2930.90.43.10 - O-Ethyl-S-phenylethylphosphono- thiolothionate (fonofos)

This classification covers O-Ethyl-S-phenylethylphosphonothiolothionate, also known by its ISO name, fonofos. Fonofos is an organothiophosphate insecticide that functions as a cholinesterase inhibitor. Its specific chemical structure, featuring an O-ethyl and S-phenylethyl group attached to a phosphonothiolothionate core, distinguishes it within the broader category of organo-sulfur compounds. This classification is relevant for goods imported or exported for use in agricultural or pest control applications.

When classifying within this specific sub-level (2930.90.43.10), it is crucial to differentiate fonofos from its siblings. For instance, phorate (2930.90.43.15) and terbufos (2930.90.43.30) are other organothiophosphate insecticides with distinct chemical structures and applications, necessitating their separate classification. Similarly, the category for compounds containing a single methyl, ethyl, n-propyl, or isopropyl group bonded to phosphorus (2930.90.43.20) covers a different subset of organophosphorus compounds and does not encompass the more complex structure of fonofos. The "Other" category (2930.90.43.90) serves as a residual classification for organo-sulfur pesticides not otherwise specified.

As this is a leaf node within the HTS, there are no further subcategories. Classification at this level is based on the precise identification of O-Ethyl-S-phenylethylphosphonothiolothionate (fonofos) through its chemical name and structure. The primary classification criterion is the presence of this specific active ingredient, identifying the product as a formulated or unformulated pesticide of the organothiophosphate class.