2818 - Artificial corundum, whether or not chemically defined; aluminum oxide; aluminum hydroxide:

Harmonized Tariff Schedule code 2818 encompasses artificial corundum, whether or not chemically defined, as well as aluminum oxide and aluminum hydroxide. These are inorganic chemical compounds primarily derived from aluminum. Artificial corundum, a synthetic form of aluminum oxide, is known for its hardness and is often used as an abrasive or in refractories. Aluminum oxide and aluminum hydroxide, in their various forms, find widespread industrial applications, including in the production of ceramics, catalysts, and flame retardants.

Distinguishing HTS 2818 from its sibling categories, such as live animals (Chapters 01) or live plants (Chapter 06), is straightforward due to the fundamental difference in product type. Chapter 28, to which 2818 belongs, exclusively deals with inorganic chemicals. Therefore, any product falling under 2818 will be a manufactured chemical compound, distinct from raw agricultural products.

Within HTS 2818, further subdivisions clarify specific types of aluminum-based compounds. The subcategory 2818.10 specifically addresses artificial corundum, separating it from other forms of aluminum oxide. Subcategory 2818.20.00.00 covers general aluminum oxide that is not classified as artificial corundum, while 2818.30.00.00 is reserved for aluminum hydroxide. This hierarchical structure allows for precise classification based on the specific chemical composition and form of the aluminum-containing product.