2853.90.90.90 - Other

This HTS category, 2853.90.90.90, encompasses a broad range of "other" inorganic compounds that do not fit into more specific subheadings within the broader classification of phosphides, other inorganic compounds, liquid and compressed air, and amalgams. It serves as a residual category for inorganic substances that are chemically defined or compounds not otherwise specified in Chapter 28. This includes various inorganic salts, oxides, hydroxides, and other compounds that have not been assigned a more precise tariff classification.

The key distinction for this "Other" subheading lies in its exclusionary nature. It is intended to capture those inorganic compounds that are not specifically enumerated or provided for elsewhere within the parent categories. For instance, it is distinct from sibling category 2853.90.90.10, which specifically covers undoped gallium arsenide wafers, a specialized semiconductor material. Therefore, any inorganic compound that is not a phosphide (excluding ferrophosphorous), nor specifically listed as distilled or conductivity water, liquid air, compressed air, or an amalgam (other than of precious metals), and also not a gallium arsenide wafer, would likely fall under this residual classification.

As this is a terminal node within the HTS structure, there are no further subcategories for this particular code. Classification into 2853.90.90.90 relies on a thorough review of the chemical composition and the absence of any more specific tariff classification for the imported or exported inorganic compound. Importers and exporters should meticulously examine the full nomenclature and explanatory notes of Chapter 28 to ensure proper classification and avoid potential customs issues.