7421-50-3 Ethyl S-(2-ethylthioethyl)methyl phosphorothiolothionate O-Ethyl-S-(2-(ethylthio)ethyl)-O-methyl phosphorodithioic acid ester O-Methyl O-ethyl S-(2-ethylthioethyl) dithiophosphate Phosphorodithioic acid, O-ethyl S-(2-ethylthioethyl) O-methyl ester Terathion Teration Tetrathion