2915.40 - Mono-, di- or trichloroacetic acids, their salts and esters:

This category encompasses mono-, di-, and trichloroacetic acids, along with their corresponding salts and esters. These are organic compounds characterized by the presence of chlorine atoms substituted onto an acetic acid molecule. Examples include monochloroacetic acid (MCA), dichloroacetic acid (DCA), and trichloroacetic acid (TCA), as well as their sodium, potassium, or other salt forms, and various ester derivatives. These compounds find application in a range of industrial processes, including the production of herbicides, pharmaceuticals, dyes, and as chemical intermediates.

Distinguishing this category from its siblings, such as those for formic acid, acetic acid, propionic acid, or butanoic acids, lies in the specific halogenation of the acetic acid structure. While siblings cover saturated acyclic monocarboxylic acids and their derivatives without halogen substitution at the position relevant to this grouping, this classification is exclusively for those where chlorine atoms are present on the acetic acid moiety. The presence and number of chlorine atoms are key identifiers for classification within this group.

The subcategories here further refine the classification based on the specific form of the chlorinated acetic acid. "Chloroacetic acids" specifically covers the acid forms themselves, while the "Other" category would encompass their salts and esters. This subdivision allows for precise identification and duty assessment based on whether the product is the pure acid or a derivative thereof.