"有机磷酸酯的" can be translated as "organophosphate (related)" or "of organophosphates" in English, depending on the context.
If you're referring to something that is related to or characteristic of organophosphates, you might say "organophosphate-related" or simply "organophosphate" when used as an adjective in a specific context (though the latter is more commonly a noun).
If you're describing a property or characteristic of organophosphates, you could say "of organophosphates," as in "the properties of organophosphates" (有机磷酸酯的特性).
For a more precise translation in a given sentence, consider the following examples:
"有机磷酸酯的毒性" can be translated as "the toxicity of organophosphates."
"有机磷酸酯类化合物" can be translated as "organophosphate compounds."
In general, "organophosphate" is the key term here, and its usage as an adjective or in a prepositional phrase will depend on the specific context.