An organic thiophosphate that is O,O-dimethyl O-phenyl phosphorothioate substituted by a methyl group at position 3 and a nitro group at position 4. ChEBI: Fenitrothion is an organic thiophosphate that is O,O-dimethyl O-phenyl phosphorothioate substituted by a methyl group at position 3 and a nitro group at position 4. It has a role as an EC 3.1.1.7 (acetylcholinesterase) inhibitor, an agrochemical, an acaricide, an EC 3.1.1.8 (cholinesterase) inhibitor and an insecticide. It is an organic thiophosphate and a C-nitro compound. It is functionally related to a 4-nitro-m-cresol.