A vibrant and energetic color, yellow is a common color used by manufacturers for a wide selection of products such as food, cosmetics, and even medications. One common dye used in the industry to provide such a color is Yellow 5 – an azo dye that exhibits a lemon-yellow color.
Yellow 5 is a synthetic food coloring agent, meaning it is manufactured in a lab without the use of animal products or by-products. Although the dye can be considered vegan from that standpoint, many vegans avoid food color additives such as Yellow 5 because they undergo animal testing. Thus, Yellow 5 can be considered vegan by dietary vegans, but it cannot be considered ethically vegan.
Yellow 5 is a food color additive that industries use to make their products have a lemon-yellow color. A water-soluble dye, Yellow 5 is also known by many other names such as Tartrazine, E102, CI 19140, FD&C Yellow 5, Acid Yellow 23, and Food Yellow 4.
Under a spectrophotometer, Yellow 5 gives an absorbance of 425 nm which appropriately places the dye in the range of the yellow in the color spectrum.
Since Yellow 5 is made without the use of any animal products, Yellow 5 can be considered vegan by dietary vegans. In the lab, Yellow 5 is made of different various chemicals.
Despite the lack of animal products in Yellow 5, a significant portion of the vegan community prefers products that don’t use food coloring agents.
There are two main groups of vegans that avoid products that use synthetic food coloring additives such as Yellow 5: vegans who avoid heavily processed food and vegans who avoid products that have been tested on animals.
Vegans who prefer non-processed or minimally processed products believe that numerous industrial steps in manufacturing take away the nutrition from the raw ingredients. Additionally, purely synthetic products such as a food coloring additive add no nutritional value to food-stuff.
A strong component in the vegan community is the stand against animal cruelty, hence the general abstinence towards animal products. However, this can extend to products that have undergone animal testing as these studies are perceived to be unethical (especially those that discard or kill animals in the process, or at the end of the study).
Yellow 5 is generally considered to be safe by numerous food safety authorities such as the FDA in the US and the EFSA in Europe. With its own set of standards, the US Environmental Protection Agency also deems Yellow 5 to be “verified to be of low concern based on experimental and modeled data (1).”
Furthermore, the FDA supports the safety of Yellow 5 since it is one of the nine certified color additives the agency has allowed to be used for food. Along with Yellow 5, this list includes Blue 1, Blue 2, Green 3, Orange B, Red 2, Red 3, Red 40, and Yellow 6.
Aside from determining what types of food these synthetic food dyes are allowed to be added to, the FDA also regulates how much of the food color additives can be added to each product.
While different food safety authorities have approved the use of Yellow 5 with sufficient evidence for their safety, caution can still be practiced when consuming products containing this food coloring agent. Different reports and studies have shown evidence that Yellow 5 might be potentially dangerous.
Yellow 5 has been found to contain benzidine and other carcinogens. Other studies have also found Yellow 5 to be positive for genotoxicity, the ability of certain chemicals to damage genetic information within the cell (2).
Currently, there are two ways by which Yellow 5 is industrially synthesized (3).
The first method couples diazotized sulfanilic acid with the reaction of the condensation of phenylhydrazine-p-sulfonic acid with oxalacetic ester. The resulting ester from these reactions is then hydrolyzed with sodium hydroxide.
The second method condenses two moles of phenylhydrazine-p-sulfonic acid with a mole of dihydroxytartaric acid.
All synthetic food coloring agents, including Yellow 5, are required to undergo numerous animal testing studies to make sure they are safe for public consumption. Important tests include long-term toxicology and carcinogenicity studies, especially because food coloring agents are typically present in food in minute quantities which means they might not have apparent immediate effects.
Animal testing is believed to be a cruel and unethical practice according to the vegan community, as well as other communities that stand against animal abuse and cruelty.
In the past, using animal models may have been required to conduct such safety assessments, but modern technological advancements have developed other methods that do not require the use of animals such as in vitro assays (i.e., the use of cell models instead of animal models) and in silico studies (i.e., the use of computer models and algorithms).
Being a highly popular color for a myriad of products, Yellow 5 is documented to be used in products such as food, cosmetics, and even medications. In the US alone, three synthetic food dyes make up about 90% of all the FD&C dyes used and Yellow 5 is one of them.
In food, Yellow 5 is used in soft drinks, other beverages, baked goods, breakfast cereals, processed vegetables, chips, pickles, honey, mustard, gelatin desserts, pudding, ready-to-use frostings, dessert powders, candy, other foods, and gum.
Yellow 5 is also extensively used in cosmetics and personal care products such as liquid and bar soaps, hand sanitizers, moisturizers, lotions, mouthwashes, perfumes, toothpaste, shampoos and conditioners, other hair products, eyeshadow, blush, face powder, foundation, lipstick, and nail polish.
Medications also use a great deal of color additives to make them easily identifiable. This means that pharmaceutical companies sometimes add Yellow 5 to their products such as vitamins, antacids, and prescription drugs.
Products that contain Yellow 5 are not necessarily color yellow because the dye is often mixed with other dyes. For example, some manufacturers combine Yellow 5 with blue or green dyes to make different shades of green.