2908.99.15.00 - Other

This HTS subheading, 2908.99.15.00, encompasses "Other" derivatives containing only sulfo groups, their salts, and esters, where these compounds do not fall under any more specific prior subcategories within Chapter 29. This category serves as a residual classification for sulfo-containing phenol derivatives that are not specifically listed or defined elsewhere. Classification here hinges on the absence of other specific functional groups or structural characteristics that would place the compound into a more precisely defined subheading.

It is crucial to distinguish this category from its sibling, 2908.99.12.00. The latter specifically includes products that are described in additional U.S. note 3 to section VI. Therefore, if a sulfo-containing phenol derivative meets the criteria outlined in that specific U.S. note, it would be classified under 2908.99.12.00, rather than this broader "Other" category. This distinction ensures that specific trade policy considerations or unique product definitions are correctly applied.

As this is a leaf node in the HTS structure, there are no further subcategories to introduce. Classification directly into 2908.99.15.00 means the product is fully defined by this subheading. Practical classification will often involve detailed chemical analysis to confirm the presence of only sulfo groups (as sulfonic acids, sulfonates, or sulfonate esters) in combination with a phenol or phenol-alcohol structure, and the absence of any other defining characteristics that would warrant classification in a more specific provision within Chapter 29.