Biedermann and colleagues published the results of their comparative migration study on March 25, 2013 in Food Additives & Contaminants: Part A. The researchers from the Official Food Control Authority of the Canton of Zurich, Switzerland compared the migration of mineral oils, phthalates and UV initiators from recycled board into various dry foods via different barrier materials, including polyethylene (PE), lacquered PE, polypropylene (PP), biaxially oriented PP (BOPP) and polyethylene terephthalate (PET). While PE lowered overall migration because it acted as a sink for the migrating substances, PET acted as a tight barrier and did not absorb any mineral oils. BOPP films delayed migration of mineral oils for about 2 months. Lacquered PP film lowered the level of mineral oils somewhat in comparison to the BOPP films. Of the photoinitiators, benzophenone was present at the highest concentration in the food and about 10-24% of the total amount present in the board migrated into the food. BOPP was an effective barrier for all photoinitiators other than benzophenone. There was no significant migration of UV initiators across the PET barrier. Of the phthalates, DiBP was present at highest concentrations (up to 0.54mg/kg) in the food, but only showed significant migration across PE and partially BOPP barriers.
The origin of the substances was confirmed in the extracts of the board material. The board was from recycled material, but unprinted. As such, migrating contaminants originated from the recycled material. Of the different dry foods, noodles generally showed lower migration than fattier foods, such as biscuits, but the difference in migration between the foods only amounted to a factor of 2. Mineral oils are present in printing inks used for non-food contact paper and board. Phthalates and photoinitiators are present in most inks. One type of mineral oil has been classified as a 1A carcinogen (Saturated hydrogen mineral oils), phthalates and many photoinitiators including benzophenone are of concern because of their endocrine activity in the body.
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 25, 2013). doi.10.1080/19440049.2013.786189