Migration of catalyst elements from polyethylene terephthalate bottles into food simulants and mineral water under short- and long-term conditions

As polyethylene terephthalate (PET) bottles are common beverage containers, their safety is a matter of grave concern. In this study, migration behaviour of five elements (Ge, Ti, Sb, Co and P) used as catalysts, bluing agents and stabilizers during manufacturing from PET into beverages were assessed. Migration tests were performed on eight unused PET bottles under various conditions (food simulants: distilled water, 4% acetic acid and 50% ethanol; time: 10 days to 24 months; temperature: 25–60°C). The migration levels of two catalyst elements (Ge and Sb) under these conditions were 0.12–31.9 and <0.1–1.8, respectively, whereas Ti, Co and P were not detected (<2, <0.1 and <20 μg/L, respectively). The results showed storage temperature were positively correlated with migration of Sb and Ge in all food simulants. Different food simulants led to different levels of these elements migration at the same storage time and temperature, and the levels into 50% ethanol were higher than those into the other two food simulants. It was also shown that migration levels of Sb and Ge were below 2 and 20 μg/L even after 2 years of storage at room temperature, not exceeding the Japanese and EU regulation values. The Sb levels in distilled water were similar to those in commercially available bottled mineral waters, indicating that the migration tests provide a good reflection of the actual situation.