Migration of mineral oil from unprinted recycled paperboard can significantly be reduced by using an appropriate inner bag. This is the main result from a carefully designed new scientific study published March 21, 2013 in the peer reviewed scientific journal Food Additives &Contaminants: Part A (Biedermann et al. 2013) and reported on by the Food Packaging Forum (article). Researchers from Switzerland and Germany examined migration of residues from recycled paperboard into 6 different foods over the course of 9 months, stored at room temperature. Chocolate cookies, rice, bread crumbs, oatmeal, polenta and noodles were tested after 2, 4 and 9 months for migration of several printing ink compounds, phthalates, as well as mineral oil substances. Mineral oil aromatic hydrocarbons (MOAH) are particularly of concern because of their suspected carcinogenicity. They have been found to migrate from recycled paperboard into foods in the ppm range (mg per kg food).
The present study identified a polyethylene terephthalate (PET)/polyethylene (PE) film to be the most efficient barrier for mineral oil migration. Printing ink components, like benzophenones, and phthalates were also studied. Foods that were packaged directly in the recycled paperboard showed high migration, for butyl phthalate even above the German currently permitted level of 0.3 mg/kg.
Biedermann, M., et al. (2013). “Migration of mineral oil, photoinitiators and plasticizers from recycled paperboard into dry foods: a study under controlled conditions.” Food Additives & Contaminants: Part A (published online March 21, 2013).