On April 27, 2021, peer-reviewed journal Food Additives and Contaminants published a comprehensive literature review of chemical migration between food packaging and dry foods containing no surface fats or oils. The authors do not evaluate safety considerations but conclude that contaminants from food packaging regularly transfer to dry foods at a higher rate than the default maximum of 50 µg/kg that the US Food and Drug Administration (FDA) assumes for all dry foods with no additional testing requirement.
The review assessed over 150 scientific papers published within the span of 1983 and 2020 and standardized all the migration rates to units of µg/kg from commercial packaging studies as well as percent migration (%) of a substance from experimentally manipulated packaging. Despite differences in porosity, particle size, and fat content within the food, “migration occurred to some extent to all types of dry foods noted in this review: pastas, baking mixes, rice, breadcrumbs, cereals, tea, milk powders, and powdered infant formula.”
Contaminant migration was higher from paper and paperboard packaging than plastic. Because inks and other potential contaminants may be mixed into recycled paper, the authors suggest “continued research as well as vigilance [towards] recycled paper and paperboard used for food packaging in the future” (FPF reported). Liners between food and paper packaging “reduce the migration of many compounds [but] migration may still occur from paper and paperboard through multiple layers of packaging, particularly inner linings made of low-barrier materials (polyethylene (PE), paper, or paper laminated with PE or ethylene-vinyl acetate (EVA)).” Barrier materials such as aluminum, PET, and polyamide (PA) stopped more contaminant migration from paper to food, but any liner material may also contain substances with the potential to migrate (FPF reported).
The review also supports the commonly held understandings that changes in temperature have a significant effect on migration, even greater than the length of contact, and higher fat content within a food particle leads to more contaminant transfer.
The authors suggest more studies of contaminant migration into dry foods are needed and give advice on improving the labor intense studies. They found the food simulants Tenax and Porapak effectively represented migration to dry foods. However, “in contrast to the cost and laborious preparation required for the two polymer simulants, the use of real foods (such as rice, sugar or baking mix) may be a more accessible and cost-effective alternative that opens the door to using larger food sample sizes.”
JH. Urbelis, JR. Cooper (April 27, 2021). “Migration of food contact substances into dry foods: A review.” Food Additives and Contaminants