Iron oxides and hydroxides

Iron oxides and hydroxides are inorganic mineral pigments that occur naturally in soil and rock. As food additives (E172), they are produced synthetically to achieve the required purity and are available in yellow (E172i), red (E172ii), and black (E172iii) forms, allowing a range of earthy colours from cream through orange, red, and brown. In food, they are used on the surfaces of confectionery, sugar-panned sweets, cheese rinds, and decorative cake products, as well as in salmon and pet food.

JECFA evaluated iron oxides and hydroxides in 1969 and did not establish a numerical ADI, classifying them as not specified. Iron is an essential dietary mineral and iron oxides are chemically stable, poorly soluble compounds that are not significantly absorbed from the gastrointestinal tract at the quantities used as colourants.

Iron oxides are approved globally, including in the EU (E172), the United States, and most other markets. Their use in food is generally restricted to surface applications or very specific food categories. They are among the oldest pigments used by humans and are considered safe across all population groups at typical food-use levels. Consumers with hereditary haemochromatosis who need to restrict dietary iron should note that products using iron oxides as colourants contribute negligibly to iron intake given the insoluble nature of the compounds.