An article published on Aug 14, 2018, in the peer-reviewed journal Food Additives & Contaminants: Part A reported on the use of activated carbon to prevent migration of chemicals from recycled paperboard into food.
Maurus Biedermann and colleagues from the Official Food Control Authority of the Canton of Zurich, Zurich, Switzerland, used silicone paper as a dry food simulant to analyze chemical migration from Catcherboard MB12® from Smurfit Kappa, which is “a recycled paperboard incorporating activated carbon to reduce the release of contaminants into food.” The presence of activated carbon allows reducing the migration rate because “sorption into activated carbon increases the concentration ratio paperboard/food,” the authors explain. They found that in Catcherboard MB12® the concentration ratio was increased by a “factor of at least 1000 compared to recycled paperboard without activated carbon,” and this is “sufficient to meet the 1% criterion proposed for barriers.”
However, activated carbon, as any sorbent, has limited sorption capacity. The authors observed that the capacity of activated carbon in Catcherboard MB12® was exceeded after it was additionally loaded with 4 g of surrogate substances per kg paperboard. At this load and above, “concentration ratios were reduced and the release of paperboard constituents increased.”
Not only “constituents from the printing inks,” but also volatile substances absorbed by packaging from the packed food itself, can be expected to consume the sorption capacity, the authors explain. Their experiments, however, confirmed that “for the large majority of the dry foods, . . . [the] amounts [migrating from food into paperboard] were clearly below the capacity limit even under the exaggerated assumption of total transfer.”
Based on their study, the authors thus conclude that “recycled paperboard with activated carbon is promising for respecting the 1% criterion stipulated for functional barriers to avoid food contamination from recycled paperboard.”
Biedermann, M., et al. (2018). “Activated carbon added to recycled paperboard to prevent migration into food: approach for determining efficacy and first results.” Food Additives & Contaminants: Part A (published Aug 14, 2018).