 | |
| Names | |
|---|---|
| Preferred IUPAC name O,O′-DiethylS-[2-(ethylsulfanyl)ethyl] phosphorodithioate | |
| Other names O,O-DiethylS-2-(ethylthio)ethyl phosphorodithioate, Di-Syston, Thiodemeton | |
| Identifiers | |
| |
3D model (JSmol) | |
| 1709167 | |
| ChEBI | |
| ChEMBL | |
| ChemSpider |
|
| ECHA InfoCard | 100.005.505 |
| EC Number |
|
| KEGG |
|
| RTECS number |
|
| UNII | |
| UN number | 3018 2783 |
| |
| |
| Properties | |
| C8H19O2PS3 | |
| Molar mass | 274.404 |
| Appearance | Oily, colorless to yellow liquid |
| Odor | Characteristic, sulfurous[1] |
| Density | 1.14 g/mL |
| 0.03% (22.7°C)[1] | |
| Vapor pressure | 0.0002 mmHg (20°C)[1] |
| Hazards | |
| Occupational safety and health (OHS/OSH): | |
Main hazards | Toxic |
| GHS labelling:[2] | |
  | |
| Danger | |
| H300,H310,H410 | |
| P262,P264,P270,P273,P280,P301+P316,P302+P352,P316,P321,P330,P361+P364,P391,P405,P501 | |
| Flash point | > 82 °C; 180 °F; 355 K[1] |
| NIOSH (US health exposure limits): | |
PEL (Permissible) | none[1] |
REL (Recommended) | TWA 0.1 mg/m3 [skin][1] |
IDLH (Immediate danger) | N.D.[1] |
Except where otherwise noted, data are given for materials in theirstandard state (at 25 °C [77 °F], 100 kPa). | |
Disulfoton is anorganophosphateacetylcholinesterase inhibitor used as aninsecticide. It is manufactured under the name Di-Syston byBayer CropScience. Disulfoton in its pure form is a colorless oil but the technical product used in vegetable fields is dark and yellowish with asulfur odor. Disulfoton is processed as a liquid into carrier granules. These granules are mixed with fertilizer and clay to be made into a spike, designed to be driven into the ground. Thepesticide is absorbed over time by the roots and translocated to all parts of the plant. The pesticide acts as acholinesterase inhibitor and gives long lasting control.
The use of the substance has been restricted by theUS government. Bayer, the manufacturer, exited the US market December 31, 2009.[3]
Disulfoton is synthesized by sulfide formation of 2-ethylthioethanol + O,O-diethyl hydrogen phosphorodithioate with beta-chloroethyl thioethylether.[4]
Oxidation of Disulfoton happens rapidly and metabolizes disulfoton intosulfones andsulfoxides, oxidation to oxygen analogs and/orhydrolysis to produce a corresponding phosphorothionate or phosphate. Microsomal enzymes are being inhibited during the metabolism.[5]
Organophosphorus pesticides like Disulfoton inhibit esterase enzyme activity like choline esterase. These types of pesticides can also directly interact with the biochemical receptors ofacetylcholine.
Organophosphates in general poisons mammals and insects by phosphorylating the acetylcholinesterase enzyme at nerve endings resulting in loss of function of the enzyme. This allows the accumulation of the neurotransmitter acetylcholine incholinergicneuroeffector junctions, skeletal myoneural junctions, andautonomic ganglia. This refers to the type of receptors of acetylcholine, themuscarinic andnicotinic effects respectively. Thus organophosphates also impairs nerve impulse transmission.[6][7]
Disulfoton can be absorbed via ingestion, inhalation or penetration of the skin as it can be rapidly absorbed viamucous membranes.[7] When disulfoton is absorbed, it will be distributed via the blood circulation and undergo hydrolytic degradation. This mainly happens in the liver or kidneys but in other tissues as well. Disulfoton is excreted in differentmetabolites via the urine.[6]
Disulfoton is classified as a super toxic substance. The estimated orallethal dose in humans is less than 5 mg/kg, which is analog to seven drops for a 70 kg person.
Not only oral intake, but also skin contact and inhalation are fatal because of acute toxicity. Disulfoton is also very toxic to aquatic life and forms an acute hazard with long lasting effects.
Signs of disulfoton toxicity includes headaches,cyanosis, weakness, fatigue, nausea, vomiting, abdominal cramps, diarrhea, blurred vision, mental confusion, loss of muscle coordination andsialorrhea. Death can occur when respiratory arrest ensues from failure of the respiratory muscles.[8] Other symptoms found in a patient with an unknown quantity of disulfoton were intra-alveolar bleeding, blood in the bronchus, edema of the lungs and swelling of the glomerulus.[9]
The treatment of the granular form of disulfoton poisoning should be with repetitive or prolonged gastric and intestinal lavage (washing out of the body cavity). Also charcoal and a continuous intravenous infusion ofpralidoximeiodide in addition toatropine sulfate.[10]
