Label adhesives and food safety: Enjoying treats with no regrets

• Substance migration back on the agenda – Foodwatch identifies petroleum residues in confectionery. 
• Another case that illustrates the importance of low-migration packaging, says HERMA
• HERMA has developed an extremely low-migration label adhesive without any resins that offers exceptionally high adhesion straight away, even in demanding conditions.

Headlines are once again pointing to foods that have evidently been contaminated by migrating substances. The current affairs weekly Der Spiegel recently reported on petroleum residues in chocolate bars and other confectionery produced by leading manufacturers (http://www.spiegel.de/gesundheit/ernaehrung/foodwatch-findet-mineraloel-spuren-in-ferrero-kinder-riegel-a-1100882.html). The magazine attributes the findings to the consumer organisation Foodwatch. Although the actual origins remain unclear, investigations are focusing primarily on carton materials and printing inks. Labels and their adhesives are regularly implicated in such cases as well, however, especially when the revelations concern foods such as chocolate, cheese or sausage. The fat content of these foods can facilitate the unintentional diffusion of substances from the packaging, printing ink or adhesive.

"This is another case that illustrates the importance of low-migration packaging," insists Dr. Thomas Baumgärtner, managing director of self-adhesive materials specialist HERMA. He continues, "As a general rule, dispersion and water-based (acrylic) pressure-sensitive adhesives produced by HERMA for food labels are non-hazardous to health." He points out, however, that migration should be ruled out as far as possible with these products as well. HERMA is now causing a minor sensation with an entirely resin-free adhesive for labels that are required to offer extremely high adhesion as soon as they are applied. In the absence of resins, HERMAsuperTack (63Vst) is an exceptionally low-migration adhesive and has been approved for contact with dry, moist and fatty foodstuffs. In technical terms, testing has shown that the adhesive satisfies the rating criteria for correction factor 2. Within this category of adhesives, it could not be any closer to the zero-migration mark. HERMAsuperTack can therefore be used with labels that are to be applied to any food packaging without the risk of any significant migration of adhesive constituents into the food.

HERMA's multi-layer technology makes it possible to dispense with resins for this type of application without diminishing adhesive performance. Thanks to its broad scope, moreover, the adhesive can even be used in conjunction with labels that are applied in temperatures of minus 20 degrees Celsius. Apart from the food segment, it can also overcome a variety of labelling problems elsewhere – HERMAsuperTack is compatible with surfaces that are moist, greasy or even slightly soiled, and with plastic transport crates, which are notoriously difficult to label.