Ethyl O-(p-nitrophenyl) phenyl phosphonothionate
Ethyl O-(p-nitrophenyl) phenyl phosphonothionate is an organic compound with a phosphorous group. It is used as a pesticide. At room temperature it appears as a yellow powder, but at temperatures above 35 °C it becomes a brown liquid.
Ethyl O-(p-nitrophenyl) phenyl phosphonothionate has been used as an insecticide on a variety of plants against a wide range of insects. As EPN is expected to be released released to the environment primarily during aerial and ground spraying of various agricultural crops. When released to in water or the soil it is expected to be degraded rapidly (in less than a month) by hydrolysis and oxidation. Due to it's low water solubility it is expected to be relative immobile in the soils where it's sprayed upon. In water it is also mostly adsorbed to suspended particles and sediments. It has a low volatility, causing only small amounts to evaporate to the atmosphere where they are degraded rapidly. 
It is a highly toxic compound for crustaceans, as concentrations above 0,5 µg/l can already be lethal. Fish are less vulnerable as concentrations of 20 µg/l are tolerated, and some fish species can even survive short exposure to concentrations above 1 mg/l. 
Environmental standards and legislation