Printing inks and adhesives are present in foods
Printing inks and adhesives are commonly used on food packaging and their chemicals can migrate into foodstuffs. For instance, phthalates have been found to migrate from adhesive labels into fruits and vegetables (FPF reported). Scientists have identified 7413 substances that are known to be used in printing inks and adhesives applied to plastic food packaging, of which they ranked 636 as high priority substances due to their health concerns (FPF reported). But a broad assessment of ink and adhesive chemicals in food is missing.
Bram Miserez from Ciboris, Zwijnaarde, Belgium, and co-authors analyzed 52 food samples for the presence of 110 chemicals used in printing inks and adhesives. In their article, published on February 24, 2025, in the journal Food Chemistry, they reported that the majority of the analyzed food samples (39 samples) contained at least one of the target chemicals. Caprolactam (CAS 105-60-2) usually used in synthetic fibers and a known skin and eye irritant was one of the most commonly detected chemicals and its levels were above the legislative limit. One sample contained the primary aromatic amine and suspect carcinogen 2-methyl-5-nitroaniline (CAS 99-55-8). Overall, 16 of the 110 chemicals were present in at least one sample. Based on these results, the scientists called for the regular assessment of printing ink and adhesive chemicals in foodstuffs. Printing inks have previously been identified as priority products by the US state of Washington due to concerns that they release polychlorinated biphenyls (PCBs, FPF reported).
Upon method testing and optimization, Miserez and co-authors chose to extract the chemicals with acetonitrile or acetonitrile with 0.5 % acetic acid from the food matrices and to apply the extracts to liquid and gas chromatography mass spectrometry-based methods to analyze them for 110 target compounds. The researchers bought 52 foods packaged using adhesives and inks in Belgian supermarkets and online, including baby food, frozen vegetables, baked goods, and cheeses.
Regulation of printing inks in Europe
While there is no specific regulation for printing inks used in food contact materials under European community law, in Switzerland a positive list for printing inks has been in force since 2010, having undergone updates since then (FPF reported and here). The latest version, which came into force on the 1st of January 2025, lists 5355 substances for use in printing inks. Only a few have been evaluated toxicologically. In 2021, the Federal Council of Germany adopted its 21st Amendment to Consumer Goods Ordinance regulating printing inks and varnishes that directly or indirectly contact food. The amendment includes a positive list of approximately 600 chemicals and has a phase in period until the end of December 2026 (FPF reported).
References
Federal Ministry of Food and Agriculture (January 9, 2025). “Lebensmittelverpackungen und andere Lebensmittelbedarfsgegenstände.“ (in German)
Miserez, B., et al. (2025). “Gas and liquid chromatography-tandem mass spectrometry methods for the analysis in food of 110 chemicals from printing inks and adhesives used in food contact materials.” Food Chemistry. DOI: 10.1016/j.foodchem.2025.143475
Schweizerische Eidgenossenschaft (December 1, 2020). “Verordnung des EDI über Materialien und Gegenstände, die dazu bestimmt sind, mit Lebensmitteln in Berührung zu kommen (Bedarfsgegenständeverordnung“ (in German)
