Pollutants delivered every day: Phthalates in plastic express packaging bags and their leaching potential.

The rapid development of the express industry brings not only convenience but also environmental problems such as plastic wastes. In this study, we collected plastic express packaging bags from major express companies in China to investigate phthalates in them. Infrared spectra indicated that all these samples were made from polyethylene but with different carbonyl index (CI) values. Total phthalates (∑Phthalates) concentrations in these samples ranged from 11.16 to 309.70 μg g-1. Di(2-ethylhexyl) phthalate, di-n-butyl phthalate, and di-isobutyl phthalate were predominant phthalates. The leaching amounts of ∑Phthalates after 48 h ranged from 181.44 to 5320.64 ng g-1. The leaching amounts of ∑Phthalates significantly positively related to ∑Phthalates concentrations of samples, while the leaching ratios presented opposite trends. Concentrations and leaching amounts of ∑Phthalates and major phthalates were significantly higher in samples from high CI value company group than those from low CI value company group. The results of our study indicate that plastic express packaging bags could be a critical source of phthalates. The involving of recycled plastics during the manufacture of plastic express packaging bags may influence the content and composition of phthalates in them and also increase the releasing risk of phthalates.