2917.13.00.90 - Other

This HTS category, 2917.13.00.90, encompasses "other" acyclic polycarboxylic acids, their salts, and esters that are not specifically listed under the preceding tariff lines. This classification serves as a residual category for such compounds when they do not fit the more defined descriptions of sebacic acid (2917.13.00.30) or azelaic acid, which is implicitly covered within this broader grouping. These substances are characterized by having two or more carboxyl groups (-COOH) attached to an open chain of carbon atoms, differentiating them from cyclic or aromatic polycarboxylic acids found in other HTS chapters.

To properly classify goods under this heading, one must first ensure they are acyclic polycarboxylic acids, their salts, or esters. The distinction from the sibling category 2917.13.00.30 is crucial; this specific heading is reserved for sebacic acid and its direct derivatives. If a substance is not sebacic acid, and it fits the broader definition of acyclic polycarboxylic acids, its derivatives, salts, or esters, then it would likely fall under this residual "Other" category, provided no other more specific HTS provision applies.

As this is a leaf node in the HTS structure, there are no further subcategories to introduce. Therefore, classification within 2917.13.00.90 relies heavily on the precise chemical structure of the compound and its confirmation that it is an acyclic polycarboxylic acid, its salt, or ester, and not otherwise specified. This ensures that all relevant compounds within this chemical family are accounted for within the tariff schedule.