The purpose of this article is to explain how color additives are regulated in the United States, specifically the laws and regulations that apply to color additives, how the U.S. Food and Drug Administration (FDA) evaluates their safety and how FDA ensures their compliance with these laws and regulations.
A Regulatory History and Framework
U.S. regulation of color additives can trace its roots back to the Federal Food and Drugs Act of 1906, also known as the Pure Food and Drug Act. This watershed legislation prohibited the interstate commerce of adulterated and misbranded food and drugs in the U.S. The statute also prohibited the use of poisonous or deleterious colors in confectionary products and the coloring or staining of food in a manner that concealed damage or inferiority. The burden of proving that a food or drug was adulterated or misbranded was placed on the Bureau of Chemistry in the U.S. Department of Agriculture (USDA). In 1907, USDA published a list of seven synthetic organic dyes considered to be safe for use in food. This list was based on a study of 80 dyes then in use in food. These were the first “approved” color additives, and four of the seven dyes are still permitted today.
In 1927, the regulatory functions of the Bureau of Chemistry were transferred to a new organization named the Food, Drug and Insecticide Administration, which was shortened a few years later to the Food and Drug Administration. FDA was given regulatory oversight of foods and drugs, including the coloring materials used as ingredients. Passage of the Federal Food, Drug, and Cosmetic Act (FD&C Act) of 1938 added cosmetics and medical devices to the products regulated by FDA. The FD&C Act prohibited the use of most synthetic organic dyes and pigments, historically known as coal-tar colors, in foods, drugs and cosmetics unless they came from batches certified by FDA to be safe for the permitted uses. (“Coal tar” refers to a byproduct of coal processing that was first used to produce the dyes. Today, these types of color additives are synthesized from coal or petroleum sources. “Batch certification” refers to FDA’s process of analyzing representative samples of manufactured batches to verify compliance with their identities and specifications.)
In addition to mandating certification of coal-tar colors, the FD&C Act required that foods containing artificial colors must declare that fact on their labels (equivalent requirements for drugs and cosmetics were established later) and required FDA to establish regulations for listing permitted coal-tar colors and certifying new batches. The FD&C Act also provided an important exception to the listing and certification requirements for the coal-tar colors used in hair dyes as long as the hair dye products had a caution statement indicating that the product may cause skin irritation and instructions for performing a skin test.
The coal-tar colors permitted for use in foods, drugs and cosmetics (other than hair dyes) began to be listed in the recently established Code of Federal Regulations (C.F.R.) in 1938 and began to be certified in 1939. A new nomenclature was devised for the certified coal-tar colors consisting of the prefix “FD&C” to indicate food, drug and cosmetic use, “D&C” to indicate drug and/or cosmetic use, or “Ext. D&C” to indicate external drug and/or cosmetic use. The prefix is followed by the specific color, a number and, if applicable, the term “Lake.” (In this context, a lake is an insoluble pigment formed from a water-soluble dye precipitated onto a substrate such as alumina.) An example of a common certified color additive is FD&C Yellow No. 5.
The regulation of color additives was further enhanced by the 1960 Color Additive Amendments to the FD&C Act, which defined the terms “color additive” and “unsafe color additive.” The statutory term “color additive” now included vegetable, mineral and animal sources as well as coal-tar sources. The amendments required premarket approval by FDA for all color additives added to foods, drugs and cosmetics, provided exemption from certification for color additives not deemed by FDA to need that requirement, required FDA to establish a provisional list of color additives in use at that time to reevaluate their safety and required the agency to establish a petition process for permanently listing all color additives it determined to be safe and suitable for their listed uses. Additional adulteration provisions stated that a color additive is unsafe for use in food, drugs and cosmetics unless there is an authorizing regulation or exemption in effect.
The 1960 Color Additive Amendments established four factors that FDA must consider in determining the safety of a color additive: probable consumption or exposure from use; cumulative effect in the diet; appropriate safety factors for the use of animal experimentation data; and the availability of analytical methods for determining its purity and acceptable levels of impurities.
The term “color additive” is defined in Section 201(t) of the FD&C Act as 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 when added or applied to food, drug or cosmetic, or to the human body, or any part thereof, is capable, alone or through the reaction with other substance, of imparting color thereto.” Color, for the purposes of this definition, includes black, white and shades of gray. FDA’s regulations state that a color additive includes an ingredient used in animal feed that is intended to impart color to the meat, milk or eggs of the animal. For example, the use of astaxanthin in feed for farm-raised salmon to impart a pink/orange color to their flesh is regulated as a color additive. Some exemptions to the definition of a color additive are provided by the regulations. A substance used to color a container for packaging food, drugs or cosmetics is not a color additive unless the customary use of the container is reasonably expected to result in transmittal of the color to the contents of the container. If such transfer to food does not occur, these substances are regulated as colorants for use in paper or polymers. In addition, food ingredients that are foods themselves such as cherries or green peppers that impart their own natural color are not considered color additives. However, juice extracted from a fruit or vegetable to color foods meets the definition of a color additive, such as beet juice used to make pink lemonade.
Some may wonder why color additives are used at all. Color additives are used to affect or offset color loss, or to correct natural variations in color. They are used to enhance colors that naturally occur but are less intense than those levels usually associated with a given product. Color additives may correspond to flavors, such as in candy, and are often used to decorate foods such as cakes and frostings. An important use of color additives is to provide unique identities to products such as drugs so they are easily distinguishable. Unlike other additives that have a functional effect, color additives are usually used at low concentrations and the amount used is generally self-limiting in that the maximum use level is limited to the color intensity that is desired. For that reason, many color additive regulations require that the amount used should be consistent with Current Good Manufacturing Practices (CGMPs) rather than a specified upper limit.
According to Section 721 of the FD&C Act, a color additive is unsafe unless there is an authorizing regulation or exemption. The use of an unsafe color additive in food makes the food adulterated under Section 402(c) of the FD&C Act. Likewise, cosmetics, drugs and devices with unsafe color additives are deemed adulterated under other parts of the act. It is important to note that one distinction between the statutory definitions of “food additive” and “color additive” is that, unlike the definition for “food additive,” the definition of “color additive” does not have an exclusion for substances that are generally recognized as safe (GRAS) under the intended conditions of use. That is, there is no GRAS exemption for color additives.
Color Additive Regulations
The 1960 Color Additive Amendments created a premarket petition process for approving new color additives or amending an existing color additive regulation. Any interested person may petition FDA for the use of a proposed color additive. Supporting data must be provided as part of the petition. Importantly, it is the petitioner’s responsibility to demonstrate safety of any proposed use of a color additive. If, upon evaluation of the data in the petition, FDA finds that the proposed color additive is safe and suitable for the intended use, the agency will issue a new color additive regulation or alter an existing one. These decisions are announced in the Federal Register.
The color additive regulations are divided into two categories—the approved color additives exempt from batch certification, which are listed in 21 C.F.R. Part 73, and those subject to batch certification, which are listed in 21 C.F.R. Part 74. Most color additive lakes are listed in Part 82 and are required to be certified. The color additives exempt from certification tend to be substances derived from plant, mineral or animal sources, whereas the color additives subject to certification are typically synthetic organic dyes and pigments. The criteria that FDA considers when deciding whether to list a color additive as exempt or subject to certification are discussed later in this article.
The color additive listing regulations generally follow a format consisting of the identity of the color additive, a description of the permitted uses and restrictions, purity specifications and labeling requirements. It is important for a manufacturer to make sure that each color additive in a product is permitted for the intended use and complies with all the requirements in the applicable regulation. For example, FD&C Blue No. 2 is not permitted for use in cosmetics, and FD&C Red No. 4 may be used only in externally applied drugs and cosmetics.