November 2008

Cover Story

And you can eat it

Food packaging inks, adhesives proven safer from alliance study

Fast Forward

  • Alliance pushes FDA clearance for ultra violet curing.
  • Food packagers benefit: Fewer processes, greater productivity.
  • Alliance moves to boost clearance for more applications.
By Ellen Fussell Policastro

When most people open a new box of cereal, they might not think about all the testing the adhesives and inks go through for their safety. Inks, coatings, and adhesives have appeared on the outside of cereal boxes and other food packaging for years, but the new Food and Drug Administration (FDA) FCN 772 clearance will now allow food packaging manufacturers to use ultra violet (UV) or electron beam (EB) cured inks, coatings, and adhesives printing in ways they could not before because it was not explicitly FDA-cleared. Now that it is proven safe, manufacturers of food and beverage packaging can use these materials in packaging that may be in direct contact with food.

Contaminant migration

"With dry foods, there's very little risk inks will transfer from the outside packaging and carry contaminants into the food," said Ronald Golden, president of FocalPoint Consulting in Marietta, Ga., specializing in regulatory compliance with food safety and hazardous chemicals. "But unless packaging designers make packaging impermeable, with products such as cheese, meats, beverages, or moist bread, it's possible for fats or moisture from inside the package to reach the surface. Look at how grease reaches the surface of a popcorn bag. Once the moisture comes in contact with the ink, if it goes one way it can go the other way, carrying surface contaminants back into the food-a process known as migration," he said.

FDA regulations require a barrier layer that prevents migration. "If you have a layer of aluminum foil with printing on the outside, the expectation is none of the components of the inks, coatings, or adhesives on the outside will get inside," Golden said. "Materials outside the package do not necessarily require FDA clearance for food contact. But if manufacturers printed something on a thin layer of polyethylene, such as a bread bag, it's much easier for ink components to migrate to the inside. In this case, the material used to print outside would have to be FDA-cleared for its intended use."

Ultra-violet, electron beam curing

Inks, coatings, and adhesives often must undergo drying or curing using heat. This curing can also see use with UV/EB energy. Using UV/EB curing gives packages a higher quality and better performing finish than traditional finishes.

"Features such as holograms are created using UV technology," said Gary Cohen, executive director of RadTech, a nonprofit trade association that works on advancing UV/EB technologies out of Bethesda, Md. "There have been some marketing studies that show people will choose the brilliance of UV coating off the shelf before they will choose a product with other types of coating," Cohen said.

Plus, the UV/EB curing saves time and money. With conventional operations, you have to bake cans in an oven to dry. With this process, it is dried through the energy of UV light, and it is instantaneous, so you do not need the hot air of baking. "Anytime you have an oven you are emitting CO2, but our materials do not have solvents, so they are more environmentally friendly," Cohen said.

Although they bring quite a few advantages to packagers, in the past, few UV/EB curing materials explicitly had FDA clearance. Under those circumstances, you could use those materials in non-contact food packaging, such as on the outside of soda cans, cereal boxes, and soup cans, as long as they were never expected to migrate into the food.

FDA clearance

When any new material goes on the market for use in a food contact application, it must undergo FDA safety evaluations. Qualities such as complete composition, toxicity studies, and detailed chemical identity, as well as a list of all reagents and details of the manufacturing process, are put under the FDA microscope. If the FDA determines a new substance is safe for its intended use, the submitter may market the product under an effective FDA notice called a Food Contact Notification (FCN).

To help push this approval along, a self-funded group of 36 companies, called the RadTech Food Packaging Alliance, formed in 2005 to help obtain official FDA clearance for UV- and EB-cured inks, coatings, and adhesives based on acrylic (acrylate) chemistry. The companies included raw material suppliers, formulators, equipment manufacturers, converters, and packaging manufacturers. The key goal of the Alliance was to promote expanded use of UV/EB materials in food packaging. Members compiled pertinent information on three acrylate monomers, an epoxy acrylate oligomer, and a photoinitiator. The data included three new oral chronic toxicity studies that demonstrated no mutagenic effects over a range of acrylate monomers and an epoxy oligomer. These studies further confirmed these materials have low acute and chronic toxicity.

Food packagers benefit

Being extra cautious, users could have previously avoided putting these materials in their packaging because it was not FDA approved for food safety, even if it had a very low probability of coming into contact with food. The packager can now sell a more attractive package and do it cheaper because they can avoid extra packaging.

For some companies, the biggest advantage of the new clearance means "doing what they haven't been able to do in the past. When you have an insert, such as a prize in a cereal box, it has to be in a plastic wrap," Cohen said. "If it has a UV coating on it, it can be printed and dropped in the box directly," he said. This is a big productivity savings as well.

But the clearance is not what is so new, it is the recognition, Cohen said. It has always been safe. "I was at a trade show for fabrication of DVDs and CDs, and someone came up to me and said, 'I can't use your product because you don't have FDA clearance.' But once this product is cured, the average person is probably touching it everyday-opening your cereal, putting on your eyeglasses, walking on your floor. There's a misconception that it's dangerous. But it's widely used everyday. So clearly it's not FDA clearance that's new, it's the recognition of the safety of the material that's the key."

Additional FDA clearances will expand the potential for converters and food packagers to meet needs for improved packaging appearance, performance, efficiency, and sustainability in a highly demanding global market. "Moreover, we can expect to see additional, more diverse FDA clearances for a broader range of UV- and EB-curable materials," Golden said.

Food Packaging Alliance members can reference the Alliance FCN Master Files in new FCN filings so only limited new toxicity and migration data will be needed to supplement the existing FCN 772 studies, enabling faster FDA clearance for new acrylates and photoinitiators at a substantially lower cost. FCN 772 is just the beginning of a new chapter in the broader use of UV and EB curing for food packaging.


Ellen Fussell Policastro is the associate editor of InTech.  Her e-mail is

Details on FCN 772

Food Contact Notification (FCN) 772 received Food and Drug Administration (FDA) clearance for a group of acrylate monomers, an epoxy oligomer, and an optional photo-initiator after completing a 120-day FDA review this past spring. The FCN 772 food contact substance is a diacrylate mixture that can see use in coatings (including inks) or components of coatings on polymeric substrates, paper and paperboard, metal substrates, or as a component in adhesives, and may be used in contact with some foods.

The cured resins may include other substances permitted for the intended use by regulation under 21 CFR. This means materials that comply with an existing food additive regulation (21 CFR 175.105 Adhesives, 178.2010 Antioxidants and/or stabilizers for polymers, 178.3297 Colorants for Polymers, or with another FCN) can be combined with the FCN 772 materials to formulate an FDA-compliant ink, coating, or adhesive. The UV/EB-cured formulation also may contain materials that are the subject of an FDA or USDA sanction or approval prior to 1958 or materials that are deemed generally recognized as safe, or GRAS. Finally, the cured ink, coating, or adhesive may contain any uncleared components that are not reasonably expected to become a component of food (Threshold of Regulation principle). A formulator may combine the FCN 772 materials with already FDA-sanctioned components to offer inks, coatings, and adhesives suitable for food packaging, in most cases without having to obtain additional FDA clearances so long as the migration limitations are met under the intended conditions of use.

Acrylates used to manufacture UV/EB curing materials can cause a skin rash if they are mishandled, but past studies have proven they are not toxic to nerves, blood, or the liver (systemic toxicity). The FDA also requires proof the product is not toxic if ingested. The FCN Alliance ran oral mutagenicity studies with animals, testing whether eating these raw materials (not the cured films) caused changes in cells that could lead to cancer. The tests proved these UV/EB coating materials do not cause changes that would potentially lead to cancer, nor do they cause injury to bodily organs, or reproductive problems, or problems to a fetus.

The FCN Alliance also did extraction studies to see how much of these UV/EB curing materials could be expected to extract into food. The answer was not very much. Based on toxicity test and extraction test, the FDA concluded it was reasonable to use these materials in food packaging because there was no significant risk.

SOURCE: 2008 RadTech Report, "Sustainability Advantages of Ultraviolet and Electron Beam Curing," by Ronald Golden, RadTech member and consultant at FocalPoint Consulting in Marietta, Ga.


Migration limitations

The migration level for each Food Contact Notification (FCN) 772 substance used may not exceed 10 micrograms per square inch (µg/in2) (1 ppm), and the total nonvolatile extractables derived from the finished coating may not exceed 10 µg/in2, after correction for migration of each FCN 772 substance. These migration limits are far greater than those previously required under the FDA Threshold of Regulation principle.

Under FDA regulations, only Alliance members and their customers may claim FDA clearance for materials listed in FCN 772. The FDA has evaluated these materials, including their manufacturing process and possible contaminants. Food packaging manufactured from the same materials supplied by Alliance nonmembers would not have the benefit of this evaluation and would be considered adulterated.

For a complete listing of all effective Food Contact Substance Notifications, visit

SOURCE: 2008 RadTech Report, "Sustainability Advantages of Ultraviolet and Electron Beam Curing," by Ronald Golden, RadTech member and consultant at FocalPoint Consulting in Marietta, Ga.

List of FDA approval qualities

  • Physical and chemical specifications, including properties that could affect migration potential, such as solubility in food simulants
  • An environmental assessment
  • Analytical methods for determining the concentration of the food contact substance in food and food simulants
  • A detailed description of the intended use for the food contact substance, the types of food expected to be in contact, and the maximum time and temperature conditions of food contact
  • A detailed description of the intended technical effect of the food contact substance and the proposed use level
  • Detailed information sufficient to permit estimation of the daily dietary concentration of the food contact substance, including migration test data, migration test protocol, and estimated consumer exposure
  • A dossier of toxicological information and data on the new food contact substance(s) that conforms with guidelines given in the FDA "Toxicological Principles for the Safety Assessment of Food Ingredients" ("Redbook 2000")