Sulfotep
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Names | |
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Preferred IUPAC name
O1,O1,O3,O3-Tetramethyl 1,3-dithiodiphosphate | |
Other names | |
Identifiers | |
3D model (
JSmol ) |
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ECHA InfoCard
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100.020.905 |
EC Number |
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PubChem CID
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RTECS number
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UNII | |
UN number | 1704 |
CompTox Dashboard (EPA)
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Properties | |
C8H20O5P2S2 | |
Molar mass | 322.31 g·mol−1 |
Appearance | Pale yellow liquid[3] |
Odor | Garlic-like[3] |
Density | 1.196 g/cm3 |
Boiling point | 136 to 139 °C (277 to 282 °F; 409 to 412 K) at 2 mm Hg |
30 mg/L | |
Vapor pressure | 0.0002 mmHg (20°C)[3] |
Hazards[6][7] | |
Occupational safety and health (OHS/OSH): | |
Main hazards
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Poison[4] |
NFPA 704 (fire diamond) | |
Flash point | −18 °C (0 °F; 255 K) |
Lethal dose or concentration (LD, LC): | |
LD50 (median dose)
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22 mg/kg (mouse, oral) 25 mg/kg (rabbit, oral) 5 mg/kg (dog, oral) 5 mg/kg (rat, oral)[5] |
LC50 (median concentration)
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38 mg/m3 (rat, 4 hr) 40 mg/m3 (mouse, 4 hr)[5] |
NIOSH (US health exposure limits): | |
PEL (Permissible)
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TWA 0.2 mg/m3 [skin][3] |
IDLH (Immediate danger) |
10 mg/m3[3] |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Sulfotep (also known as tetraethyldithiopyrophosphate and TEDP
History
Sulfotep was first commercially launched by Bayer in 1946. The first time that tetraethyl dithiopyrophosphate was registered to be used in the
Chemistry
Synthesis
Sulfotep is synthesized by a reaction of
An alternative route to TEPP can be a reaction of diethyl chlorothiophosphate an aqueous solution of sodium bicarbonate (Na2CO3).
Properties
When heated to a temperature that is high enough for sulfotep to
Sulfotep's
The alkaline and neutral hydrolysis of sulfotep results in the release of ethanol, phosphoric acid, and hydrogen sulfide.[19]
Applications
Sulfotep has applications as an
Sulfotep kills
A mixture containing 5% sulfotep at the concentration of 0.5 grams of phosphate per 1000 cubic feet was found in tests in the late 1940s to kill 100% of nonresistant two-spotted spider mites and 68-97% of resistant two-spotted spider mites. Sulfotep aerosols killed 100% of the populations of a large number of insects, but only killed 98% of mealybugs in the same tests.[20] 88% of nonresistant spider mites can be killed be two minutes of exposure to a mixture containing 5% of the chemical, 98-99% can be killed after five to ten minutes, and all can be killed after 15 minutes.[23]
Mechanism of action
Sulfotep, just as all organophosphate pesticides, irreversibly inactivates acetylcholinesterase, which is essential to nerve function in insects, humans, and many other animals. Acetylcholinesterase normally hydrolyses acetylcholine after it was released in the synapse. When the acetylcholine is not degraded, it accumulates in the synaptic cleft. Thus, it keeps on stimulating the nerve.[24]
Metabolism
![](http://upload.wikimedia.org/wikipedia/commons/thumb/d/d5/Sulfotep_metabolites.png/400px-Sulfotep_metabolites.png)
Uptake
Sulfotep is taken up well both orally, dermally as well as through inhalation. A few different organizations determined a maximum concentration sulfotep in the air. The maximum allowed concentration is 0.2 mg/m3.
Phase I
Sulfotep is desulfurated by either cytochrome P450 or the FAD-containing monooxygenases. In this reaction, the sulfur is replaced by oxygen, as seen in figure 2. The metabolites formed are monosulfotep and tetraethyl pyrophosphate (TEPP). To accomplish these reactions, a phospho-oxithirane ring is formed, which is highly reactive. This ring is thought to bind to acetylcholinesterase and cause toxicity.[25]
Phase II
The two Phase I metabolites are further transformed through a hydrolysis-reaction mediated by a type A-esterase. The products formed are O,O-diethyldithiophosphate and O,O-diethylphosphate.[25]
Excretion
An experiment in rats who were once given 0.4 mg radioactive phosphor-labelled sulfotep orally, has shown that sulfotep is excreted by both the kidneys (urine) and the liver (bile). The substance is completely metabolised. Two metabolites are found in the urine and faeces. The radioactivity showed that 85-91% was excreted in urine and 5-6% in the faeces.[24]
- 88-96% metabolite 1: O,O-diethyldithiophosphate
- 4-12% metabolite 2: O,O-diethylphosphate [2]
Toxicity
Acute toxic effects on animals
Sulfotep is toxic to some wildlife, including
Exposure | Toxic level |
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Inhalation | mg/m3 |
Mouse 1 hr | 155 [2][26] |
Mouse 4 hr | 40 [2][26] |
Rat 1 hr | 160-330 [2][26] |
Rat 4 hr | 38-59 [2][26] |
Oral LD50 | mg/kg |
Cat | 3 [2][26][27] |
Dog | 5 [2][26][27] |
Mouse | 21.5-29.4 [2][26][27] |
Rabbit | 25 [2][26][27] |
Rat | 5-13.8 [2][26][27] |
Dermal LD50 | mg/kg |
Rat 4 hr | 262 [2] |
Rat 7 d | 65 [2] |
Intravenous LD50 | μg/kg |
Mouse | 300 [2][27] |
Intramuscular LD50 | μg/kg |
Mouse | 500 [2][27] |
Rat | 55[2][27] |
Intraperitoneal LD50 | μg/kg |
Mouse | 940[2][27] |
Rat | 6600[2][27] |
Subcutaneous LD50 | mg/kg |
Mouse | 8[2][27] |
Surviving animals completely recovered in 1–4 days.
Chronic and sub-chronic toxicity
A long-term exposure to a low concentration showed no toxicity. This was tested in rats. They were exposed to different concentrations of sulfotep. Exposed to the highest concentration of 2.83 mg/m3 for six hours a day, five days a week for 12 weeks, there was no change in appearance, behavior or body weight. The plasma cholinesterase activity decreased and the weight of the lungs of female rats increased. The red blood cell acetylcholinesterase activity was not affected. At lower concentrations, there were no changes at all.
The rats were orally exposed to 0, 5, 10, 20 or 50 ppm sulfotep for three months. Only their plasma cholinesterase activity and RBC acetylcholinesterase activity were decreased. No further symptoms were observed. Dogs who were orally exposed to 0, 0.5, 3, 5, 15 or 75 ppm (equivalent to 0–3.07 mg/kg/day) for 13 weeks, ate less and lost weight. The plasma cholinesterase activity was already affected by a sulfotep concentration of 3 ppm (or higher). Red blood cell-acetylcholinesterase was decreased at 75 ppm. Diarrhea and vomiting occasionally occurred at 15 ppm, but were common at 75 ppm. The brain cholinesterase activity was unaffected.[26]
Poisoning symptoms and treatment
According to the Occupational Safety and Health Administration, the upper limit on exposure of sulfotep to human skin is 0.2 milligrams per cubic meter.[14]
Sulfotep causes an organophosphate poisoning. This means that it had an effect on the activity of cholinesterase. There are differences for the indications of a sulfotep poisoning between inhalation, ingestion, intake by the skin and intake by the eyes. However, examples of poisoned greenhouse workers teach us an overall route of symptoms for a sulfotepp poisoning. Within the first hour after a poisonous intake of sulfotep people often suffer from nausea or headaches. After some hours diarrhea and vomiting may occur. People who inhaled sulfotep are often disorientated and have difficulties to breath. A poisonous dose may lead to a coma or death after 24 hours. The point at 24 hours after the poisoning is very important. If the dose is not lethal, the symptoms will slowly disappear after the point of 24 hours.[28][29]
No embryotoxic or teratogenic effects occurred in tests. Neither were there any signs for carcinogenic effects. It was only mutagenic in one strain of S. typhimurium. In four other bacterial strains as well as in rats and mice it was not mutagenic at all.
There are two cases of acute toxicity known in man. The cholinesterase activity in these people was reduced. It took them 20 respectively 28 days to recover.[26] The most important poisoning symptoms are shown in the following table.[30]
Exposure | Symptoms | First aid treatment | Other treatments |
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Inhalation | blue skin, convulsions, dizziness, drowsiness, headache, sweating, labored breathing, nausea, unconsciousness, weakness | Fresh air or artificial respiration. Rest is important to prevent a respiration-arrest | |
Ingestion | cramps in intestines, diarrhea, vomiting, confusion | Vomiting may only be induced in conscious people | Active charcoal to absorb compound. Atropine as an antidote |
Eyes | irritation, redness, constriction of the pupil, loss of focus | Rinsing with plenty of water will lead to recovery of sight within 24 hours | |
Skin (may be absorbed) | redness, irritation, sweating, twitching of the area | First rinse with plenty of water. Then wash the skin with water and soap |
References
- ^ Eula Bingham, Barbara Cohrssen, and Charles H. Powell. Patty's toxicology. Vol. 7 (5th ed.). John Wiley and Sons.
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: CS1 maint: multiple names: authors list (link) - ^ a b c d e f g h i j k l m n o p q r s CID 19395 from PubChem
- ^ a b c d e NIOSH Pocket Guide to Chemical Hazards. "#0586". National Institute for Occupational Safety and Health (NIOSH).
- ^ Sulfotep toxicity
- ^ a b "TEDP". Immediately Dangerous to Life or Health Concentrations (IDLH). National Institute for Occupational Safety and Health (NIOSH).
- ^ Product detail chemkoo.com [dead link]
- ^ a b Georg Kimmerle and Otto R. Klimmer, ‘’Acute and Subchronic Toxicity of Sulfotep’’, Arch. Toxicol. 33, 1-16 (1974)
- ^ a b c d Tetraethyl dithiopyrophosphate, retrieved July 30, 2013
- ^ a b c d e f TETRAETHYL DITHIOPYROPHOSPHATE, retrieved July 29, 2013
- ^ a b c Sulfotepp (PDF), October 1999, retrieved July 31, 2013
- PMID 18102975.
- ^ Thomas A. Unger, Pesticide synthesis handbook – page 387
- ^ a b c OSHA/EPA Occupational Chemical Database, retrieved February 15, 2017
- ^ ISBN 9781420009132
- ^ Tetraethyl dithiopyrophosphate, retrieved July 30, 2013
- ^ TETRAETHYL DITHIOPYROPHOSPHATE, retrieved July 31, 2013
- ISBN 9780873716536
- )
- ^ a b Floyd F. Smith, R.A. Fulton (June 1950), Tetraethyl dithiophosphate in Aerosols for the Control of Greenhouse Insects, Washington, D.C. : U.S. Department of Agriculture, Agricultural Research Administration, Bureau of Entomology and Plant Quarantine
- ^ Haz-Map, April 2013, retrieved July 31, 2013
- ^ a b Floyd F. Smith, R.A. Fulton (June 1950), Tetraethyl dithiophosphate in Aerosols for the Control of Greenhouse Insects, Washington, D.C. : U.S. Department of Agriculture, Agricultural Research Administration, Bureau of Entomology and Plant Quarantine
- ^ a b Floyd F. Smith, R.A. Fulton (June 1950), Tetraethyl dithiophosphate in Aerosols for the Control of Greenhouse Insects, Washington, D.C. : U.S. Department of Agriculture, Agricultural Research Administration, Bureau of Entomology and Plant Quarantine
- ^ a b Sulfotep, Bayer MAK 24, Lieferung 1997
- ^ a b Timbrell John A., Principles of biochemical toxicology 4th edition 2009. Informa Healthcare New York. pp 91 & 99
- ^ a b c d e f g h i j k Eula Bingham, Barbara Cohrssen and Charles H. Powell. Patty’s toxicology (5th edition. Vol. 7. John Wiley and sons inc.)
- ^ a b c d e f g h i j k Richard J. Lewis, Sr. Sax’s Dangerous properties of industrial materials (10th edition. Vol. 3. John Wiley and sons inc.)
- ^ "ICSC:NDUT0985 International Chemical Safety Cards (WHO/IPCS/ILO) | CDC/NIOSH". www.cdc.gov. Archived from the original on 2008-01-24.
- ^ Chemwatch, Sulfotep sc-251093. Material Safety Data Sheet. https://datasheets.scbt.com/sc-251093.pdf
- ^ International Chemical Safety Cards, ICSC: 0985, https://www.cdc.gov/niosh/ipcsndut/ndut0985.html
External links
- Sulfotep in the Pesticide Properties DataBase (PPDB)