THE INFLUENCE OF PET CONTAINERS ON ANTIMONY CONCENTRATION IN BOTTLED DRINKING WATER

Antimony trioxide (Sb(2)O(3)) is the most frequently used catalyst in the polyethylene terephthalate (PET) manufacture. As a result, antimony is incorporated into PET bottles at concentration level of 100-300 mg/kg. PET containers are used for drinking water and beverages, as well as food packaging and in the pharmaceutical industry. Thus, it is important to understand the factors that may influence the release of antimony from the catalysts into water and other products, since antimony is potentially toxic trace element. In this paper, the antimony content in nine brands of bottled mineral and spring water from Serbia, and seven brands of bottled mineral and spring water from EU countries was analyzed. The measurements were conducted using the inductively coupled plasma-mass spectrometry (ICP-MS) technique. In the all examined samples the antimony concentration was bellow the maximum contaminant level of 5 mu g/L prescribed by the Serbian and EU regulations. Comparison of the content of antimony in PET bottled waters with the content of antimony in water bottled commercially in glass and the natural content of antimony in pristine groundwaters, provides explicit evidence of antimony leaching from PET containers. Since waters bottled in PET have much greater concentration ratio of Sb to Pb than corresponding pristine groundwaters, it can be assumed that bottled waters cannot be used as the relavant source for the study of the natural antimony content in groundwaters. There is a clear relation between the quality of water in bottles (composition, ion strength) and antimony leaching rate. Moreover, while the rate of antimony leaching is slow at temperatures below 60 degrees C, at the temperature range of 60-80 degrees C antimony release occurs and rapidly reaches maximum contaminant level. As antimony can cause both acute and chronic health problems, factors that promote the increase of antimony concentration should be avoided.