2821 - Iron oxides and hydroxides; earth colors containing 70 percent or more by weight of combined iron evaluated as Fe2O3:

Heading 2821 encompasses iron oxides and hydroxides, along with earth colors where the combined iron content, evaluated as Fe2O3, constitutes 70 percent or more by weight. These materials are primarily inorganic chemical compounds of iron, characterized by their color and opacity. They find widespread use as pigments in paints, coatings, plastics, inks, and construction materials.

Unlike sibling categories within Section VI, which cover a broad spectrum of chemical products from live animals to live poultry (Chapter 01), Heading 2821 specifically isolates iron-based inorganic compounds used for their coloring properties. It is crucial to differentiate these iron oxides and hydroxides from other iron compounds or minerals not meeting the specified iron content threshold or not primarily utilized for their pigmentary characteristics.

Within Heading 2821, two primary subheadings exist: 2821.10, for iron oxides and hydroxides themselves, and 2821.20, for earth colors. This distinction allows for more granular classification based on whether the material is a pure iron oxide/hydroxide or a naturally occurring mineral earth colored by iron compounds, provided the iron content requirement is met.