INS No. 172(i); Iron oxide, black
INS No. 172(ii); Iron oxide, red
INS No. 172(iii); Iron oxide, yellow
Synthetic iron oxide
E 172; Iron oxides and hydroxides
Synthetic iron oxide consists of any one or any combination of synthetically prepared iron oxides, including the hydrated forms. Iron oxides are produced from ferrous sulfate by heat soaking, removal of water, decomposition, washing, filtration, drying, and grinding. They are produced in either anhydrous or hydrated forms. The range of hues for synthetic iron oxide includes yellows, reds, browns and blacks.
Typical applications include cosmetics, and pharmaceuticals, and foods, including confectionery, cereals, edible ices, sausage casings, dietary supplements, flavored milk and water based drinks, soups and broths, and fruit preparations.
Iron oxides (INS Nos. 172(i-iii)) are added to foods and beverages at concentrations up to maximum permitted levels (MPLs) as established by the Codex Alimentarius Commission and adopted in the General Standard of Food Additives (GSFA). The 32 provisions are defined at the additive group level, and thus apply to the total content of the additives participating in this group: Iron oxide, black (172(i)); Iron oxide, red (172(ii)); and Iron oxide, yellow (172 (iii)).
Evaluation of certain food additives (23rd Report of the Joint FAO/WHO Expert Committee on Food Additives) WHO Technical Report Series No 648, 1980. Available online
Listing of Color Additives Exempt from Certification; Synthetic Iron Oxide, 83 FR 54869 (Nov 1, 2018). Available online
Listing of Color Additives Exempt from Certification; Synthetic Iron Oxide, 80 FR 14839 (Mar 20, 2015). Available online
ANS Panel (EFSA Panel on Food Additives and Nutrient Sources added to Food), 2015. Scientific Opinion on the re-evaluation of iron oxides and hydroxides (E 172) as food additives. EFSA Journal 2015;13(12):4317, 57 pp. Available online