2922.21.50.00 - Other

This HTS category, 2922.21.50.00, covers "Other" aminohydroxynaphthalenesulfonic acids and their salts, excluding those specifically described in other subheadings. These compounds are characterized by the presence of both an amino group (-NH2), a hydroxyl group (-OH), and a sulfonic acid group (-SO3H) attached to a naphthalene ring system. The classification of a product within this subheading depends on its specific chemical structure and the absence of any other oxygen-containing functional groups beyond those typically found in phenols or naphthols, and their corresponding ethers and esters, which are addressed in the preceding parent categories.

The key distinction for this "Other" category lies in its residual nature. It encompasses aminohydroxynaphthalenesulfonic acids and their salts that do not fit into more specific classifications within the 2922.21.40.00 subheading, which is designated for products defined by additional U.S. notes pertinent to Section VI. Therefore, when classifying a compound under this heading, it is crucial to first determine if it meets the criteria for any more precisely defined subcategories.

As this is a leaf node in the HTS database, there are no further subdivisions under 2922.21.50.00. Classification within this category relies on ensuring the compound is an aminohydroxynaphthalenesulfonic acid or its salt and that it does not qualify for any other specific provisions within the broader aminohydroxynaphthalene classification. Examples might include specific isomers or derivatives not otherwise enumerated.