2930.90.92.25 - Other compounds containing a phosphorus atom to which is bonded one methyl, ethyl, n-propyl or isopropyl group, but no other carbon atoms

This HTS classification, 2930.90.92.25, pertains to specific organophosphorus compounds characterized by the presence of a phosphorus atom directly bonded to one methyl, ethyl, n-propyl, or isopropyl group, and importantly, no other carbon atoms. This precise structural requirement distinguishes these compounds from other organophosphorus substances that might have multiple alkyl groups attached to the phosphorus or other carbon-containing moieties. The focus here is on a very particular and limited structure.

Unlike sibling categories such as O,O-Diethyl S-[2-(diethylamino)- ethyl] phosphorothioate or Cysteine hydrochloride, which involve sulfur-phosphorus bonds or amino acids, or N,N-Dialkyl (methyl, ethyl, n-propyl or isopropyl) aminoethane-2-thiols, which clearly contain amine and thiol functionalities, this category is defined by the exclusive presence of a single, simple alkyl group (methyl, ethyl, n-propyl, or isopropyl) directly linked to the phosphorus atom, without any additional carbon chains attached to the phosphorus.

As this is a leaf node within the HTS classification system, there are no further subdivisions. Therefore, the classification process for this code relies solely on confirming the precise chemical structure: the presence of a phosphorus atom bonded to one of the specified small alkyl groups and the absence of any other carbon atoms directly bonded to that phosphorus atom. Examples within this category would be limited to compounds that strictly adhere to this structural definition.