2918.22 - O-Acetylsalicylic acid, its salts and esters:

This HTS category, 2918.22, encompasses O-acetylsalicylic acid, commonly known as aspirin, along with its corresponding salts and esters. These compounds are characterized by the presence of a carboxyl group (-COOH) and a phenolic hydroxyl group on the same molecule, with the phenolic hydroxyl group specifically acetylated. This distinct chemical structure differentiates them from other salicylic acid derivatives.

Distinguishing this heading from its siblings, 2918.21 covers salicylic acid itself and its simple salts. Heading 2918.23 focuses on other esters of salicylic acid that are not O-acetylated, and their salts. Therefore, 2918.22 is specifically reserved for the acetylated derivative of salicylic acid and its derived salts and esters, highlighting the particular acetylation of the phenolic group.

The subcategories under 2918.22 further refine the classification based on the specific form of the O-acetylsalicylic acid. 2918.22.10.00 isolates pure O-acetylsalicylic acid (Aspirin) for classification, while 2918.22.50.00 is designated for salts and esters derived from O-acetylsalicylic acid, such as sodium acetylsalicylate or various esterification products. This breakdown ensures precise tariff application based on the precise chemical entity being imported or exported.