Chemical migration in drinking water stored in polyethylene terephthalate ( PET ) bottles : a

Due to its chemical inertness and physical properties PET is particularly suitable for food packaging applications, especially for drinking water. More bottled water is consumed than other bottled beverages. This article is a survey and toxicological investigation of chemical compounds, which are able to diffuse from PET bottles to water. The exact detailed chemical composition of plastic materials is known only from information provided by manufacturers. A declaration of conformity according to EC regulation no.10/2011 is required to ensure the safety of plastic materials in contact with foodstuffs. This regulation established a positive list of monomers and additives which are authorized for use in plastic materials. Some substances are subject to restrictions and/or specifications according to their toxicological data. However, Non-Intentionally Added Substances (NIAS) not listed in this regulation such as breakdown products from monomers and additives and/or impurities found in initial polymerization reactants may be present in a PET bottle wall. Also, recycled PET can be a source of unknown chemical compounds found in water. All these substances may potentially migrate from the PET bottle wall to bottled water. It is well-known that acetaldehyde and antimony are leached from PET bottles. However, several studies have shown the presence of other substances not expected a priori in bottled water, sometimes in non-negligible concentrations. The origin of these compounds has not been clearly established and remains controversial (PET container, cap sealing resins, background contamination, water processing steps, NIAS, etc). Overall, it is difficult to compare the reported results due to the variety of parameters favoring the release of substances (contact time, type of simulant, temperature, sunlight exposure and bottle color). Considering all these difficulties and controversies, further investigations are needed to clearly identify the migration products from PET and to ensure that the consumption of PET-bottled water does not involve any health hazards.