2931.90.90.21 - Dibutyltin oxide 🖩

This HTS classification covers dibutyltin oxide, a specific organo-tin compound. Organo-tin compounds are characterized by the presence of at least one tin-carbon bond. Dibutyltin oxide is a derivative of tin where butyl groups are directly bonded to the tin atom, and oxygen bridges the tin atoms in its oxide form. It is typically used as a stabilizer in plastics, particularly PVC, and as a catalyst in various chemical reactions, including the production of polyurethanes and silicones.

Distinguishing this classification from its siblings, 2931.90.90.25 (Tetrabutyltin) and 2931.90.90.29 (Other organo-tin compounds), is crucial for accurate reporting. Tetrabutyltin has four butyl groups directly bonded to a single tin atom. Dibutyltin oxide, in contrast, features two butyl groups attached to tin and exists in an oxide form, often as a dimer or polymer. The "Other" category (2931.90.90.29) is a residual category for organo-tin compounds not specifically listed, making dibutyltin oxide's unique chemical structure the basis for its distinct classification.

As a leaf node, this classification does not have further subcategories. Therefore, the primary focus for classification professionals is on identifying the precise chemical identity of the imported substance. Confirmation of the substance as dibutyltin oxide, based on its chemical formula, physical properties, and intended use as indicated by supporting documentation, is paramount to correctly applying this HTS code.