In a study published on August 31, 2016 in a peer-reviewed journal Food and Chemical Toxicology, Birgit Mertens and colleagues from the Scientific Institute of Public Health, Belgium evaluated the potential health risks of select chemicals migrating from polycarbonate (PC) replacement baby bottles.
In several earlier studies, substances migrating from PC alternative baby bottles bought in Belgium were detected, identified and quantified. That research showed that not all of the substances found to migrate from PC replacement bottles are included in the positive list (Annex I) of European regulation for plastic food contact materials (EU No 10/2011). Those not included were represented not only by the non-intentionally added substances (NIAS) migrating from plastics, such as reaction and degradation products, but also by substances migrating from non-plastic FCMs, such as silicones. Genotoxic potential of 48 of these substances was investigated using in silico and in vitro test methods (FPF reported), and the endocrine activity of 65 substances was tested in a panel of in vitro assays (FPF reported)
In the present study, health risks associated with select quantified migrants were investigated for 24 baby bottles, of which 17 were made of polypropylene (PP), two of polyamide (PA), two of polyethersulfone (PES), and one of each of silicone, Tritan™, and stainless steel. Health risks were evaluated for 17 substances that showed quantifiable migration in the third migration solution of at least one bottle. For this, the following strategy was adopted: (i) all substances were checked for being listed as (suspected) endocrine disruptors, (ii) for substances included in the Annex I of Regulation 10/2011, their migration values were compared with the corresponding specific migration limits (SML), if available, and (iii) for substances not included in the Annex I of Regulation 10/2011, a literature search for toxicological information obtained in other contexts was performed, followed by an evaluation according to the threshold of toxicological concern (TTC) approach.
After comparing to endocrine disruptor lists, three bottles were identified to be of “high concern”, urgently requiring further investigation of associated risks. This was due to the detection of two recognized endocrine disruptor chemicals, dibutyl phthalate (CAS 84-74-2) shown to migrate from one silicone and one PP bottle, and 4-tert-octylphenol (CAS 140-66-9) shown to migrate from another PP bottle. Two more migrants turned out to be ‘suspected’ endocrine disruptor chemicals, hence their source bottles were identified to be of “concern”. These included benzophenone (CAS 119-61-9) migrating from the silicone bottle and three PP bottles, and diisobutyl phthalate (CAS 84-69-5) migrating from the silicone bottle.
For the 4 migrants listed in the Annex I of Regulation 10/2011, azacyclotridecan-2-one (CAS 947-04-6), benzophenone, dibutyl phthalate, and 2, 2,4-trimethyl-1,3-pentanediol diisobutyrate (TXIB; CAS 6846-50-0), their migration in the third migration solution was below the respective SMLs, making adverse health effects unlikely.
For the 13 migrants not listed in the Annex I of Regulation 10/2011, first a literature search was performed to collect any toxicity data available. Data could be found for acetophenone (CAS 98-86-2), diisobutyl phthalate, and 2-butoxyethyl acetate (112-07-2). The latter chemical was evaluated by read-across from 2-butoxyethanol (CAS 111-76-2). For all three chemicals, their migration from baby bottles at the levels measured was considered to be of no concern (in this assessment, the potential endocrine disruptor effects were not taken into account).
For the remaining 10 substances, the TTC approach proposed by the European Food Safety Authority (EFSA) was applied, using several different exposure scenarios. Based on this assessment, two bottles were considered to be of “high concern”. In these bottles, one made of silicone and another one of PP, the TTC values were exceeded by the migration levels of 3,5-di-tert-butylbenzoquinone (CAS 719-22-2) and 4-phenylbenzophenone (CAS 212-93-0), respectively; the toxicological data available were deemed insufficient to guarantee the absence of adverse health effects at migration levels detected. Fifteen more bottles were considered of “concern” because the migration levels of some migrants exceeded the TTC values, and, although some data are available suggesting the absence of potential health effects, these required additional independent evaluation.
Combining the endocrine disruptor- and the TTC-based evaluations, 4 bottles were considered to be of “high concern” (the single evaluated silicone bottle and three PP bottles), and 14 bottles were considered to be of “concern” (the single evaluated Tritan™ bottle and 13 PP bottles). The remaining 6 bottles were considered to be of “no concern” based on the risk assessment conducted (both PA and both PES bottles, the single evaluated stainless steel bottle, and one PP bottle).
Importantly, the authors note, the TTC approach was applied on the individual substances and not on mixtures. To evaluate the mixture effects of substances migrating from PC replacement baby bottles, further methodological refinements would be necessary.
Mertens, B., et al. (2016). “Evaluation of the potential health risks of substances migrating from polycarbonate replacement baby bottles.” Food and Chemical Toxicology (published August 31, 2016).
Mertens, B., et al. (2016). “Investigation of the genotoxicity of substances migrating from polycarbonate replacement baby bottles to identify chemicals of high concern.” Food and Chemical Toxicology 89: 126-137.
Simon, C., et al. (2016). “Screening of endocrine activity of compounds migrating from plastic baby bottles using a multi-receptor panel of in vitro bioassays.” Toxicology In Vitro (published September 12, 2016).
Onghena, M., et al. (2016). “Evaluation of the migration of chemicals from baby bottles under standardized and duration testing conditions.” Food Additives & Contaminants: Part A 33: 893-904.
Onghena, M., et al. (2015). “Identification of substances migrating from plastic baby bottles using a combination of low-resolution and high-resolution mass spectrometric analysers coupled to gas and liquid chromatography.” Journal of Mass Spectrometry 50: 1234-1244.
Onghena, M., et al. (2014). “Development and application of a non-targeted extraction method for the analysis of migrating compounds from plastic baby bottles by GC-MS.” Food Additives & Contaminants: Part A 31: 2090-2102.