CAS number 333-41-5 YesY
PubChem 3017
ChemSpider 2909 YesY
KEGG D07856 YesY
ChEBI CHEBI:34682 YesY
Jmol-3D images Image 1
Molecular formula C12H21N2O3PS
Molar mass 304.35 g/mol
Appearance Colorless to dark brown liquid
Density 1.116-1.118 g/cm3 at 20 °C[1]
Solubility in water 40 mg/L at 25 °C[2]
log P 3.81 (octanol/water)[3]
 YesY (verify) (what is: YesY/N?)
Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

Diazinon (IUPAC name: O,O-Diethyl O-[4-methyl-6-(propan-2-yl)pyrimidin-2-yl] phosphorothioate), a colorless to dark brown liquid, is a thiophosphoric acid ester developed in 1952 by Ciba-Geigy, a Swiss chemical company (later Novartis and then Syngenta). It is a nonsystemic organophosphate insecticide formerly used to control cockroaches, silverfish, ants, and fleas in residential, non-food buildings. Diazinon was heavily used during the 1970s and early 1980s for general-purpose gardening use and indoor pest control. A bait form was used to control scavenger wasps in the western U.S. Residential uses of diazinon were outlawed in the U.S. in 2004 but it is still approved for agricultural uses.

Diazinon kills insects by inhibiting acetylcholinesterase, an enzyme necessary for proper nervous system function. Diazinon has a low persistence in soil. The half-life is 2 to 6 weeks.[4] The symptoms associated with diazinon poisoning in humans include weakness, headaches, tightness in the chest, blurred vision, nonreactive pinpoint pupils, excessive salivation, sweating, nausea, vomiting, diarrhea, abdominal cramps, and slurred speech.

In 1988, the Environmental Protection Agency prohibited the use of Diazinon on golf courses and sod farms because of decimation of bird flocks that congregated in these areas. In the United States as of December 31, 2004, it became unlawful to sell outdoor, non-agricultural products containing diazinon. It is still legal for consumers to use diazinon products purchased before this date, provided that they follow all label directions and precautions.


  1. ^ Budavari, S. (ed.). The Merck Index - An Encyclopedia of Chemicals, Drugs, and Biologicals. Whitehouse Station, NJ: Merck and Co., Inc., 1996., p. 508
  2. ^ Sharom MS et al; Water Res 14: 1095-100 (1980)
  3. ^ Hansch, C., Leo, A., D. Hoekman. Exploring QSAR - Hydrophobic, Electronic, and Steric Constants. Washington, DC: American Chemical Society., 1995., p. 106
  4. ^ Diazinon at pesticideinfo.org

External links