... Chlorpyrifos Chemical name: O,O-diethyl-O-(3,5,6-trichloro-2-pyridyl)phosphorothioate CAS NO.: 2921-88 ... Chlorpyrifos Chemical name: O,O-diethyl-O-(3,5,6-trichloro-2-pyridyl)phosphorothioateCAS NO.: 2921-88- ... room temperature.Density: 1.398(43.5°C).Melting Point: 41.5~43.5°C.Vapour Pressure: 2.5mPa(25 ... bees. Acute oral LD50 of 40.7% chlorpyrifos EC for rats 590mg/kg, acute dermal for rabbits LD50 ...