The Use of Colorants in Packaging Applications: An Overview

Colorants used in packaging applications have suffered a long and checkered history. In our experience, few other classes of food-contact substances can be said to have endured the regulatory twists and turns that colorants have experienced since the issuance of the Food Additives Amendment of 1958.  

With respect to colorants for polymeric packaging alone, several U.S. Food and Drug Administration "extension lists" of permitted colorants, five rulemakings spanning more than three decades, multiple FDA advisory opinions to companies on the use of particular colors, and numerous objections, petitions for reconsideration, and hearings requests objecting to FDA's various positions were issued by or filed with FDA before a final regulation was issued, consolidating all the colors FDA has found safe in a single regulatory listing. (See 21 C.F.R. § 178.3297 ("Colorants for polymers").)

Adding to the general muddle that has infused FDA's historical treatment of colorants is the fact that FDA's statutory authority for regulating colorants for food packaging lies in the agency's Food Additives Amendment of 1958 rather than the Color Additives Amendment of 1960. While both amendments to the Federal Food, Drug, and Cosmetic Act regulate colors, the regulatory scheme applicable to a colorant's use depends entirely on the function and intended use of the substance.

As a general rule, colorants used in food packaging are permitted by virtue of the Food Additives Amendment of 1958 and, hence, subject to FDA's requirements for food-contact substances under 21 C.F.R. Parts 170 et seq., as well as FDA's Food Contact Notification program[1]. Colorants that literally color foods, drugs, cosmetics, and some medical devices, and that are visible to the naked eye, are considered by the agency as "color additives" that must be listed in an applicable Color Additive Regulation under 21 C.F.R. Parts 73 and 74.

Colorants in Food Packaging

The Federal Food, Drug and Cosmetic Act defines a food additive as "any substance the intended use of which results or may reasonably be expected to result, directly or indirectly, in its becoming a component or otherwise affecting the characteristics of any food,. . . if such substance is not generally recognized. . .to be safe under the conditions of its intended use; except that such term does not include - . . . (4) any substance used in accordance with a sanction or approval" issued by either FDA or the U.S. Department of Agriculture prior to 1958.

Based on this definition and its exclusions, a number of options are available to market food- contact materials, including colorants used to color the package, without obtaining FDA's preclearance. That is, as with any food-contact substance, a colorant is not considered a food additive and does not require premarket clearance by FDA if it is: (1) not reasonably expected to become a component of food, (2) considered "generally recognized as safe" (GRAS) among experts qualified by scientific training and experience to evaluate its safety, or (3) used in accordance with a sanction or approval issued prior to 1958 by either FDA or the USDA. If, however, a colorant falls within the definition of a food additive, the act requires that its use be authorized by an effective Food Contact Notification (FCN), a food additive regulation, or be the subject of a "Threshold of Regulation" exemption letter.

Colorants Used in Polymers

Colorants and optical brighteners explicitly cleared by FDA for use in polymers are listed in 21 C.F.R. § 178.3297 ("Colorants for polymers"). As part of the rulemaking process for this listing, which became final in 1991, FDA stated erroneously that, based on Fick's First and Second Laws of Diffusion,"[2] that all colorants used in packaging materials are food additives as they "will migrate at some level to the food with which the polymers come into contact." 56 Fed. Reg. 42927, 42928 (Aug. 30, 1991).

After industry vehemently objected to this position as contrary to the findings in Monsanto Co. v. Kennedy[3] in formal objections and petitions of reconsideration of the final rule, FDA ultimately acknowledged in its 1993 final rule that the agency "did not intend to imply that firms could not make their own determination as to whether a particular use of a specific substance does not meet the definition of a food additive" (58 Fed. Reg. 67318, 67320 (Dec. 21, 1993)). In other words, as has been the case since the passage of the 1958 Food Additives Amendment, industry may continue to determine on its own the food additive status of colorants in food-contact polymers by, for example, testing that determines that a particular color is not expected to migrate to food and is hence not a "food additive" subject to premarket regulatory clearance.

Various colorants are also permitted for use in polymers by virtue of Threshold of Regulation listings (see http://www.fda.gov/Food/IngredientsPackagingLabeling/PackagingFCS/ThresholdRegulationExemptions/default.htm) or applicable Food Contact Notifications (see http://www.fda.gov/Food/IngredientsPackagingLabeling/PackagingFCS/Notifications/default.htm). While the former allows any manufacturer to utilize the colorant provided the limitations of the threshold listing are met, Food Contact Notifications only allow the submitter of the FCN and its customers to rely on the notification.

Colorants used in Paper and Paperboard

Twenty-seven colorants are cleared for use with paper and paperboard under 21 C.F.R. 176.170 ("Components of paper and paperboard in contact with aqueous and fatty foods"). These materials are automatically permitted for use in contact with paper and paperboard in contact with dry foods as well, under 21 C.F.R. § 176.180, by virtue of the cross-referencing language of 21 C.F.R. § 176.180(b)(1). However, colorants cleared for use in polymers under 21 C.F.R. 178.3297 are not permitted for use in paper and paperboard applications.

Nonetheless, the prevalence of paper and paperboard (versus polymers) as food-contact materials before the passage of the 1958 Food Additives Amendment suggests that additional colorants are cleared for use with paper or paperboard as "GRAS" or "prior sanctioned" substances. (For a more complete explanation of the appropriate FDA status of these pre-1958 colorants when used in paper and paperboard food packaging, please see the Packinglaw.com article, "The Pre-1958 List: Safe Haven for Colorants in Use Prior to Enactment of Food Additive Amendments," (link can be found below).

Inks

The only express FDA regulation of inks is contained in 21 C.F.R. § 73.1, a direct "color additive" clearance that covers color additive diluents. That regulation permits the use of various inks for marking food supplements in tablet form, gum, and confectionery, as well as fruits and vegetables. Although FDA does not anywhere explicitly list permitted "inks" for use in polymeric or paper packaging for food-contact applications, FDA, in general, permits the use of inks in food-contact materials that are comprised of:

• substances listed in 21 C.F.R. § 73.1;[4]
• color additives cleared for direct use in food;[5]
• GRAS substances;
• substances regulated for use in food-contact material if the substance's use in the ink also complies with the applicable food-contact regulation. This would include materials cleared under 21 C.F.R. § 178.3297 provided the colorant was used in a polymeric-based ink; many ink components can also be found in 21 C.F.R. § 176.170, if used in paper applications;
• substances that are the subject of a prior sanction or approval issued by FDA or the U.S. Department of Agriculture; or
• substances that are separated from food by a "functional barrier," such as a lacquer over the ink, or otherwise are not reasonably expected to become components of foods.

Color Additives for Use Directly in Foods, Drugs, Cosmetics, and Medical Devices

The Color Additives Amendment of 1960 characterizes all color additives as unsafe for use in foods, drugs, devices, and cosmetics unless FDA explicitly preapproves the color additive for a particular use[6]. Moreover, FDA considers products to be adulterated if they contain color additives not expressly cleared by FDA for the intended use[7]. As amended, the act defines a color additive as a material that:

• (A) is a dye, pigment, or other substance made by a process of synthesis or similar artifice, or extracted, isolated, or otherwise derived, with or without intermediate or final change of identity, from a vegetable, animal, mineral, or other source; and
• (B) when added or applied to a food or cosmetic, or to the human body or any part thereof, is capable ... of imparting color thereto.
• 21 U.S.C. § 321(t)(1). (Emphasis added.)

Rather than automatically clear the 200 color additives already in use before the Color Additive Amendments, similar to the "prior sanction" given to food additives already in use prior to the 1958 Amendment, Congress placed all existing color additives on a provisional list[8]. Manufacturers were required to generate safety data demonstrating that the use of the color additive was safe for its intended use[9]. Subsequently, only about 90 of the original 200 were considered safe and cleared for use in food, drugs, and cosmetics[10]. Many of the remainder were withdrawn or de-listed[11].

The Color Additive Classification System

FDA regulations classify color additives into two categories: those FDA certifies by batch and those exempt from certification. Exempt color additives contain pigments derived from natural sources such as vegetables, minerals, or animals, and can be sold without prior FDA certification, but they must still meet certain specifications and purity requirements[12]. These are listed by FDA at Part 73 of the Color Additive Regulations. Certifiable color additives, on the other hand, are man-made colors derived from petroleum (sometimes called coal tar dyes); each batch of a certifiable color additive is tested by the FDA to ensure that the color meets established specifications[13]. Color additives that are subject to certification are found at Part 74 of the Color Additive Regulations. The three categories of certifiable color additives are:

• (1) Food, Drug & Cosmetic—color additives certified for use in food, drugs, or cosmetics;
• (2) Drug & Cosmetic—color additives certified for use in drugs and cosmetics; and
• (3) External Drug and Cosmetic—color additives certified for use in drugs and cosmetics that are applied externally.

Each certifiable color additive is identified according to its category and an FDA-assigned number, which identifies particular colors based on their formulation and hue. Together, the system permits accurate identification and labeling of colorants[14]. Of the three categories of color additives, FDA holds FD&C colorants to the highest level of scrutiny because they are approved for the widest variety of uses, including ingestion in food.

Even with an FDA regulatory clearance, a sample from every batch of a certifiable color must be tested and certified by FDA before it can be used in food, drugs, cosmetics, and some medical devices[15]. FDA does not recognize color additive clearances or certifications from any foreign country[16].

Medical Devices

The regulation of color additives in medical devices raises interesting questions regarding FDA jurisdiction. Although the 1976 Medical Device Amendments and the 1960 Color Additive Amendments do not give FDA explicit jurisdiction over colorants used in medical devices, FDA has interpreted Section 201(t) of the act by emphasizing the phrase "capable ... of" in an abstract sense. Accordingly, FDA has stated that a tint or pigment used to color a device will satisfy the "capable of" test and, hence, be a color additive if, "[i]t can impart color when it is added or applied to the human body, even though it cannot impart color to the body when it is used in a device."

Nonetheless, Section 721(a) of the act provides that colorants in medical devices are exempt from the need for a color additive regulation unless "the color additive comes in direct contact with the body of man or other animals for a significant period of time." FDA has reserved to itself the authority to assess the "significance" of the contact with the body in determining whether to require premarket clearance of a colorant used in a medical device. For colorants used in or on devices that are eligible for clearance under Section 510(k) of the act, FDA has chosen not to enforce the color additive requirements. So far, the agency has required colorants for medical devices to be the subject of Color Additive Regulations only when used in Class III devices requiring premarket approval.

[1] See "Fathoming Food Packaging Law Revisited," by Jerome H. Heckman (link below).

[2] Cran, J., The Mathematics of Diffusion, 2d Ed., pp. 2 - 4 (Oxford Press, London, 1976).

[3] 613 F.2d 947 (D.C. Cir. 1979). See also "Fathoming Food Packaging Law Revisited," supra.

[4] See "FDA's Colorants in Polymers Rule," Dr. Mitch Cheeseman, presented at CPMA Conference on "Color Pigments 1994: Legislation, Regulation and Innovation," Washington, D.C. April 6-7, 1994.

[5] Id.

[6] See 21 U.S.C. § 379e(a). An exception applies to materials that are used or intended to be used "solely for a purpose or purposes other than coloring." FDA's regulations note that, for this exemption to apply, the "material must be used in a way that any color imparted is clearly unimportant insofar as the appearance, value, marketability, or consumer acceptability is concerned." 21 C.F.R. § 70.3(g).

[7] See 21 U.S.C. §§ 342(c), 351(a)(4) and 361(e).

[8] See 21 U.S.C. § 379e, note.

[9] Id.

[10] See http://www.fda.gov/ForIndustry/ColorAdditives/default.htm

[11] Id.

[12] See http://ecfr.gpoaccess.gov/cgi/t/text/text-idxc=ecfr;sid=df0d2cc786cc4d2efd1ebf642c9a79fa;rgn=div5;view=text;node=21%3A1.0.1.1.24;idno=21;cc=ecfr

[13] Id.

[14] See 21 C.F.R. Part 74.

[15] See 21 U.S.C. § 379e (c).

[16] See http://www.gmp1st.com/BlueBook.pdf

[17] Letter from Thomas Scarlett, Chief Counsel, Food and Drug Administration to John B. Dubeck (Keller and Heckman) (Feb. 15, 1983).