Iron oxide red

Iron oxide red (CAS 1309-37-1), also sold as C.I. Pigment Red 101, red oxide, and approved as food colorant E172(ii), is a synthetic or naturally derived inorganic pigment. It is used to impart color and corrosion resistance across a broad range of industrial and consumer applications. Its high UV stability and opacity make it a preferred colorant where long-term color retention under outdoor exposure is a commercial requirement. In architectural and industrial coatings, red iron oxide provides both color and a passive barrier against substrate corrosion.

This pigment reduces coating system failures in marine and infrastructure environments. Concrete, paving blocks, and fiber cement products use it as a mass-toning pigment to achieve consistent, fade-resistant earth tones at scale. Automotive OEM and refinish primers rely on its corrosion-inhibiting properties as a functional component, not just a colorant. Printing inks and packaging coatings for construction materials also incorporate it where heat-stable, non-bleeding color is required.

Iron oxide red is supplied as a dry powder in both synthetic and natural grades, with synthetic grades offering tighter particle size distribution and higher tinting strength. Standard grades include technical, construction-grade, and cosmetic/food-grade material. Synthetic grades are also available to meet ASTM D3722 and ISO 11553 standards relevant to pigment performance benchmarking. These materials ensure high quality and consistency for demanding industrial manufacturing processes.