2915.50 - Propionic acid, its salts and esters:

This category, HTS 2915.50, specifically encompasses propionic acid, along with its various salts and esters. Propionic acid is a saturated monocarboxylic acid, commonly found as a liquid with a pungent odor, and is widely used as a preservative in food products, particularly animal feed, and as a precursor in the synthesis of various chemicals. Salts of propionic acid, such as sodium propionate and calcium propionate, are also included, as are its esters, which are formed by reacting propionic acid with alcohols.

Distinguishing this group from its siblings, this heading focuses solely on compounds derived from propionic acid. For instance, it is separate from the formic acid, acetic acid, and chloroacetic acid categories, which cover acids with fewer carbon atoms or halogenated derivatives. It also differs from the butanoic and pentanoic acid categories (2915.60), which deal with saturated monocarboxylic acids containing a greater number of carbon atoms. The scope here is precisely limited to the three-carbon carboxylic acid and its direct derivatives.

Within this classification, HTS 2915.50.10.00 is dedicated to propionic acid itself. The "Other" subcategory is reserved for the salts and esters of propionic acid, allowing for a clear distinction between the free acid and its derivative compounds for specific tariff purposes. This subdivision facilitates accurate customs declarations based on the precise chemical form being imported or exported.