2915.60 - Butanoic acids, pentanoic acids, their salts and esters:

This HTS category, 2915.60, encompasses butanoic acids (also known as butyric acids), pentanoic acids (also known as valeric acids), and their corresponding salts and esters. These are saturated acyclic monocarboxylic acids with four and five carbon atoms in their chain, respectively, along with derivatives where the carboxyl group is functionalized as a salt or ester. Examples include butanoic acid itself, its sodium salt, ethyl butanoate, pentanoic acid, and methyl pentanoate.

Category 2915.60 is distinguished from its sibling categories by the specific carbon chain length of the carboxylic acid. While sibling categories cover shorter chain acids like formic (2915.11), acetic (2915.20), propionic (2915.50), and chlorinated acetic acids (2915.40), this category focuses on acids with four or five carbon atoms. It also differs from categories that might cover longer chain fatty acids or unsaturated carboxylic acids, which fall under different HTS provisions.

The subcategories within 2915.60 are based on the structural nature of the acid or its derivative. The primary distinction is between "Aromatic" and "Other." The "Aromatic" designation likely applies to butanoic or pentanoic acid derivatives where an aromatic ring is present, even if the carboxylic acid group itself is part of an aliphatic chain. The "Other" subcategory covers all remaining butanoic and pentanoic acids, their salts, and esters that do not meet the criteria for aromatic classification, thus encompassing the vast majority of these specific aliphatic carboxylic acid derivatives.