An artificial food dye, or “color additive” is defined by the FDA as “any dye, pigment or substance which when added or applied to a food, drug or cosmetic, or to the human body, is capable (alone or through reactions with other substances) of imparting color.” They are often made from petroleum and used to enhance existing color, add new color to colorless foods or correct any loss of color that occurs during storage, processing or use of a product.
From the FDA:
Certified colors are synthetically produced (or human made) and used widely because they impart an intense, uniform color, are less expensive, and blend more easily to create a variety of hues. There are nine certified color additives approved for use in the United States (e.g., FD&C Yellow No. 6. See [below] for a complete list). Certified food colors generally do not add undesirable flavors to foods.
The seven standard artificial food dyes used in the United States, also known as “Certified Colors” are:
FD&C Blue #1 (Brilliant Blue, E133),
FD&C Blue #2 (Indigotine, E132),
FD&C Green #3 (Fast Green FCF, E143),
FD&C Red #3 (Erythrosine, E127),
FD&C Red #40 (Allura Red AC, E129),
FD&C Yellow #5 (Tartrazine, E102), and
FD&C Yellow #6 (Sunset Yellow FCF, E110).
There are two other artificial colorings used in the United States, but with limits: FD&C Orange B is only permitted for use in hot dog and sausage casings. FD&C Red Citrus #2 is only permitted for coloring the skin of oranges. It is worth noting that the IARC (International Agency for Research on Cancer) has listed FD&C Red Citrus #2 as a Group 2B Carcinogen, or possibly carcinogenic to humans.
At Foodfacts.com, we have two major points of concern when it comes to artificial dyes.
The first is the disputed safety of these dyes, as studies have linked them to causing cancer in lab animals, hyperactivity in children with ADHD and more. In 1984, the FDA’s Acting Commissioner, Mark Novitch, said that Red #3 was “of greatest public health concern…The agency should not knowingly allow continued exposure [to a] color additive that has clearly been shown to induce cancer while questions of mechanism are explored.” Unfortunately, the FDA only banned the use of Red #3 in cosmetics and certain drugs, as well as the “lake” version of this dye.  CSPI, the Center for Science in the Public Interest, has summarized the studies available for Food Dyes in this chart: Click here. There is still significant need for more independent study and analysis.
Our second concern is the way food coloring affects the psychological aspect of eating. Bright food coloring is often used in processed or “junk” foods, which are also full of sugar, fat and other controversial ingredients. Because things like candy and snacks are usually colored in fun and bright ways, children are drawn to them rather than more nutritious food. This trains kids to think that “bright” is delicious, forming a habit that points them towards snack food rather than a healthier option.