Evaluation of the potential migration risks of baby bottles used as substitutes for polycarbonate

Introduction: Bisphenol A (BPA) has been used as a starting product in the manufacturing of food contact materials for many years until the European Commission prohibited further use of BPA in the production of polycarbonate (PC) baby bottles based on the precautionary principle. Consequently, PC has been replaced by many other materials such as polypropylene, polyamide, polyethersulfone, silicone and glass. Although many studies have been conducted to evaluate the release of substances from PC baby bottles, such data are currently lacking for PC replacement products.

Materials and methods: In this study, the potential migration risks associated with the alternative materials were investigated by using an integrated approach combining analytical and toxicological tools. First, a market study was conducted to identify the available alternative materials. Next, representative samples were selected and migration experiments were performed according to EU Regulation 10/2011, followed by chemical identification of the migrants. In parallel, the biological activity (genotoxicity and endocrine activity) of the identified migrants was evaluated using literature data and a battery of in silico and in vitro assays. Afterwards, the exposure of the infants to the migrants was estimated. Finally, a preliminary risk assessment of the identified substances was performed.

Results: For the risk assessment, a distinction was made between migrants listed in Annex I of Regulation 10/2011 and the unlisted substances (e.g. Non Intentionally Added Substances (NIAS)). For the listed substances, concentrations in the migration solutions were compared to their respective specific migration limits (SML) (when applicable). Migration of all substances was shown to be below their SML. For the unlisted substances, the Threshold of Toxicological Concern (TTC) approach was applied. The estimated exposure of some unlisted substances exceeded the human exposure threshold determined by the TTC-concept. For these substances, a more in-depth risk assessment was performed based on the collected toxicological information.

Conclusion: The current study shows that the combination of chemical and toxicological information allows to perform a preliminary risk assessment of substances migrating from PC replacement products. However, the safety evaluation of baby bottles is challenging, in particular for the NIAS.