Migration of phthalates from PET water bottle in events of repeated uses and associated risk assessment

Abstract

Phthalates are widely used as a plasticizer in manufacturing polyethylene terephthalate (PET) bottles to improve softness, flexibility, durability, longevity, and workability. Phthalates are known in instigating profound human health hazards. In many developing countries, lack of proper disposal facilities established for empty PET bottles and the absence of legislation on reuse invariably persuade people to reuse them for storing potable water. An experiment was conducted with two commercial brands of PET bottles to explore the potential of phthalate migration when domestically refilled and reused in multiple times at two temperature conditions. Temperatures of ambient (27 ± 2 °C) and warm (60 ± 2 °C) were selected as the refilling temperatures because of the common practice by people. For both brands, only bis(2-ethylhexyl) phthalate (DEHP) levels were detected in refilled water in every event of reuse. For both brands, mean DEHP levels migrated to water at 60 ± 2 °C were significantly higher (p < 0.05) compared to those at 27 ± 2 °C. Risk analyses carried out on human health suggested that there exist no definite acute or chronic health risks when the refilled water is consumed continuously for 30 years for both temperatures. Still, such risks were higher for the consumption of refilled water of warm temperatures than those of ambient temperature. However, this study elucidates that DEHP migration would be at an alarming rate when the events of reuse of a single bottle increase so that regulations banning the reuse of empty PET bottles are paramount, especially for developing countries.