Inks For Food Packaging

On behalf of its member companies, the National Association of Printing Ink Manufacturers (NAPIM) congratulates C&EN for highlighting an important issue relating to packaging in general, and food packaging in particular (C&EN, Aug. 31, page 11). The safety of packaged food and other goods is dependent upon the performance of the packaging, whether any materials leach from the packaging, and if so, in what quantity. If the packaging is not adequately designed or manufactured from appropriate materials, then leaching or migration of materials can occur, potentially resulting in noncompliance of the packaged goods.

Over the years, several components have been found to migrate from inappropriately specified printed packaging. NAPIM members have worked diligently to improve the safety of printed food packaging while allowing other technological improvements to be delivered to the consumer (longer shelf life, renewable/recyclable materials, in-pack processing, etc.). Such improvements include selection of raw materials with lower hazards and reduced levels of potentially hazardous components, such as elimination of pigments based on heavy metals and removal of polyaromatic hydrocarbons from mineral oils and carbon pigments. In addition, ink manufacturers have developed low-migration products and products formulated solely from Food & Drug Administration-permitted food additives.

However, despite these improvements, it is still possible for unwanted components from the print on the outer surface to transfer to the packaged foodstuffs under certain circumstances, whether by migration through the substrate or via set-off or vapor-phase transfer.

The level of transfer depends upon many variables and not just the composition of the ink. For example, the substrate, packaging design and construction, print design, press conditions and adequacy of drying, storage conditions, nature of the foodstuff, and any processing conditions will all influence the extent of transfer. The same ink printed under one set of conditions and packaging design will have a totally different migration profile and performance in different circumstances. Unfortunately, there is still some confusion in the packaging supply chain about the requirements and performance of printed packaging, and particularly about the concept of a functional barrier.

The NAPIM Food Packaging Committee, among its other work, recently produced a set of frequently asked questions covering printing inks for food packaging that discusses these issues in more detail to improve awareness of this subject. For more information, see www.napim.org.

James E. Coleman
Executive Director, National Association of Printing Ink Manufacturers
Woodbridge, N.J.