October 10, 2012
Author: Greta Stieger

Printing inks

Printing inks in food contact materials

Printing inks on food packaging materials are used for consumer information as well as for marketing purposes. Inks are used with many different packaging materials. As such, plastics, paper, board and cork may be directly printed on. The printing inks may migrate onto the internal surface in contact with food through off-set migration. Some materials such as glass and plastic may also be dyed themselves. Further, packaging material can be equipped with printed etiquettes, such as in the case of PET bottles, or PS trays and cups. Finally, the use of recycled paper can mean that inks may be present within the bulk material. The biggest concern regarding recycled paper is the presence of mineral oil. Due to the non-discriminatory recycling of food contact paper and board and paper and board used in other applications, mineral oils will mix into the bulk material even if mineral oils are not used on food packaging materials [1-3].

The migration of printing inks depends on the material properties. As such, carton and board have a high permeability whereas glass has no permeability.

Studies have found printing inks in food stuffs since the late 80s. In 1989 Castle et al. reported plasticizers in foods [4], and since UV initiators, benzophenones have summed themselves to the list [56].

Several thousand different compounds can be used in printing inks posing a significant challenge to regulation and enforcement.

Switzerland is the first country to issue a positive list for printing inks (in force since March 2010), which contains more than 5000 substances.

In the EU food contact materials are regulated under the EU Framework Regulation EC 1935/2004on materials and articles intended to come into contact with food, which allows for further regulation being made on printing inks. Printing inks used on polymer based materials are regulated under regulation EC 1282/2011 on plastic materials. Yet, for all other food contact materials to this point no specific regulation on printing inks used in food contact materials has been enacted under European community law. However, the Report of the EFSA Scientific Cooperation (ESCO) Working Group on non-plastic Food Contact Materials includes an inventory list of substances used in non-plastic food contact materials, including printing inks[7]. While this report may be used to inform other panels within EFSA, it does not aim to produce a Scientific Opinion, which could inform action by the European Commission.

In the US, printing inks are regulated in the Code of Federal Regulations under Title 21 on food and drugs, Part 176-186 (21 C.F.R. Parts 174-186) and further fall under specific regulations depending on their use. If they have been cleared as a substance, which Generally Recognized as Safe (GRAS) a company does not need to notify the FDA of its use in a food contact application (21 C.F.R. Part 184). In 1995 the FDA further adopted the Threshold of Regulation rule, which allows non-carcinogenic substances having a dietary concentration below 0.5ppb to be exempted from the authorization process. Further, if the substance has been previously regulated as a direct food additive, and the use in food contact materials will not result in an exposure above 1% of the ADI, it can also be exempted. If the substance can reasonably be expected to become a component of the food stuff, it is regulated under the Food Additive Directive. Colorants that are permitted for use in food are also permitted for use in the printing of packaging materials. Some printing inks, such as high purity furnace black for use in polymers (21 C.F.R. § 178.3297), may also be cleared in separate regulations[8].

Reference

1.         Biedermann, M. and K. Grob, Is recycled newspaper suitable for food contact materials? Technical grade mineral oils from printing inks. European Food Research and Technology, 2010.230(5): p. 785-796.http://dx.doi.org/10.1007/s00217-010-1223-9.

2.         Droz, C. and K. Grob, Determination of food contamination by mineral oil material from printed cardboard using on-line coupled LC-GC-FID. Zeitschrift für Lebensmitteluntersuchung und -Forschung A, 1997. 205(3): p. 239-241.http://dx.doi.org/10.1007/s002170050158.

3.         Lorenzini, R., et al., Saturated and aromatic mineral oil hydrocarbons from paperboard food packaging: estimation of long-term migration from contents in the paperboard and data on boxes from the market. Food Additives & Contaminants: Part A, 2010. 27(12): p. 1765-1774.http://dx.doi.org/10.1080/19440049.2010.517568.

4.         Castle, L., A. Mayo, and J. Gilbert, Migration of plasticizers from printing inks into foods.Food Additives and Contaminants, 1989. 6(4): p. 437-443.http://dx.doi.org/10.1080/02652038909373802.

5.         Bradley, E.L., et al., Printing ink compounds in foods: UK survey results. Food Additives and Contaminants: Part B, 2012: p. 1-11.http://dx.doi.org/10.1080/19393210.2012.725774.

6.         Ash, M. and I. Ash, Handbook of Food Packaging Chemicals and Materials (2nd Edition), Synapse Information Resources, Inc.http://www.knovel.com/web/portal/browse/display?_EXT_KNOVEL_DISPLAY_bookid=2193.

7.         EFSA (2011). Report of ESCO WG on non-plastic Food Contact Materials. Retrieved January 14, 2013 from http://www.efsa.europa.eu/fr/supporting/pub/139e.htm

8.         Baughan, J.S. and D. Attwood, Food Packaging Law in the united States, in Global legislation for Food Packaging Materials, R.V. Rinus Rijk, Editor. 2010, Wiley-VCH: Weinheim. p. 223-239

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