Mineral oil migration creates new concern for packaging

Findings from a series of recent Official Food Control Authority Laboratory reports coming out of Switzerland have raised concerns over mineral oil migration occurring in packaging made with recycled content. The reports focused on technical grade oils that are largely linked to inks used in newspapers entering the recycling stream. This research builds on previous studies suggesting that technical grade mineral oils pose health concerns and are found to accummulate in the liver, lymph nodes and heart valves when ingested. There are additional concerns about aromatic mineral oils being carcinogenic, though their toxicology data remains uncertain.

Mineral oils, which are by-products of crude oil refinement, have a number of packaging applications including inks, adhesives, plasticizers and protective coatings. They may also be found in some recycled fibers used in paperboard packaging.

The Swiss reports documented instances where mineral oils leached from packaging materials made of recycled content, specifically grades containing newsprint, into food. As one example of how mineral oils can contaminate recycled fibers, mineral oils are present in petroleum-based inks as the vehicle that carries the pigments. The inks are applied to a surface such as newsprint, where the oils absorb, attach to pigments or attach to fibers. The newspaper is then purchased, read and discarded into the recycling stream. Some mineral oils will be removed in the recycling process. However, most of the oils absorbed into the fibers are likely to remain present in the reclaimed fibers. The recycled fiber may then be used in paperboard, a common material for food packaging, where migration can occur.

As advocates for increasing recycling rates and using recycled content, how do we address this issue?

First, there is still uncertainty about direct and indirect contamination sources. Direct contamination is common in baking, when mineral oils are used for applications like conditioning pans, knives and cutting boards. Agricultural practices also have direct applications for removing grain dust or fruit and vegetable coatings. Regulations are in place to ensure that these applications meet food-grade specifications, but this cannot be ruled out as a potential contamination source.

Indirect contamination occurs through mechanisms like migration. At this time, a knee-jerk reaction to limit applications or look to alternatives could do more harm than good. The uncertainties around contaminant sources and health impacts should, however, be grounds for further research.

As far as immediate actions to mitigate mineral oil exposure, current steps to reduce exposure include using functional bags or barriers made of PP, PET or aluminum layers. Additionally, some manufacturers are reducing the amount of recycled content they are using or shifting toward higher-grade recycled fiber. Petroleum-based ink alternatives are also being considered, though all of these options could add costs that cut into profit margins.

On a broader level, this brings up the issue of transparency. There is an underlying need for greater transparency about the use of chemicals throughout all stages of production. This is not something specific to mineral oils or packaging, but it is applicable across all industry sectors and supply chains.

There is a need for better communication of product inputs and the impacts of these intended applications. Such information could lead to proactive solutions in the future and avoid recalls while reducing a company's exposure to risk and supply chains. Policy development should also be included in this discussion. Europe appears to be at the forefront of regulation and policy development while the rest of us continue to play catch up. Furthermore, universal policies could help to mitigate frustration and confusion among industry members and help ensure product safety.

Source