The other type of list, a “positive” list, limits ink formulation only to those items on the list. This is a very conservative approach, which seems to result from significant pain incurred by CPGs as a result of the contamination issues. However, it is very limiting for all, as it prohibits the use of any new or potentially better raw materials without express approval.
This is a difficult time. The CPGs got burned, some badly, because of food contamination issues. The reaction to this problem has been to micromanage ink formulation as a defensive strategy. This likely will be found to be, at some point, an over-reaction as it limits the improvement options (performance and cost) of printing inks. We’ll all have to work through this over time.
A large percentage of food packaging print is for secondary packaging. This means that the food is sealed in some type of interior container which is itself placed in the printed container. This has been a growing trend, especially in frozen foods, and greatly reduces the risk for any food contamination from ink. For other foods, such as ice cream, juices and some dairy products, the print is on the outside of primary packaging, with the food product in contact with the non-print side of the package. In these cases, significant care must be taken to make sure that the ink is properly formulated, that the printing is done properly, that the inks and coatings are fully dried/cured, and that no other materials (fountain solution, press wash etc.) contaminate the inside of the package. It takes a team approach, including the ink maker, the substrate manufacturer, the printer and the print buyer. This is a stable process that has resulted in safe and attractive food packaging for many years, but it must be done correctly all the way through.