Leptophos

Structural formula
General
Surname	Leptophos
other names	O - (4-Bromo-2,5-dichlorophenyl) - O -methylphenylphosphonothioate; Abar; Phosvel; Velsicol 506;
Molecular formula	C 13 H 10 BrCl 2 O 2 PS
Brief description	white to light brown solid
External identifiers / databases
EC number	244-472-8
ECHA InfoCard	100.040.415
PubChem	30709
Wikidata	Q6528275
properties
Molar mass	412.07 g mol −1
Physical state	firmly
density	1.53 g cm −3
Melting point	71-73 ° C
boiling point	Decomposition from 180 ° C
solubility	practically insoluble in water
safety instructions
H and P phrases	H: 301-312-370-410
	P: 260-273-307 + 311-501
Toxicological data	19 mg kg −1 ( LD 50 , rat , oral ) ; 800 mg kg −1 ( LD 50 , rabbit , transdermal ) ;
	As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Leptophos is a chemical compound from the group of thiophosphonic acid esters , which was produced by Velsicol until it was banned in the USA in 1976.

Extraction and presentation

Leptophos can be obtained by reacting O -methylphenylthiophosponyl chloride and 4-bromo-2,5-dichlorophenol :

C ₇ H ₈ ClOPS + C ₆ H ₃ BrCl ₂ O → C ₁₃ H ₁₀ BrCl ₂ O ₂ PS + HCl.

use

Leptophos was used as an insecticide . The effect is based on the inhibition of cholinesterases .

Admission

In the United States, Leptophos had been approved for a limited period since 1971. Media reports about drowsiness, visual disturbances and paralysis among workers in the Leptophos production caused a sensation in 1976. Sometimes these workers were referred to as "Phosvel zombies". Leptophos was exported to many other states. In Egypt, 1,200 water buffalo died of Leptophos poisoning. The 1976 Toxic Substances Control Act (TCSA) banned the manufacture of unregistered chemicals.

Leptophos is not approved as a crop protection agent in the European Union or Switzerland .

Degradation routes

Individual evidence

↑ ^a ^b ^c ^d ^e ^f ^g ^h Entry on Leptophos in the GESTIS substance database of the IFA , accessed on February 7, 2017(JavaScript required) .
↑ Leptophos data sheet , PESTANAL at Sigma-Aldrich , accessed on October 18, 2016 ( PDF ).
↑ Entry on Leptophos in the Classification and Labeling Inventory of the European Chemicals Agency (ECHA), accessed on August 1, 2016. Manufacturers or distributors can expand the harmonized classification and labeling .
↑ David Weir, Mark Schapiro: Circle of Poison: Pesticides and People in a Hungry World . Food First , 1981, p. 23 ( limited preview in Google Book search).
↑ David Kinkela: DDT and the American century , The University of North Carolina Press, Chapel Hill, 2011, pp 175th
^ Directorate-General for Health and Food Safety of the European Commission: EU pesticide database ; Entry in the national directory of plant protection products in Switzerland ; Retrieved June 25, 2016.

[GESTIS-1] ↑ ^a ^b ^c ^d ^e ^f ^g ^h Entry on Leptophos in the GESTIS substance database of the IFA , accessed on February 7, 2017(JavaScript required) .

[Sigma-2] Leptophos data sheet , PESTANAL at Sigma-Aldrich , accessed on October 18, 2016 ( PDF ).

[CLP_100.040.415-3] Entry on Leptophos in the Classification and Labeling Inventory of the European Chemicals Agency (ECHA), accessed on August 1, 2016. Manufacturers or distributors can expand the harmonized classification and labeling .

[4] David Weir, Mark Schapiro: Circle of Poison: Pesticides and People in a Hungry World . Food First , 1981, p. 23 ( limited preview in Google Book search).

[5] David Kinkela: DDT and the American century , The University of North Carolina Press, Chapel Hill, 2011, pp 175th

[6] Directorate-General for Health and Food Safety of the European Commission: EU pesticide database ; Entry in the national directory of plant protection products in Switzerland ; Retrieved June 25, 2016.