Safety Verification for Reuse of PET and Glass Bottles

In order to verify the safety associated with reusing PET and glass bottles, a challenge test was conducted with five surrogate contaminants: 1,1,1-trichloroethane, chlorobenzene, toluene, benzophenone and phenyl cyclohexane. Bottles were filled with a cocktail solution of these contaminants and stored at 50 °C for 7 days, then washed with water and alkaline solutions. Material and migration tests were conducted at each step. The material test results showed that 430-1,440 µg/g of the contaminants were retained after water washing, and that even after washing with a 3.5% NaOH solution, 225-925 µg/g of the contaminants were retained. The migration tests revealed that 0.095-7.35 µg/mL of the contaminants were eluted. Similar tests were conducted with a soft drink ingredient, limonene. The results revealed that 48 µg/g of limonene was retained even after washing with NaOH solution, and that 0.16 µg/mL of limonene was eluted. Conversely, no contaminants were eluted from glass bottles after washing with the NaOH solution. Thus, from the viewpoint of safety and the preservation of content quality, PET bottles are not considered suitable for reuse when compared with glass bottles.