Antimony leaching from polyethylene terephthalate (PET) plastics used for beverage in Japan

To investigate the safety level of softdrink bottled in plastic, the amount of antimony (Sb) existing in polyethylene terephthalate (PET) bottles was examined. The Sb concentrations in beverages and polyester resin itself were measured by graphite furnace atomic absorption spectrophotometer (GFAAS). A detection limit (3σ) of 0.4 μg/L was achieved. PET bottles were classified into five groups based on their uses: (A) pressure-tight bottles for carbonated drinks; (B) bottles for aseptic cold filling mainly used for drinking waters; (C) bottles for aseptic hot filling mainly used for noncarbonated cold drinks; (D) heat-resistant bottles for hot teas; and (E) bottles for alcohol drinks. 70% of PET bottles were categorized into group C. The concentration of Sb observed from PET resin ranged from 6.08 to 216.49 mg/kg, while the range of Sb contaminated in bottled solutions was from 0.26 to 1.55 μg/L. The detected Sb amounts from all drinks were below the guidelines recommended for drinking water of Japanese standard at 2 μg/L, and 90% of bottles solutions contained Sb lower than 1μg/L. The contaminated Sb in drink solutions mainly came from the Sb2O3 used in the manufacturing of PET as a catalyst. The measurement of Sb existing in various parts of the bottle shows no significant difference. However, the storage of the pressure-tight PET bottle at higher temperatures had a significant effect on the time-dependent release of antimony, while the sunlight had no effect on leaching of Sb from PET at ambient temperature. However, the amounts leached following 133 days at storage condition 25, 40, 55, and 70 oC, and with/without sunlight were less than Japanese standard.