2920.19.10.00 - O,O-Dimethyl-O-(4-nitro-m-tolyl)phosphoro- thioate (Fenitrothion)

This HTS subheading specifically classifies organophosphate insecticides of the thiophosphoric ester type, characterized by their aromatic structure. The primary example within this category is Fenitrothion (O,O-Dimethyl-O-(4-nitro-m-tolyl)phosphorothioate), a widely used insecticide. The classification hinges on the chemical structure, specifically the presence of thiophosphoric ester groups and an aromatic moiety, often modified by halogenation, sulfonation, nitration, or nitrosation, for enhanced pesticidal properties.

While this category and its sibling, 2920.19.40.00 "Other," both fall under "Thiophosphoric esters (phosphorodithioates) and their salts, their halogenated, sulfonated, nitrated or nitrosated derivatives," the distinction lies in the aromatic nature of the compound. Subheading 2920.19.10.00 is reserved for aromatic thiophosphoric esters, whereas the "Other" subheading would encompass aliphatic or cycloaliphatic derivatives, or other compounds that do not meet the aromatic criteria.

As this is a leaf node within the HTS, there are no further subcategories. Classification under this specific code is determined by the precise chemical identity of the product, confirming it to be an aromatic thiophosphoric ester derivative, such as Fenitrothion, and ensuring it is not more specifically classified elsewhere. The emphasis is on the confirmed presence of the defined chemical structure and its functional properties as an insecticide.