Henkel presents its Adhesin A 78 series, a new generation of plasticizer-free dispersion adhesives for packages
The latest reports on the plasticizer diisobutyl phthalate (DIBP), which can migrate from paper and board packages and accumulate in the packaged foods, have alerted food and packaging manufacturers. The plasticizer can come from sources such as dispersion adhesives, which are frequently used in the packaging industry. To protect the consumer from possible risks, Henkel has developed novel dispersion adhesives that are entirely free of plasticizer.
Dispersion adhesives are prominent in the production of paper and board packages. Of these, so-called homopolymeric polyvinyl acetate dispersions are widely used and have been established for many years in the industrial bonding of paper. So that the adhesive can form an elastic film on paper, the formulations usually contain a plasticizer such as diisobutyl phthalate (DIBP). Although there are as yet no scientifically based limit values for assessing the transfer of DIBP to foods, DIBP is similar in terms of structure and action to the substance di-n-butyl phthalate (DnBP), which is considered to be toxic to reproduction, i.e. capable of causing harm to fetuses and impair fertility.
Risks from the migration of plasticizers in foods Measurements of board-packaged foods have revealed DIBP in concentrations of up to 5 milligrams per kilogram of food, as Germany's Federal Risk Assessment Institute (BfR) reports. This is critical in the event of contact with fat-containing foods and foods of a powdery or fine-grained consistency, such as baking mixtures and rice. The DIPB detected in foods, however, does not come directly from the package's bonds, but from the paper and board itself. This is because, when old packages are recycled, the plasticizers contained in the dispersion adhesives enter the paper cycle and can accumulate in the paper fibers. The paper mills have no way of extracting the plasticizers. Since the share of recycled fibers used in paper production is constantly rising, the share of entrained DIBP is also growing.
Immediate action taken After announcement of the possible risks caused by the migration of DIBP from dispersion adhesives in recycled paper, Henkel acted immediately. First, the existing adhesives formulations for packages were changed over to safe plasticizers. And, in addition, Henkel has developed its Adhesin A 78 series, an entirely new generation of plasticizer-free dispersion adhesives. This is a copolymer system whose formulation largely consists of renewable raw materials. Technically, the plasticizer-free adhesives meets all the usual industrial requirements for the bonding of folding boxes, corrugated board boxes and paper packages, including large-area lamination. Product variants are available for different application systems such as rollers and nozzles. Adhesin A 78 products are also highly economical.
Food contamination can be avoided In the packaging industry, the interest in alternative dispersion adhesives is enormous. Despite the lack of scientifically founded limit values for assessing the migration of DIBP from packages to foods, the BfR now recommends that 1 milligram of DIBP per kilogram of food should not be exceeded, with a maximum of 0.5 milligrams for baby food. Since the adhesives of the Adhesin A 78 series are entirely free of plasticizers and thus do not contain any DIBP, the contamination of food can now be entirely avoided. In accordance with BfR recommendation XIV (synthetic dispersions), these adhesives are suitable for direct contact with foods and reduce the accumulation of DIBP in recycled paper.
Change over now to plasticizer-free packaging adhesives Henkel advises its customers to anticipate the expected legislation and not just to shift to adhesives with alternative plasticizer strategies, but to change over immediately to plasticizer-free dispersion adhesives. Reputable food manufacturers and fast-food chains have already responded by having their packages produced with adhesives from the Adhesin A 78 series and confirm that changeover is technically unproblematic. In terms of sustainable consumer protection, dispensing entirely with plasticizers in packaging adhesives is thus the best solution.