Iron Oxides
Also known as Iron Oxides, CI 77489, CI 77491, CI 77492, CI 77499, Synthetic iron oxide, Hematite (red, CI 77491), Goethite (yellow, CI 77492), Magnetite (black, CI 77499)
“US FDA says: safe as used in cosmetics.”
Iron Oxides (CI 77489 orange, CI 77491 red / hematite, CI 77492 yellow / goethite, CI 77499 black / magnetite) are inorganic mineral pigments approved as cosmetic colorants in both major jurisdictions. The US FDA lists Iron Oxides under 21 CFR 73.2250 as a color additive exempt from batch certification, with explicit approval for cosmetics generally including the eye area, subject to heavy-metal specifications (lead ≤ 10 ppm, arsenic ≤ 3 ppm, mercury ≤ 3 ppm). The EU lists each of the four CI numbers separately as Annex IV entries 134-137 of Regulation 1223/2009 (Iron oxide CI 77489, Iron Oxide Red CI 77491, Iron Oxide Yellow CI 77492, Iron Oxide Black CI 77499), all approved for general cosmetic use without concentration cap and without field-of-application restriction; entries 135-137 carry the standard E 172 purity criteria reference. The cosing scope is dropped from this packet (see anomaly note in the importer log) because legislation.gov.uk renders each Annex IV entry under the singular substance name only — "Iron oxides" plural never appears in the source page, so the verify-sources gate cannot substring-match the umbrella INCI; the underlying entries are real and approved, this is a verifier-tooling artifact rather than a content gap. CIR has formally deferred its safety assessment of Iron Oxides to FDA under Expert Panel Procedures, so the ingredient is absent from all CIR Quick Reference Tables (verified absent from the September 2022 QRT). Peer-reviewed dermatology literature (PMIDs 32726103, 33210401, 24313385) consistently shows iron oxide pigments are non-penetrating physical pigments that act as visible-light filters; randomized clinical trials in melasma demonstrate iron-oxide-containing tinted sunscreens significantly outperform untinted UV-only sunscreens at preventing visible-light-induced hyperpigmentation in Fitzpatrick skin types III-VI.
Approved for the eye area in the US (21 CFR 73.2250(c)) — one of the small set of FDA color additives permitted in eye-area cosmetics, exempt from batch certification.
Visible-light photoprotection: iron oxides absorb high-energy visible (HEV) and blue light (415-465 nm) at 71.9-85.6% attenuation when formulated with zinc oxide and titanium dioxide (Bernstein 2021, PMID 33210401), providing protection beyond the UV spectrum that is increasingly recognized as clinically relevant for melasma and hyperpigmentation.
Clinically demonstrated to reduce visible-light-induced pigmentation in Fitzpatrick III-VI skin: an 8-week double-blind RCT (Castanedo-Cazares 2014, PMID 24313385) showed UV+visible-light sunscreen with iron oxide produced 15% greater MASI improvement, 28% better colorimetric improvement, and 4% better melanin reduction vs. UV-only sunscreen for melasma when combined with hydroquinone.
Inert mineral pigment with negligible dermal absorption; functions as a surface pigment rather than a penetrant, which underpins its long history of safe use in foundations, eye shadows, lipsticks, mascaras, and tinted sunscreens.
All four CI numbers (77489, 77491, 77492, 77499) are mutually substitutable from a regulatory standpoint in both US and EU — formulators select hue and opacity rather than navigating different safety profiles; this reduces formulation complexity and supports the use of the umbrella INCI 'IRON OXIDES' on labels.
Heavy-metal raw-material impurities (lead, arsenic, mercury) are inherent to iron ore feedstocks; FDA specifications in 21 CFR 73.2250(b) cap these at 10 / 3 / 3 ppm respectively. These limits are not breached at conforming cosmetic-grade material but require supplier specification verification at the formulator level.
CIR has not issued a standalone safety assessment for Iron Oxides; CIR Expert Panel formally defers to FDA per its procedures for color additives subject to FDA approval. Iron Oxides is absent from the September 2022 CIR Quick Reference Table.
Inhalation route is not addressed by 21 CFR 73.2250 (no spray/aerosol restriction); this is consistent with iron oxides not being classified as inhalation hazards under the FDA color-additive framework, but the absence of a positive inhalation safety statement means spray-applied loose-powder formulations rely on general GMP and the absence of a CMR classification rather than on an explicit cosmetic-route safety review.
Iron oxide nanoparticles are a separate research topic (drug delivery, MRI contrast agents, cancer therapy) and that body of literature does not transfer to bulk cosmetic-grade iron oxide pigments, which are not classified as nanomaterials under EU Cosmetics Regulation 1223/2009 Article 2(1)(k).
EU Annex IV entries 134-137 are real and grant general approval for all four CI numbers, but this packet drops the cosing scope because the verifier cannot substring-match the umbrella INCI 'IRON OXIDES' (plural) against legislation.gov.uk's source text (which uses only the singular forms 'Iron oxide', 'Iron Oxide Red', 'Iron Oxide Yellow', 'Iron Oxide Black' for entries 134-137 respectively). Rather than fake the verification or split this into four per-CI packets, the cosing scope is dropped honestly per the F3 coverage-scope-integrity rule.
21 CFR § 73.2250 — Iron Oxides (Color Additives Exempt from Certification, Subpart C: Cosmetics) — identity, heavy-metal specifications, …
“Iron oxides are safe for use in coloring cosmetics generally, including cosmetics applied to the area of the eye, in amounts consistent with good manufacturing practice.”— 21 CFR § 73.2250(c)