The morning sessions of the fifth Food Packaging Forum (FPF) Workshop addressed the scientific challenges in the risk assessment of food contact materials (FCMs) and focused particularly on toxicological assessments and migration testing. The FPF Workshop took place on October 5, 2017, in Zurich, Switzerland.
Martin Scheringer, Professor of Environmental Chemistry at the Masaryk University, Czech Republic, gave an overview of the scientific challenges in the risk assessment of FCMs by referring to a recent, peer-reviewed publication by the Scientific Advisory Board of the FPF. During this introduction, Scheringer provided regulatory background information and the definitions of safety under the EU and U.S. regulatory frameworks for FCMs. He pointed out main challenges that make risk assessment of FCMs difficult, including (i) the assessment of non-intentionally added substances (NIAS), (ii) the current focus on starting substances, individual chemicals as well as certain toxicological endpoints, and (iii) the inconsistencies between the FCM legislation with other chemical regulations. According to Scheringer, possible solutions could be the use of fewer chemicals and the ban of substances of very high concern (SVHCs) in FCMs. Toxicological tests using the overall migrate and the further development of bioassays that have relevance to human health could also improve risk assessment of FCMs (talk Scheringer).
Eddo Hoekstra, Scientific Officer at the EU Joint Research Centre, Italy, presented detailed and practical insights into the requirements for migration testing in the EU. He explained migration test approaches for those FCMs that have a harmonized regulation. Furthermore, Hoekstra focused on the importance of the surface-to-volume ratio when using migration results for the estimation of exposures. Tests by National Reference Laboratories illustrated that temperature control is essential during migration testing (talk Hoekstra).
Melissa Van Bossuyt, PhD student at the Scientific Institute of Public Health and the Vrije Universiteit Brussel, Belgium, introduced a prioritization strategy for the toxicological assessment of printed paper and board (FPF reported). The reasons to develop such a strategy included the widespread and frequent use of printed paper and board FCMs, the lack of a harmonized European regulation for these materials, the high number of substances without sufficient safety data, and the frequent incidence of food contaminations. The mutagenic potential was chosen as prioritization criterion and, after compiling a database of 6,073 printing ink and paperboard compounds, four in silico prediction models were selected. Depending on the model, 13.5 to 21% of the single substances were mutagenic, whereas 106 out of 1,723 single substances were mutagenic in all models. Finally, Van Bossuyt gave an overview of ongoing work on the in vitro testing of substances that do not have any literature data on toxicity (talk Van Bossuyt).
Jean-Pierre Cravedi, Director of Research at the French National Institute for Agronomical Research (INRA), Toulouse, France, summarized the main results of an international research project on mineral oil saturated hydrocarbons (MOSH) that was published by the European Food Safety Authority (EFSA) in 2017. After introducing the definitions, sources, typical compositions, and toxicological targets of MOSH, Cravedi showed that accumulation of MOSH mainly occurred in the liver and to a lesser extent in adipose tissue of rats and that different MOSH fractions accumulated in these tissues. MOSH exposure affected the relative and absolute liver weight and some MOSH mixtures induced liver granulomas, but MOSH exposure did not affect the immune function of the test animals. Cravedi concluded that the current classification of MOSH into molecules with carbon chain lengths below and above 25 was not supported by their results (talk Cravedi).
Benoît Schilter, Head of Food Safety Research Department at Nestlé, Switzerland, discussed the applicability of bioassays for the evaluation of packaging safety. Although further work regarding the quality, validation, limitations, and data interpretation of bioassays in the context of packaging safety is generally demanded, Schilter presented examples of their successful application. Bioassays were used by Nestlé to test novel coatings that shall fulfill the safety by design concept and a good correlation between the analytical and biological profiles was observed. The use of bioassays to identify chemicals of concern in a migrate could support the application of the threshold of toxicological concern (TTC) concept in the assessment of NIAS. However, a breakthrough is still needed to increase the sensitivity of bioassays and to make them suitable for this application. The use of bioassays after separating the migrates by high performance thin layer chromatography could be a way forward, because this method may allow the direct identification of a bioactive substance by mass spectrometry (talk Schilter).
Muncke, J. et al. (2017). “Scientific challenges in the risk assessment of food contact materials.” Environmental Health Perspectives (published online September 11, 2017).
Van Bossuyt, M., et al. (2017). “(Q)SAR tools for priority setting: a case study with printed paper and board food contact material substances.” Food and Chemical Toxicology (published February 2, 2017).
Cravedi, J.P., et al (2017). “Bioaccumulation and toxicity of mineral oil hydrocarbons in rats – specificity of different subclasses of a broad mixture relevant for human dietary exposures.” EFSA Supporting Publications 14(2):EN-1090 (published online February 22, 2017).