The toxicological testing of food contact materials (FCMs) has been dominated by a focus on single substances typically tested for only a few toxicological endpoints, most prominently genotoxicity. In contrast, people are commonly exposed to mixtures of substances migrating from FCMs into food, and upon chronic exposure to these chemical mixtures, a variety of toxic effects other than genotoxicity could potentially be induced. To improve the relevance of adopted testing procedures for assessing the impacts of real-life exposures on chronic toxicity outcomes, the toxicological testing of FCMs could be adjusted to testing their overall migrates or extracts through rapid and cost-effective non-animal-based bioassays. These bioassays should be selected on the basis of their relevance for the endpoints and outcomes of interest, for example, with regard to non-communicable diseases of current public health concern that are suspected to be potentially induced or affected by chronic chemical exposures. In 2017, the Food Packaging Forum published an article in the peer-reviewed journal Comprehensive Reviews in Food Science and Food Safety on the state-of-the-art and future challenges of in vitro toxicity testing of FCMs. A summary article is available, and the full article can be downloaded for free from the publisher’s website.
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 16(5): 1123-1150.
Currently, toxicological testing of food contact materials (FCMs) is focused on single substances and their genotoxicity. However, people are exposed to mixtures of chemicals migrating from food contact articles (FCAs) into food, and toxic effects other than genotoxic damage may also be relevant. Since FCMs can be made of more than 8 thousand substances, assessing them one-by-one is very resource-consuming. Moreover, finished FCAs usually contain non-intentionally added substances (NIAS). NIAS toxicity can only be tested if a substance’s chemical identity is known and if it is available as a pure chemical. Often, this is not the case. Nonetheless, regulations require safety assessments for all substances migrating from FCAs, including NIAS, hence new approaches to meet this legal obligation are needed. Testing the overall migrate or extract from an FCM/FCA is an option. Ideally, such an assessment would be performed by means of in vitro bioassays, as they are rapid and cost-effective. Here, we review the studies using in vitro bioassays to test toxicity of FCMs/FCAs. Three main categories of in vitro assays that have been applied include assays for cytotoxicity, genotoxicity, and endocrine disruption potential. In addition, we reviewed studies with small multicellular animal-based bioassays. Our overview shows that in vitro testing of FCMs is in principle feasible. We discuss future research needs and FCM-specific challenges. Sample preparation procedures need to be optimized and standardized. Further, the array of in vitro tests should be expanded to include those of highest relevance for the most prevalent human diseases of concern.