2918.91.00.00 - 2,4,5-T (ISO) (2,4,5-trichlorophenoxyacetic acid), its salts and esters

This HTS category, 2918.91.00.00, specifically classifies 2,4,5-T (2,4,5-trichlorophenoxyacetic acid), along with its corresponding salts and esters. This compound is a synthetic auxin, historically used as a herbicide, and is a derivative of acetic acid with a significant oxygen functional group, falling under the broader heading for carboxylic acids with additional oxygen function. Its precise chemical structure and intended application as a specific chemical compound are key to its distinct classification.

This classification is distinguished from its sibling category, 2918.99, which covers all other "Other" carboxylic acids with additional oxygen function and their derivatives not specifically enumerated elsewhere. While both fall under the "Other" designation within their parent heading, 2918.91.00.00 is reserved for the highly specific compound 2,4,5-T and its direct derivatives. The sibling category acts as a residual classification for less specifically defined or less commonly encountered substances within this broader chemical family.

As this is a leaf node within the HTS structure, there are no further subcategories. Therefore, classification under 2918.91.00.00 is definitive for the described substance and its salts or esters. The emphasis for classification professionals lies in correctly identifying the chemical entity as 2,4,5-T or one of its specified salts or esters, ensuring it is not misclassified under a more general "Other" category or a different chemical heading altogether.