The ingredient, explained

Ci 77491

A published expert safety assessment covers the exact ingredient in the specified exposure context.

Cosmetic colorant

Explore connections

Ingredient guide

What it is and what it does

Diiron trioxide; Ferric oxide

About this ingredient: EU CosIng ingredient registry (via Open Beauty Facts taxonomy) ↗

Cosmetic colorant: Adds colour to a product or the surface where it is applied.

Function definitions: European Commission ingredient function definitions (SCCNFP/0299/00, pages 16 to 20) ↗

Registry functions describe possible formulation roles, not results for a finished product. A dictionary entry is not an approval or a safety assessment.

A closer look

What the research shows

Safety assessment

EFSA could not complete an adequate safety assessment because of insufficient toxicology and unresolved genotoxicity, including red iron oxide data.

What this does not tell us

Food additive oral assessment, not cosmetic efficacy or a blanket unsafe finding for dermal use. Redox state, particle size, grades and impurities prevent transfer between oxides. Other input CAS entries were not resolved.

Sources for this summary. DOI 10.2903/j.efsa.2015.4317 ↗

Research review checked Oct 1, 2026

Bounded review of local candidates, exact-name indexed primary journal/PubMed safety and topical searches; not a systematic review.

Ingredient research is not proof that a product containing this ingredient works.