In a research article published online on August 9, 2021, in the peer-reviewed journal Chemosphere, Rojin Banaderakhshan and co-authors from the University of Natural Resources and Life Sciences Vienna and the Environment Agency Austria, reported on the content of bisphenol A (BPA, CAS 80-05-7) and 13 alternatives to BPA in thermal paper cash receipts and their migration from reusable plastic bottles.
For their experiments, the scientists collected nine cash receipts and five BPA-free labeled plastic drinking bottles with the recycling code 7 from supermarkets and service providers in Austria in the year 2020. Thus, sampling took place after the EU-wide ban on BPA in thermal paper in January 2020 (FPF reported). The researchers extracted the thermal papers with methanol by sonication for 30 min at room temperature. The migration experiments of bottles were performed with water and artificial saliva at 20 °C and migration in water was partly followed by another incubation at 60 °C or 100 °C. Subsequently, all leachates were analyzed for BPA and 13 analogs including bisphenols B, C, F, M, P, S, Z, AF, FL, C12, and 4,4’ as well as p,p-oxybisphenols and tetramethyl-BPA using high-resolution mass spectrometry (UHPLC-MS/MS). The 13 analogs are used as an alternative to BPA and are also bisphenols.
Of the nine thermal paper samples, in eight only traces of the analyzed bisphenols were detected. However, in nearly all samples concentrations of BPS were higher than those of BPA and reached up to 38 µg/g. Whereas BPA and BPS were observed in the majority of samples, BP4,4, and BPB were only found in one thermal paper. Moreover, one receipt contained “extremely high BPA levels, comparative to levels before the restrictions.” Here, the BPA concentration was 11,000 µg/g and exceeded the legal limit for thermal paper in the EU of 0.02% per weight. For the plastic drinking bottles, all migrates contained BPA (up to 0.0047 µg/L) although labeled BPA-free. Besides BPA, low concentrations of BPS (up to 0.0043 µg/L) and traces of BPF (< limit of detection) were detected. No effect of temperature on migration was reported and no concrete difference between migration in saliva or water was emphasized.
Washing of new plastic food contact materials can significantly reduce the release of BPA during use but the washing method has an influence. This was demonstrated by a study published in March 2021 by Rebecca Holmes and co-authors from the College of Medicine at the University of Cincinnati, OH, US in the journal Chemosphere. The scientists acquired ten brand-new Tritan drinking bottles from local and online retailers. Tritan bottles are usually considered BPA-free. In a 24 h migration period, two out of the ten bottles released BPA concentrations of 0.45 µg/L on average into the water which is comparable to concentrations previously reported for polycarbonate bottles.
Based on a survey with 114 individuals, the authors identified the four most common ways consumers clean new plastic drinking bottles before the first use being (1) no washing (8% of respondents), (2) rinsing with water (24%), (3) washing with water and soap (43%) and (4) washing with a dishwasher (25%). Holmes and colleagues applied these methods to the two identified BPA-releasing bottles and found that only dishwashing could significantly reduce BPA leaching from the tested bottles after two washing cycles. Concentrations of leaching BPA fell below the detection limit only after six washing cycles. Handwashing was ineffective for removing BPA from the new Tritan bottles.
Toxicity of the overall migrate was also studied by “using both a vertebrate and an invertebrate model and acute and seven-day exposure paradigms.” Holmes et al. found that the BPA released from the new “Tritan bottles was bioactive, and thus had the potential of eliciting the endocrine-disrupting toxicities.”
BPA is an endocrine-disrupting chemical (EDC) that has been associated with several adverse effects, e.g., on reproduction, and human diseases already at low doses (FPF reported here, here, and here). Due to health effects and legal restrictions, BPA is increasingly replaced by other bisphenols as those studied by Banaderakhshan et al. However, these alternatives are not necessarily of less health concern (FPF reported here, here, and here). Of the 13 BPA analogs analyzed by Banaderakhshan and co-authors, eight are listed in the Food Packaging Forum’s food contact chemicals database (FCCdb) as substances of potential concern. BPS (CAS 80-09-1), BPF (CAS 620-92-8), BPB (CAS 77-40-7), BPC (CAS 79-97-0), BPZ (CAS 843-55-0), BPAF (CAS 1478-61-1), and BP 4,4 (CAS 92-88-6) are included since being potential or putative EDCs, BPC, BPZ, and BPAF are additionally predicted to be hazardous for environmental health and p,p-oxobisphenol (CAS 1965-09-9) for human health.
References
Banaderakhshan, R., et al. (2021). „Bisphenol A and its alternatives in Austrian thermal paper receipts, and the migration from reusable plastic drinking bottles into water and artificial saliva using UHPLC-MS/MS.” DOI: 10.1016/j.chemosphere.2021.131842
Holmes, R., et al. (2021). “Effect of common consumer washing methods on bisphenol A release in tritan drinking bottles.” Chemosphere. DOI: 10.1016/j.chemosphere.2021.130355
