9902.02.91 - Oxalic acid (ethanedioic acid dihydrate) (CAS No. 6153-56-6) (provided for in subheading 2917.11.00)

This HTS category, 9902.02.91, specifically classifies oxalic acid (ethanedioic acid dihydrate), identified by CAS No. 6153-56-6. It is important to note that while this specific provision exists within Chapter 99 of the Harmonized Tariff Schedule, its primary reference point for classification under the standard HTS structure is subheading 2917.11.00, which covers saturated acyclic dicarboxylic acids, their anhydrides, halides, peroxides, peroxyacids, their halogenated, sulfonated, nitrated or nitrosated derivatives. This means that while this temporary or special provision exists, the underlying classification of oxalic acid falls within the organic chemicals section.

As this is a leaf node within Chapter 99, there are no further subcategories to explore. The purpose of such a specific entry under Chapter 99 is typically to denote a temporary modification, a specific trade agreement provision, or an additional import restriction. Therefore, when classifying oxalic acid, users should be aware of this special provision and cross-reference it with the permanent classification under subheading 2917.11.00 to ensure compliance with all applicable regulations and duties. The presence of this category underscores the dynamic nature of tariff schedules, where temporary measures can overlay the established classification structure.