Assessing the effect of sunlight exposure and reuse of polyethylene terephthalate bottles on phthalate migration

Nowadays, polyethylene terephthalate (PET) bottles are widely used for packaging drinks and food. However, concerns have been raised about the possible migration of harmful chemicals, particularly phthalates, from these containers into their contents. Therefore, this study investigates the effects of sunlight exposure and PET bottle reuse on phthalate migration, focusing on three common phthalates: bis(2-ethylhexyl) phthalate (DEHP), dibutyl phthalate (DBP), and benzyl butyl phthalate (BBP). The study used two experimental designs. First, new PET bottles filled with distilled water were stored in the shade and under direct sunlight for 30 days. Second, PET bottles were reused to store various foods (vinegar, mint extract, salty leaves, pickled cucumber, and lemon juice) at 4 °C and 40 °C for 10, 30, 60, and 90 days. Phthalate concentrations were analyzed using solid phase extraction followed by gas chromatography–mass spectrometry (GC/MS). The results showed that exposure of PET bottles to sunlight significantly increased phthalate migration compared to shaded storage (P < 0.001). When reused, storing PET bottles at 40 °C resulted in significantly higher phthalate release from the bottle walls in all storage periods than at 4 °C (P < 0.001)—at 40 °C, longer storage times resulted in a significant increase in phthalate migration (P < 0.001), while at 4 °C storage time had no significant effect on phthalate levels (P < 0.001). This study shows that sunlight, higher storage temperatures, and longer storage times significantly increase the migration of phthalates from PET bottles into their contents. These results highlight the importance of maintaining appropriate storage conditions and limiting the reuse of PET bottles, particularly at higher temperatures and longer storage times, to minimize potential exposure to phthalates. © 2025 Elsevier B.V.