Chlorpyrifos

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
ChEMBL	ChEMBL463210^Y
ChemSpider	2629^Y
ECHA InfoCard	100.018.969
KEGG	D07688^Y
PubChem	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 (see table), including Dursban and Lorsban. 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.

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.

EPA estimated that between 1987 and 1998 about 21 million pounds of chlorpyrifos were annually used in the US. In 2007, chlorpyrifos was the most commonly used organophosphate pesticide in the United States, with an estimated 8 to 11 million pounds applied, and the 14th most common agricultural pesticide ingredient overall in 2007 in the United States.

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Wikipedia