3824.99.93.61 - Mixtures consisting mainly of chemicals containing a phosphorus atom to which is bonded one methyl, ethyl, n-propyl or isopropyl group, but no other carbon atoms

This HTS subcategory, 3824.99.93.61, encompasses specific chemical mixtures characterized by the presence of a phosphorus atom directly bonded to a methyl, ethyl, n-propyl, or isopropyl group. Crucially, these mixtures must not contain any other carbon atoms beyond those in the specified alkyl groups. This precise chemical structure is the defining characteristic for classification under this heading, differentiating it from broader chemical mixtures.

Distinguishing this category from its siblings, 3824.99.93.61 focuses on the molecular structure of organophosphorus compounds. It is distinct from sibling category 3824.99.93.86, which covers mixtures containing magnesium used for desulfurization, highlighting a functional rather than a structural criterion. The other sibling, 3824.99.93.97 ("Other"), would capture any remaining mixtures within the parent heading that do not meet the specific chemical requirements of 3824.99.93.61 or the functional criteria of 3824.99.93.86.

As this is a leaf node in the HTS classification structure, there are no further subcategories. Therefore, the classification of goods under 3824.99.93.61 relies solely on meeting the stated chemical composition criteria. Examples of products that would fall here include certain flame retardants, plasticizers, or intermediates in organic synthesis where the specified organophosphorus structure is present and no other carbon atoms are attached to the phosphorus.