration. Also, the identity and quantification of the diffusion rate of the migrants were reported, and legislation was established in order to protect the health of consumers who were not aware about the plastic components contaminating their food (5). The beginning of the 21 Century brought new analytical technologies that helped to quantify migration levels that were not able to be detected with the 20 Century technologies. The researchers working in that field concluded at some point that the interaction between plastic and food exist in all the cases, and could be limited but not completely avoided.