Potential migration of diisopropyl naphthalenes from recycled paperboard packaging into dry foods.

The results of a study of the potential migration of diisopropyl naphthalenes (DIPN) from recycled paperboard packaging into some types of dry solid foodstuffs are reported. Paperboard diskettes containing different DIPN concentrations were prepared and put into contact with four types of dry solid foodstuffs, having high specific surface areas and different lipid contents. At regular intervals the DIPN content in the foods was determined. Two migration mechanisms have been proposed and verified. The first one relates to the direct contact existing between paperboard and foodstuff. The second one refers to the indirect contact between paperboard and food, controlled by an air space created above the paperboard into which the DIPN has diffused. Both mechanisms occurred and the migration depended on different factors: the contact time, the characteristics of the foodstuffs and the DIPN content in the cellulose-based matrix. However, only very low levels of contamination in the foodstuffs occurred in migration. As a consequence, this report also considers possible limitations which could be applied to the content of carbonless copy paper in packaging paperboard formulations.