Cardboard Packaging with Ethylene Vinyl Alcohol Copolymer (EVOH) as a Functional Barrier against Mineral Oil Migration.

Abstract

In 2012 a scientific opinion on the potential health risks of mineral oil contamination in food was published by the European Food Safety Authority (EFSA). Recycled cardboard is viewed as the main cause for this contamination and the packaging industry had been confronted with this problem. Regulation (EC) No 1935/2004 states that food contact materials will not transfer any constituent to food in quantities that can endanger human health. Additionally, all plastic materials must comply with Commission Regulation (EU) No 10/2011, which contains a positive list of allowed substances and their specific migration limit into food. Non-authorised substances can only be used when a functional barrier separates them from the food, which limits the migration of these substances to below a given detection limit. However, no harmonized regulation exists for paper and cardboard packaging materials. The industry is looking for possible functional barriers against mineral oils and methods to determine their functionality. Due to its outstanding barrier properties, ethylene vinyl alcohol copolymer (EVOH) is one of the key materials of interest. To evaluate its barrier performance against mineral oil, the breakthrough time was determined. A donor paper material spiked with a known concentration of mineral oils, was placed against the functional barrier and the transferred substances were extracted from a PE receptor material at regular intervals. This study shows that a multilayer film with 4.4 μm EVOH containing 32 mol% ethylene can compete with 20 μm polyamide (PA) and 12 μm (PET), as it shows only 1% breakthrough after 84 days at 60°C, which translates into a shelf life of over 10.6 years at room temperature. EVOH is a very suitable functional barrier for preventing mineral oil migration. More detailed research is ongoing to determine the efficacy of the barrier properties in specific packaging concepts.