On July 14, 2017 a new scientific study entitled “In vitro toxicity testing of food contact materials: State-of-the-art and future challenges” was published in the peer-reviewed journal Comprehensive Reviews in Food Science and Food Safety. The authors Ksenia Groh and Jane Muncke from the Food Packaging Forum (FPF), Zurich, Switzerland, reviewed the scientific literature describing the use of alternative bioassays for testing the toxicity of food contact materials (FCMs) and food contact articles (FCAs), and discussed future research needs and challenges for broader implementation of this promising approach to ensuring safety of FCMs and FCAs.
Toxicological testing of FCMs is currently focused on single substances and usually only a few toxicological endpoints, most prominently genotoxicity. However, people are commonly exposed to mixtures of substances migrating from FCMs/FCAs into food, which may potentially induce a variety of toxic effects. Moreover, finished FCAs usually contain non-intentionally added substances (NIAS), which present a unique challenge to risk assessment, since in many cases these substances are not available as a pure chemical to carry out the necessary testing, or their chemical identity may even be unknown (FPF reported).
Nonetheless, regulation requires that all substances, including NIAS, that may migrate from FCMs/FCAs into food, should undergo risk assessment. One option to improve the toxicological testing of FCMs/FCAs would be to test their overall migrates or extracts, as this would allow understanding the joint effects of all chemicals present in a mixture. Rapid and cost-effective non-animal-based bioassays would be an ideal tool for such testing, since these assays usually present a rapid and more cost-effective alternative to traditional animal-based toxicological testing.
As the review summarizes, non-animal tests that have been applied for FCMs/FCAs assessment so far included most often various in vitro bioassays, performed with use of cell cultures derived from organs of human or other mammals. Plant cells and unicellular organisms such as bacteria and yeast have also been used, along with tests employing small multicellular organisms such as crustacean larvae or zebrafish embryos. Three main endpoints assessed most often included cytotoxicity, genotoxicity, and endocrine disruption potential, the latter mainly focused on estrogenic and androgenic effects.
As the review authors concluded, a non-animal bioassay-based approach to testing FCMs/FCAs safety is in principle feasible. However, a few remaining challenges should be solved before it can be applied more broadly. The first challenge concerns the procedure for obtaining representative samples, which should be optimized, standardized, and harmonized. Two approaches to sample preparation, extraction-based and migration-based, are available, and the former approach appears to be the most pragmatic.
Another area requiring attention concerns the choice of in vitro bioassays to perform the testing. These assays should have sufficient sensitivity and specificity, and they should also have a clear human health relevance. The significant body of research on chemical exposures’ contribution to the etiology of non-communicable diseases of public concern should be taken into consideration when choosing the most appropriate assays for FCMs/FCAs testing, and agreeing on their interpretation.
Reference
Groh, K., and Muncke, J. (2017). “In vitro toxicity testing of food contact materials : State-of-the-art and future challenges.” Comprehensive Reviews in Food Science and Food Safety (published July 14, 2017).
