Parathion

Parathion

Names
IUPAC name O,O-Diethyl O-(4-nitrophenyl) phosphorothioate
Other names E605
Identifiers
CAS Number	56-38-2 Y
3D model (Jmol)	Interactive image
ChEBI	CHEBI:27928 N
ChEMBL	ChEMBL261919 Y
ChemSpider	13844817 Y
ECHA InfoCard	100.000.247
KEGG	C06604 Y
UNII	61G466064D Y
InChI InChI=1S/C10H14NO5PS/c1-3-14-17(18,15-4-2)16-10-7-5-9(6-8-10)11(12)13/h5-8H,3-4H2,1-2H3 Y Key: LCCNCVORNKJIRZ-UHFFFAOYSA-N Y InChI=1/C10H14NO5PS/c1-3-14-17(18,15-4-2)16-10-7-5-9(6-8-10)11(12)13/h5-8H,3-4H2,1-2H3 Key: LCCNCVORNKJIRZ-UHFFFAOYAR
SMILES S=P(Oc1ccc(cc1)[N+]([O-])=O)(OCC)OCC
Properties
Chemical formula	C10H14NO5PS
Molar mass	291.26 g·mol−1
Appearance	White crystals (pure form)
Melting point	6 °C (43 °F; 279 K)
Solubility in water	24 mg/L
Solubility in other solvents	high solubility in xylene and butanol
Hazards
Safety data sheet	[1]
EU classification (DSD)	T+ N
R-phrases	R24, R26/28, R48/25, R50/53
S-phrases	S28, S36/37, S45, S60, S61
NFPA 704	1 4 2
Flash point	120 °C (248 °F; 393 K)
Lethal dose or concentration (LD, LC):
LD50 (median dose)	5 mg/kg (mouse, oral) 10 mg/kg (rabbit, oral) 3 mg/kg (dog, oral) 0.93 mg/kg (cat, oral) 5 mg/kg (horse, oral) 8 mg/kg (guinea pig, oral) 2 mg/kg (rat, oral)
LC50 (median concentration)	84 mg/m3 (rat, 4 hr)
LCLo (lowest published)	50 mg/m3 (rabbit, 2 hr) 14 mg/m3 (guinea pig, 2 hr) 15 mg/m3 (mouse)
US health exposure limits (NIOSH):
PEL (Permissible)	none (methyl parathion), TWA 0.1 mg/m3 [skin] (ethyl parathion)
REL (Recommended)	TWA 0.2 mg/m3 [skin] (methyl parathion) TWA 0.05 mg/m3 [skin] (ethyl parathion)
IDLH (Immediate danger)	N.D. (methyl parathion) 10 mg/m3 (ethyl parathion)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
N  (what is YN ?)
Infobox references

in xylene and butanol

Parathion, also called parathion-ethyl or diethyl parathion and locally known as "Folidol", is an organophosphate compound possessing a organothiophosphate group. It is a potent insecticide and acaricide. It was originally developed by IG Farben in the 1940s. It is highly toxic to non-target organisms, including humans. Its use is banned or restricted in many countries, and there are proposals to ban it from all use. The basic structure is shared by parathion methyl.

Parathion was developed by Gerhard Schrader for the German trust IG Farben in the 1940s. After the war and the collapse of IG Farben due to the war crime trials, the Western allies seized the patent, and parathion was marketed worldwide by different companies and under different brand names. The most common German brand was E605 (banned in Germany after 2002); this was not a food-additive "E number" as used in the EU today. "E" stands for Entwicklungsnummer (German for "development number"). It is an irreversible acetylcholinesterase inhibitor.

Safety concerns have later lead to the development of parathion methyl, which is somewhat less toxic.

When pure, parathion is a white crystalline solid. It is commonly distributed as a brown liquid that smells of rotting eggs or garlic. The insecticide is somewhat stable, although it darkens when exposed to sunlight.

Parathion is synthesized from diethyl dithiophosphoric acid (C₂H₅O)₂PS₂H by chlorination to generate diethylthiophosphoryl chloride ((C₂H₅O)₂P(S)Cl). In a salt metathesis reaction, the chloride treated with sodium 4-nitrophenolate (the sodium salt of 4-nitrophenol).