E121 - Citrus Red 2

Citrus Red 2, Citrus Red No. 2, C.I. Solvent Red 80, or C.I. 12156 is an artificial dye. As a food dye, it has been permitted by the US Food and Drug Administration (FDA) since 1956 to color the skin of oranges. Citrus Red 2 is listed by the International Agency for Research on Cancer (IARC) as a group 2B carcinogen, a substance "possibly carcinogenic to humans".