FD&C Yellow No. 5, the food dye also known by the chemical name tartrazine, does not contain pork or any other animal products. It is a completely synthetic organic chemical.
Tartrazine is defined by chemists as a synthetic lemon yellow azo dye. While considered generally safe by the U.S. Food and Drug Administration, there have been infrequent but documented cases of tartrazine sensitivity, according to a study published in American Family Physician. For this reason, food manufacturers are required to note its use on food and drug ingredient labels. Symptoms of tartrazine sensitivity include vasculitis (inflammation of the blood vessels), purpura (red or purple skin discolorations) and contact dermatitis (skin inflammation caused by direct contact with a substance).