Coatings and Inks for Food Contact Materials

Coatings and Inks for Food Contact Materials

Author: Martin J. Forrest
ISBN 978-1-84735-079-4 

Rapra Review Report
Vol. 16, No. 6, Report 186, Soft-backed, 121 pages.
For many years, Smithers Rapra has carried out research projects for the UK Food Standards Agency (FSA). This review report has, as its origin, an FSA project on coatings and inks that was carried out at Smithers Rapra from 2005 until 2007. The objective of this project was to assess the potential for the migration of substances from coatings and inks that were used in food packaging applications. As a significant amount of work had already been carried out on coatings that were in direct contact with food (e.g., can coatings), a boundary was set that only coatings and inks in non-direct food contact situations would be considered. As the scope of this review report is greater than the Smithers Rapra project and, due to the limitations of this particular format, it has only been possible to include some of the information that was acquired during the course of the FSA project.

This report has attempted to cover all of the coatings and inks products used in food contact scenarios. Hence, direct and non-direct contact situations are included throughout the food chain, e.g., harvesting, processing, transportation, packaging and cooking. In practice, this encompasses an extremely wide range of polymer systems and formulations, and an emphasis has been placed on coatings and inks used in food packaging, as this is usually regarded as representing the most important application category with respect to the potential for migration to occur. With respect to food packaging, all three of the major material classes are covered, i.e., metal, paper and board, and plastic. In addition to a thorough introduction of the polymers and additives that are used to produce coatings and inks, there are also chapters covering the regulation of these materials, the migration and analytical tests that are performed on them to assess their suitability for food contact applications, the migration data that have been published, and the areas in the field that are receiving the most attention for research and development.

This report is one of a series of three. A report summarising the current situation of the use of rubber products for food contact applications was published in 2006 and a report reviewing the use of silicone-based materials (including rubbers, resins and liquids) with food will be published by Smithers Rapra shortly.

This report will be of interest to anyone who works with the packaging of food and beverages and also to those who are studying food packaging/processing.

The review is accompanied by around 400 abstracts compiled from the Polymer Library, to facilitate further reading on this subject. A subject index and a company index are included.

1. Introduction
2. Coating and Ink Products for Food Contact Materials
2.1 Polymers for Coatings and Inks
2.1.1 Acrylic
2.1.2 Alkyd resins
2.1.3 Amino Resins (e.g., urea-formaldehyde resins)
2.1.4 Epoxy Resins
2.1.5 Cellulosics
2.1.6 Polyesters – Saturated and Unsaturated
2.1.7 Polyurethanes
2.1.8 Rosin
2.1.9 Silicone Resins
2.1.10 Vinyl Polymers
2.1.11 Other Polymers (e.g., hydrocarbons)
2.2 Constituents of Coatings
2.2.1 Crosslinking Agents
2.2.2 Other Additives
2.2.3 Solvents
2.3 Constituents of Inks
2.3.1 Solvents
2.3.2 Plasticisers
2.3.3 Driers
2.3.4 Photoinitiators
2.3.5 Colorants
2.3.6 Other Additives
3. Coatings and Inks used in the Food Chain
3.1 Food Packaging
3.1.1 Packaging Types
3.1.2 Coatings Used in Metal Packaging (Tables 5 to 9)
3.1.3 Coatings and Adhesives for Flexible Packaging (Tables 10 and 11)
3.1.4 Inks for Metal Packaging (Table 12)
3.1.5 Inks for Paper and Board Packaging (Table 13)
3.1.6 Inks for Flexible Packaging (Table 14)
3.2 Harvesting and Processing of Food
3.3 Storage and Transportation
3.4 Presentation, Dispensing and Cooking
4. Application Techniques for Inks
4.1 Lithography
4.2 Flexography
4.3 Gravure
4.4 Inkjet
4.5 Influence of Substrate Type
4.5.1 Inks for Metal Packaging
4.5.2 Inks for Paper and Board
4.5.3 Inks for Flexible Plastic Packaging
4.5.4 Set Off
5. Regulations Covering the Use of Inks and Coatings with Food
5.1 Regulation in the European Union
5.2 Council of Europe (CoE) Regulations
5.2.1 Coatings
5.2.2 Inks
5.3 National Regulations within the EU
5.4 FDA Regulations
5.5 Other Considerations for Industrial Use

6. Assessing the Safety of Inks and Coatings for Food Applications
6.1 Global Migration Tests
6.2 Specific Migration Tests
6.3 Fingerprinting of Potential Migrants from Coatings and Inks
6.4 Determination of Specific Target Species in Coatings and Ink Products and in Food Simulants and Foods
6.4.1 Monomers, Solvents and Low Molecular Weight Additives and Breakdown Products
6.4.2 Oligomers
6.4.3 Plasticisers and Oil-type Additives
6.4.4 Polar Additives and Metal Containing Compounds
6.4.5 Cure System Species, Initiators, Catalysts and Their Reaction Products
6.4.6 Antidegradants, Stabilisers and Their Reaction Products
6.5 Sensory Testing
6.6 Toxicological assessment of migrants

7. Potential Migrants and Published Migration Data
7.1 Acrylates
7.2 Amines
7.3 Aromatics from Unsaturated Polyesters
7.4 Aromatics from Photoinitiation Reactions and Photoinitiator Additives
7.5 BPA and BADGE and Derivatives
7.6 Epichlorohydrin
7.7 Bisphenol A
7.8 Solvents
7.9 Plasticisers
7.10 Extractables from UV-Cured Coating for Cardboard
7.11 Potential Migrants

8. Improving the Safety of Inks and Coatings for Food Use
8.1 New Food Approved Pigments
8.2 Water-Based Systems
8.3 UV/EB Curable Systems
8.4 New Initiators for UV Curable Inks

9. Future Trends
9.1 Improvements in Recycling Systems
9.2 Biodegradability
9.3 Use of Coatings to Improve Barrier Properties of Food Packaging
9.4 Antimicrobial Systems
9.5 Laser Marking to replace Conventional Inks
9.6 Intelligent and Active Packaging
9.7 Applications of Nanotechnology
9.8 Developments in Analytical Techniques

10. Conclusion

Additional References

Sources of Further Information and Advice
Reference Books
Professional, Research, Trade and Governmental Organisations
Commercial Abstract Databases



Subject Index

Company Index