Migration of antimony from PET bottles into beverages: Determination of the activation energy of diffusion and migration modelling compared to literature data

Frank Welle (1) , Roland Franz (1)

1 Fraunhofer IVV - Fraunhofer Institute for Process Engineering and Packaging

Plastics bottles made from polyethylene terephthalate (PET) are increasingly used for softdrinks, mineral water, juices and beer. In this study a literature review is presented concerning antimony levels found both in PET materials as well as in foods and food simulants. On the other hand, 67 PET samples from the European bottle market were investigated for their residual antimony concentrations. A mean value of 224 ±32 ppm was found, the median was 220 ppm. Diffusion coefficients for antimony in PET bottle materials were experimentally determined at different temperature between 105 °C and 150 °C. From these data the activation energy of diffusion for antimony species from the PET bottle wall into beverages and food simulants was calculated. The obtained value 189 kJ mol-1 was found to be in good agreement with published data on PET microwave trays (184 kJ mol-1). Based on these results the migration of antimony into beverages was predicted by mathematical migration modelling for different surface/volume ratios and antimony bottle wall concentrations. The results were compared to literature data as well as international legal limits and guidelines values for drinking water as well as migration limit set from food packaging legislation. It was concluded that antimony levels in beverages due to migration from PET bottles manufactured according to state-of-the-art can never reach nor exceed the European specific migration limit of 40 ppb. Maximum migration levels caused by room temperature storage even after 3 years will never be essentially higher than 2.5 ppb and will be in any case below the European limit of 5 ppb for drinking water. The results of our study confirm that the exposure of the consumer by antimony migration from PET bottles into beverages and even into edible oils reaches approximately 1% of the current TDI established by WHO. Having substantiated such low antimony levels in PET bottled beverages the often addressed question on estrogenic effects caused by antimony from PET bottles appears to be groundless.

Mots clés: Life Sciences

Frank Welle, Roland Franz. Migration of antimony from PET bottles into beverages: Determination of the activation energy of diffusion and migration modelling compared to literature data. Food Additives and Contaminants, 2010, 28 (1), pp.115. ⟨10.1080/19440049.2010.530296⟩. ⟨hal-00654489⟩