Lorsban

Chlorpyrifos

Names
IUPAC name O,O-Diethyl O-3,5,6-trichloropyridin-2-yl phosphorothioate
Other names Brodan, Chlorpyrifos-ethyl, Detmol UA, Dowco 179, Dursban, Empire, Eradex, Lorsban, Paqeant, Piridane, Scout, Stipend and Tricel.
Identifiers
CAS Number	2921-88-2 Y
3D model (Jmol)	Interactive image
ChEBI	CHEBI:34631 Y
ChemSpider	2629 Y
ECHA InfoCard	100.018.969
KEGG	D07688 Y
PubChem CID	2730
UNII	JCS58I644W Y
InChI InChI=1S/C9H11Cl3NO3PS/c1-3-14-17(18,15-4-2)16-9-7(11)5-6(10)8(12)13-9/h5H,3-4H2,1-2H3 Y Key: SBPBAQFWLVIOKP-UHFFFAOYSA-N Y InChI=1/C9H11Cl3NO3PS/c1-3-14-17(18,15-4-2)16-9-7(11)5-6(10)8(12)13-9/h5H,3-4H2,1-2H3 Key: SBPBAQFWLVIOKP-UHFFFAOYAG
SMILES Clc1c(OP(=S)(OCC)OCC)nc(Cl)c(Cl)c1
Properties
Chemical formula	C9H11Cl3NO3PS
Molar mass	350.59 g/mol
Appearance	colourless crystals
Odor	mercaptan-like
Density	1.398 g/cm3 (43.5 °C)
Melting point	43 °C (109 °F; 316 K)
Boiling point	160 °C; 320 °F; 433 K (decomposes)
Solubility in water	2 mg/L (25 °C)
log P	4.96 (octanol/water)
Hazards
Main hazards	combustible, reacts strongly with amines, strong acids, caustics
US health exposure limits (NIOSH):
PEL (Permissible)	none
REL (Recommended)	TWA 0.2 mg/m3 ST 0.6 mg/m3 [skin]
IDLH (Immediate danger)	N.D.
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Y  (what is YN ?)
Infobox references

Chlorpyrifos (IUPAC name: O,O-diethyl O-3,5,6-trichloropyridin-2-yl phosphorothioate) is a crystalline organophosphate insecticide, acaracide and miticide. It was introduced in 1965 by Dow Chemical Company and is known by many trade names including Dursban, Lorsban, Bolton Insecticide, Nufos, Cobalt, Hatchet, and Warhawk. It acts on the nervous system of insects by inhibiting acetylcholinesterase.

Chlorpyrifos is moderately toxic to humans, and exposure has been linked to neurological effects, persistent developmental disorders and autoimmune disorders. Exposure during pregnancy retards the mental development of children, and most home use was banned in 2001 in the U.S. In agriculture, it is "one of the most widely used organophosphate insecticides" in the United States, according to the United States Environmental Protection Agency (EPA), and before being phased out for residential use was one of the most used residential insecticides. On March 29, 2017, EPA Administrator Scott Pruitt denied a petition to ban chlorpyrifos.

Chlorpyrifos is produced via a multistep synthesis from 3-methylpyridine, eventually reacting 3,5,6-trichloro-2-pyridinol with diethylthiophosphoryl chloride.

Chlorpyrifos is used around the world to control pest insects in agricultural, residential and commercial settings. Its use in residential applications is restricted in multiple countries. According to Dow, chlorpyrifos is registered for use in nearly 100 countries and is annually applied to approximately 8.5 million crop acres. The crops with the most use are cotton, corn, almonds and fruit trees including oranges, bananas and apples.

Chlorpyrifos was first registered for use in the United States in 1965 for control of foliage and soil-born insects. The chemical became widely used in residential settings, on golf course turf, as a structural termite control agent, and in agricultural use. Most residential use has been phased out in the United States; however it remains a common agricultural insecticide.