The Regulation of Printing Inks in the United States
Inks are used for printing on food packaging in a number of ways. They are used, for example, in printing on the exterior of cardboard boxes that hold food, in reverse printing on the inside of food packages, and in printing inserts that are intended to be placed inside a package, in contact with the food.
Because of the variety of uses–and, thus, the many different food-contact scenarios that may be presented–an understanding of the regulatory systems that apply to printing inks is necessary not only for companies that manufacture those inks, but also for manufacturers of packaging materials and converters, and for food producers.
In the United States, the use of printing inks in food packaging materials is subject to the laws and regulations administered by the U.S. Food and Drug Administration (FDA), including the Federal Food, Drug, and Cosmetic Act ("the act"). The act requires that these materials be manufactured under good manufacturing practices, and that they be safe and suitable for the intended use.
Inks as Food Additives
In addition to the general manufacturing and safety requirements, other requirements may apply, depending on the intended use. Most significantly, if the use of the printing ink poses a "food additive" situation, then the use must be covered by a food additive regulation, an effective Food Contact Notification (FCN), or a Threshold of Regulation exemption letter; otherwise, the use must fall within an exemption from the need for such clearance.
The act defines a food additive as "any substance the intended use of which results or may reasonably be expected to result ... in its becoming a component ... of any food... if such substance is not generally recognized ... to be safe" or prior sanctioned. (See Section 201(s) of the act.) In most cases, a printing ink – intended for use in a food packaging application in which the ink may reasonably be expected to become a component of food – is considered a food additive.
Inks typically are made up of colorants, binders, and carriers. No single regulation identifies the inks that are permitted for use on food packaging, although many ink components are cleared under 21 C.F.R § 178.3297 ("Colorants for polymers") or, if used in paper applications, under 21 C.F.R. § 176.170 ("Components of paper and paperboard in contact with aqueous and fatty foods"). Colorants also may be permitted for their intended use under a Threshold of Regulation exemption, a prior sanction, or a Food Contact Notification.
Clearances for color additives used in direct food applications also should be considered because, based on the color additive clearance, it may be possible to determine that the color additive also is expressly permitted for use in indirect applications such as packaging. For example, 21 C.F.R. § 178.3297(d) specifically states that "[c]olor additives and their lakes listed for direct use in foods, under the provisions of the color additive regulations, ... may also be used as colorants for food-contact polymers."
Other components of printing inks may be the subject of separate "stand-alone" regulations. For example, a polyolefin carrier for the ink would be covered by 21 C.F.R § 177.1520 ("Olefin copolymers").
Even if a clearance exists in the food additive regulations for each of the components in an ink, it still is necessary to consider whether the regulatory clearance applies to the specific use being contemplated. For example, high purity furnace black (HPFB) is specifically cleared under 21 C.F.R. § 178.3297 for use in polymers, but HPFB is not specifically cleared for use in paper. Whether the regulation permits the use of a component in a resin should also be considered. For instance, CI Pigment Red 38 is specifically cleared under 21 C.F.R. § 178.3297 only for use in rubber. In addition, limitations on food types, temperatures, and use levels may apply.
Clearance Unnecessary in Other Circumstances
In situations where the ink is not reasonably expected to become a component of food when used as intended, the ink is not considered a food additive. In such a case, it is unnecessary to identify an explicit regulatory clearance, such as a food additive clearance, a Food Contact Notification, a Threshold of Regulation exemption, a prior sanction, or GRAS status.
When a functional barrier exists, the use of an ink on food packaging may not present a food additive situation. Whether a functional barrier exists depends upon several factors, including the nature and thickness of the material that separates the ink from the food, the formulation of the ink, and the time and temperature of exposure to the ink.
Nor does a food additive situation exist when no migration to the food is expected from the ink. "No migration" may be demonstrated by migration testing, 100 percent migration calculations, or diffusion calculations that model migration testing.
When a functional barrier exists or a "no migration" position is appropriate, the ink is not properly considered to be a food additive; thus, provided that it is safe for the intended use, it may be used in the absence of an explicit regulatory clearance in full compliance with the act.
Because formulated printing inks, per se, are not covered under a single regulation, each ink and intended use presents a unique situation with respect to its FDA status. The foregoing discussion, however, demonstrates that there may be several options for establishing a suitable FDA status for a particular printing ink even when there is no applicable food additive regulation that specifically clears the intended use of the ink.