Synthetic Iron Oxide
Iron Oxides and Iron Hydroxides
Iron Oxide Black
INS No. 172(i)
CAS No. 1317-61-9
CI No. 77499
CI Pigment Black 11
Iron Oxide Red
INS No. 172(ii)
CAS No. 1309-37-1
CI No. 77491
CI Pigment Red 101 and 102
Iron Oxide Yellow
INS No. 172(iii)
CAS No. 51274-00-1
CI No. 77492
CI Pigment Yellow 42 and 43
Iron Oxides are naturally occurring pigments, ranging from black, yellow, red and brown in color. However, commercial forms are produced by synthesis. They impart pastel shades as opposed to some of the brighter and clean shades imparted by other colors.
Typical applications include pet foods, confectionery, cosmetics, and pharmaceuticals.
Iron oxides are added to foods and beverages at concentrations up to a maximum permitted level (MPL) as established by the Codex Alimentarius Commission and published in the General Standard of Food Additives (GSFA) (CODEX STAN 192-1995, 2016).The 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)).
Regulatory Approvals/Consumption Limits
US: Allowed for use in sausage casings NTE 0.1 percent (by wt); Hard and soft candy, mints and chewing gum at GMP (21 CFR 73.200).
JECFA: ADI of 0-0.5 mg/kg body weight (1980)
EC: No ADI allocated (EFSA, 2015). Maximum levels of iron oxides and hydroxides have been defined in Annex II to Regulation (EC) No 1333/2008 on food additives, as amended. Currently, iron oxides and hydroxides are authorized food additives in the EU and permitted to be used in foodstuffs at quantum satis (QS), except in entire fresh fruit and vegetables (at 6 mg/kg).
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.
JECFA (1980). Toxicological evaluation of certain food additives. 23rd Report of the Joint FAO/WHO Expert Committee on Food Additives. WHO Food Additive Series No. 14. Available online.
Full safety monograph available to IACM members or upon request.