Hazardous chemicals in non-polar extracts from paper and cardboard food packaging: an effect-based evaluation

Background Food contact articles are used in our everyday life and information regarding the potential health hazards of migrating chemicals for humans is scarce. In this study, an effect-based evaluation of non-polar extracts of food contact articles made of paper and board was conducted with a panel of eight bioassay endpoints. These, health-relevant endpoints, included oxidative stress, inflammation, genotoxicity, xenobiotic metabolism and hormone receptor effects. Results In total, 62 food contact articles were pooled into 19 groups, in which articles intended to be used for similar types of food item(s) were pooled, and extracted with acetone:n-hexane (1:4). These were then tested in the effect-based bioassays. Bioactivities were detected for multiple materials in six out of eight assays, the two assays showing no effects were NF kappa B and androgen receptor agonistic response. In essence, the detection rates of the tested non-polar extracts were 72% for antagonistic effects on the estrogen receptor, 72% for antagonistic effects on the androgen receptor, 47% for oxidative stress, 28% for agonistic effects on the estrogen receptor and 33% for genotoxicity. The bioequivalent concentrations ranges in extracts of 10 mg food contact article/mL cell culture media were: for oxidative stress from 2.45 to 5.64 mu M tBHQ equivalents, estrogen receptor agonistic activity from 1.66 to 6.33 rho M estradiol equivalents, estrogen receptor antagonistic activity from 1.21 x 10(-3) to 4.20 x 10(-3) mu M raloxifene equivalents and androgen antagonistic activity 0.08-0.46 mu M hydroxyflutamide equivalents. The extracts that were bioactive in multiple assays were: baking moulds, boxes for popcorn, infant formula/skimmed milk, porridge/flour mixes, pizza, fries' and hamburgers as well as packages for frozen food. Conclusion Non-polar extracts of food contact articles contain compounds that can activate molecular initiating events in toxicity pathways of high relevance to human health. These events included endocrine-disruptive activities, oxidative stress and genotoxicity. Effect-based methods proved to be a valuable tool for evaluating food package articles, as they can detect potentially hazardous effects of both known and unknown chemicals as well as potential cocktail effects.