Iron Oxides
The short version
Mineral pigments providing red, yellow, and black tones — increasingly used as a natural replacement for titanium dioxide.
It's widely considered safe at the amounts used in food, so we mark it green. The Safety section below has the details.
Where it comes from
Naturally occurring iron-oxide minerals refined and purified for food-grade use. Production today is largely from synthetic iron precipitation under controlled conditions to ensure consistent particle size and color.
How it's used
Used to color confectionery, cake decorations, sausage casings, pet food, and tablet coatings. Gained prominence as a natural opacifier and tone-modifier after the EU banned titanium dioxide (E171) in food in 2022.
Safety profile
ADI of 0.5 mg/kg body weight expressed as iron (JECFA). Iron is an essential nutrient at low levels; the additive use contributes a small fraction of dietary iron compared to fortified flours. Considered safe at typical use levels.
Physical & chemical properties
Powdered pigments ranging from yellow-orange (FeOOH), through red (Fe2O3), to black (Fe3O4). Insoluble in water and most solvents. Excellent stability to light and heat.
Regulation worldwide
Permitted globally. Food-grade purity specifications limit heavy-metal impurities.
Educational information only. Not medical or dietary advice.