EXTENDO high-barrier films protect food against mineral oil migration. Photo: Taghleef Industries

Migration of Mineral Oils: solutions not sufficiently used so far

Food safety is a touchy topic and enjoys highest priority in the packaging industry. For some time now the problem of mineral oil residues in food caused by mineral-oil based inks has been broadly discussed in the public sphere and by policy-makers. Packaging companies have reacted to this at an early stage and offer forward-looking solutions for increased food safety.

Example 1: recycling paper and carton.

The mineral oil content of many types of recycling paper and cardboard could be clearly reduced in a short amount of time by consistent sorting and the use of wood pulp and fresh fibre.

Consistent sorting of contaminated waste paper and the addition of wood pulp and fresh fibre brought the mineral oil content in many recycling and cardboard types down fairly rapidly. Photo: Lautaberleise / The Grip

Example 2: barrier properties

The general rule for paper, carton and films: the better their barrier properties are the more effectively the migration of mineral oils into food can be prevented. As early as 2014 the two companies BASF and Omya developed a polymer-based barrier solution for packaging from paper and carton called: Coater-Ready-Barrier-Solution. This consists of pigments, additives and functional dispersions and protects against the migration of these disputed oils.

Algro Guard is the name of another solution offered by German packaging specialist Sappi. The paper-based barrier layer provides protection against oxygen, water vapour and also fat and mineral oils. Another advantage: a high percentage of the coating consists of renewable materials.

The developer and manufacturer of functional coatings and varnishes Weilburger Graphics also offers new options. In 2016 two low-migration varnishes were launched - specifically developed for food contact. Even when stacked they dry fast and score points with good stability and abrasion resistance.

Arab film producer Taghleef Industries has launched BoPP-Film Extendo – a migration-safe film that also boasts excellent sealing properties for aroma.

WEILBURGER Graphics launched two new low-migration varnishes at interpack 2017. Photo: WEILBURGER Graphics

Technology options

There are various technology approaches for improving the barrier properties of packaging including perfluorated carbohydrates. They are applied in a size solution, are oil and fat-resistant and suitable for mass production due to their cost efficiency. Recycling, however, is hardly possible. The same applies to the lamination of papers with barrier-tight polyethylene films. The migration properties are extremely good, but again recycling is only possible at great expense.

Starch-based barriers promise good properties against mineral oil but are susceptible to moisture. Chemical combine Dow recently presented a new product called Rhobarr130. This acrylate-based watery emulsion comes with good barrier properties.

These promising solutions presented by the packaging industry, however, can only take effect when used. But as long as food producers are not legally obliged to use packaging with mineral oil barriers the overall situation will presumably not change a great deal.