ContaminantDB: Fenthion

Identification Taxonomy Biological Properties Physical Properties Toxicity Profile Spectra Concentrations Links References Targets (13)XML

Record Information

Version

1.0

Creation Date

2009-07-30 17:58:52 UTC

Update Date

2026-03-25 19:18:17 UTC

Accession Number

CHEM002515

Identification

Common Name

Fenthion

Class

Small Molecule

Description

Fenthion is an organophosphate used primarily as an insecticide and secondarily as an avicide and acaricide. It was used extensively preharvest on sugar cane, rice, field corn, beets, pome and stone fruit, citrus fruits, pistachio, cotton, olives, coffee, cocoa, vegetables, and vines. However, fenthion no longer has Food and Drug Administration approval because of an excess number of poisoning related deaths (occur mostly by ingestion). Fenthion is neurotoxic. (4) (5)

Contaminant Sources

Clean Air Act Chemicals
FooDB Chemicals
HPV EPA Chemicals
My Exposome Chemicals
STOFF IDENT Compounds
T3DB toxins
ToxCast & Tox21 Chemicals

Contaminant Type

Ester
Ether
Food Toxin
Organic Compound
Organophosphate
Pesticide
Synthetic Compound

Chemical Structure

MOL SDF PDB SMILES InChI

Synonyms

Value	Source
4-Methylmercapto-3-methylphenyl dimethyl thiophosphate	ChEBI
Mercaptophos	ChEBI
MPP	ChEBI
O,O-Dimethyl O-4-(methylmercapto)-3-methylphenyl phosphorothioate	ChEBI
O,O-Dimethyl O-4-methylthio-m-tolyl phosphorothioate	ChEBI
O,O-Dimethyl O-[3-methyl-4-(methylsulfanyl)phenyl] thiophosphate	ChEBI
O,O-Dimethyl-O-4-(methylmercapto)-3-methylphenyl thiophosphate	ChEBI
Phosphorothioic acid, O,O-dimethyl O-(3-methyl-4-(methylthio)phenyl) ester	ChEBI
Tiguvon	Kegg
4-Methylmercapto-3-methylphenyl dimethyl thiophosphoric acid	Generator
O,O-Dimethyl O-4-(methylmercapto)-3-methylphenyl phosphorothioic acid	Generator
O,O-Dimethyl O-4-methylthio-m-tolyl phosphorothioic acid	Generator
O,O-Dimethyl O-[3-methyl-4-(methylsulfanyl)phenyl] thiophosphoric acid	Generator
O,O-Dimethyl O-[3-methyl-4-(methylsulphanyl)phenyl] thiophosphate	Generator
O,O-Dimethyl O-[3-methyl-4-(methylsulphanyl)phenyl] thiophosphoric acid	Generator
O,O-Dimethyl-O-4-(methylmercapto)-3-methylphenyl thiophosphoric acid	Generator
Phosphorothioate, O,O-dimethyl O-(3-methyl-4-(methylthio)phenyl) ester	Generator
Bayer 29493	HMDB
Baytex	HMDB, MeSH
Dimethyl (3-methyl-4-(methylthio)phenyl) phosphorothionate	HMDB
Dimethyl methylthiotolyl phosphorothioate	HMDB
Dimethyl O-(3-methyl-4-(methylthio)phenyl) thiophosphate	HMDB
Dimethyl O-(4-(methylthio)-m-tolyl) phosphorothioate	HMDB
DMTP	HMDB
ent 25540	HMDB
Entex	HMDB
Fenthione	HMDB
Figuron	HMDB
Lebaycid	HMDB, MeSH
Lebayeid	HMDB
Mosquitocide 700	HMDB
MPP (Pesticide)	HMDB
O,O-Dimethyl O-(4-methylthio-3-methylphenyl) thiophosphate	HMDB
O,O-Dimethyl O-[(3-methyl-4-methylthio)phenyl] phosphorothioate, 9ci	HMDB
O,O-Dimethyl-O-[4-(methylthio)-m-tolyl] phosphorothioate	HMDB
Phenthion	HMDB
Queletox	HMDB
Spotton	HMDB
Talodex	HMDB

Chemical Formula

C₁₀H₁₅O₃PS₂

Average Molecular Mass

278.328 g/mol

Monoisotopic Mass

278.020 g/mol

CAS Registry Number

55-38-9

IUPAC Name

O,O-dimethyl O-3-methyl-4-(methylsulfanyl)phenyl phosphorothioate

Traditional Name

fenthion

SMILES

COP(=S)(OC)OC1=CC=C(SC)C(C)=C1

InChI Identifier

InChI=1S/C10H15O3PS2/c1-8-7-9(5-6-10(8)16-4)13-14(15,11-2)12-3/h5-7H,1-4H3

InChI Key

PNVJTZOFSHSLTO-UHFFFAOYSA-N

Chemical Taxonomy

Description

belongs to the class of organic compounds known as phenyl thiophosphates. These are organothiophosphorus compounds that contain a thiophosphoric acid O-esterified with a phenyl group.

Kingdom

Organic compounds

Super Class

Organic acids and derivatives

Class

Organic thiophosphoric acids and derivatives

Sub Class

Thiophosphoric acid esters

Direct Parent

Phenyl thiophosphates

Alternative Parents

Substituents

Phenyl thiophosphate
Phenoxy compound
Aryl thioether
Thiophosphate triester
Thiophenol ether
Toluene
Alkylarylthioether
Monocyclic benzene moiety
Benzenoid
Thioether
Sulfenyl compound
Organosulfur compound
Organooxygen compound
Hydrocarbon derivative
Organic oxygen compound
Aromatic homomonocyclic compound

Molecular Framework

Aromatic homomonocyclic compounds

External Descriptors

organic thiophosphate (CHEBI:34761 )
Organophosphorus insecticides (C14420 )

Biological Properties

Status

Detected and Not Quantified

Origin

Exogenous

Cellular Locations

Membrane

Biofluid Locations

Not Available

Tissue Locations

Not Available

Pathways

Not Available

Applications

Biological Roles

Chemical Roles

Physical Properties

State

Liquid

Appearance

Colourless oily liquid with characteristic odour. (3)

Experimental Properties

Property	Value
Melting Point	7.5°C
Boiling Point	87 °C (at 0.01 mmHg)
Solubility	54-56 ppm (at 20 °C)

Predicted Properties

Property	Value	Source
Water Solubility	0.0042 g/L	ALOGPS
logP	3.93	ALOGPS
logP	3.8	ChemAxon
logS	-4.8	ALOGPS
Physiological Charge	0	ChemAxon
Hydrogen Acceptor Count	0	ChemAxon
Hydrogen Donor Count	0	ChemAxon
Polar Surface Area	27.69 Å²	ChemAxon
Rotatable Bond Count	5	ChemAxon
Refractivity	73.67 m³·mol⁻¹	ChemAxon
Polarizability	27.22 Å³	ChemAxon
Number of Rings	1	ChemAxon
Bioavailability	1	ChemAxon
Rule of Five	Yes	ChemAxon
Ghose Filter	Yes	ChemAxon
Veber's Rule	Yes	ChemAxon
MDDR-like Rule	No	ChemAxon

Spectra

Spectrum Type	Description	Splash Key	View
GC-MS	GC-MS Spectrum - EI-B (Non-derivatized)	splash10-00os-4930000000-d917f6fe7c279d0326ef	Spectrum
GC-MS	GC-MS Spectrum - EI-B (Non-derivatized)	splash10-00os-4930000000-d917f6fe7c279d0326ef	Spectrum
Predicted GC-MS	Predicted GC-MS Spectrum - GC-MS (Non-derivatized) - 70eV, Positive	splash10-0ik9-1970000000-38f4eb65b0f142b27c42	Spectrum
Predicted GC-MS	Predicted GC-MS Spectrum - GC-MS (Non-derivatized) - 70eV, Positive	Not Available	Spectrum
Predicted GC-MS	Predicted GC-MS Spectrum - GC-MS (Non-derivatized) - 70eV, Positive	Not Available	Spectrum
LC-MS/MS	LC-MS/MS Spectrum - LC-ESI-QTOF , positive	splash10-004i-0090000000-cfc6cc7271f15039d91e	Spectrum
LC-MS/MS	LC-MS/MS Spectrum - LC-ESI-QTOF , positive	splash10-014j-0940000000-4c4cfaec8b9d90f02220	Spectrum
LC-MS/MS	LC-MS/MS Spectrum - LC-ESI-QTOF , positive	splash10-0gb9-0910000000-30762456be8c99676446	Spectrum
LC-MS/MS	LC-MS/MS Spectrum - LC-ESI-QTOF , positive	splash10-0gi0-0900000000-fc2e0d1f56a644607b35	Spectrum
LC-MS/MS	LC-MS/MS Spectrum - LC-ESI-QTOF , positive	splash10-0g4i-0900000000-89a0ce8c9a4d4a49d57c	Spectrum
LC-MS/MS	LC-MS/MS Spectrum - LC-ESI-QFT , positive	splash10-001i-0290000000-9da11dc2725fc111b8c4	Spectrum
LC-MS/MS	LC-MS/MS Spectrum - 20V, Positive	splash10-014j-0940000000-199b003861522f4b62e1	Spectrum
LC-MS/MS	LC-MS/MS Spectrum - 30V, Positive	splash10-0gb9-0910000000-14a50b7ed49de35229bc	Spectrum
LC-MS/MS	LC-MS/MS Spectrum - 40V, Positive	splash10-0gi0-0900000000-fc2e0d1f56a644607b35	Spectrum
LC-MS/MS	LC-MS/MS Spectrum - 50V, Positive	splash10-0g4i-0900000000-daf8e3082dcd599a9ef6	Spectrum
LC-MS/MS	LC-MS/MS Spectrum - 50V, Positive	splash10-0g4i-0900000000-677923a06bbdab3e4faa	Spectrum
LC-MS/MS	LC-MS/MS Spectrum - 30V, Positive	splash10-0v4i-0910000000-d74e5478dcae4fb77f71	Spectrum
LC-MS/MS	LC-MS/MS Spectrum - 40V, Positive	splash10-0g4i-0900000000-c7ed3dac5d73de1abfe2	Spectrum
LC-MS/MS	LC-MS/MS Spectrum - 35V, Positive	splash10-001i-0290000000-c4282f269db3a3c433b7	Spectrum
LC-MS/MS	LC-MS/MS Spectrum - 20V, Positive	splash10-014j-0940000000-49b2bd577f2239e1eeed	Spectrum
LC-MS/MS	LC-MS/MS Spectrum - 10V, Positive	splash10-004i-0090000000-03e61a06874c5e65189c	Spectrum
LC-MS/MS	LC-MS/MS Spectrum - 50V, Positive	splash10-0g4i-0900000000-89a0ce8c9a4d4a49d57c	Spectrum
Predicted LC-MS/MS	Predicted LC-MS/MS Spectrum - 10V, Positive	splash10-004i-0190000000-74fefa9007324dd9847e	Spectrum
Predicted LC-MS/MS	Predicted LC-MS/MS Spectrum - 20V, Positive	splash10-002r-1970000000-6492e585fe189b3d02a0	Spectrum
Predicted LC-MS/MS	Predicted LC-MS/MS Spectrum - 40V, Positive	splash10-01pc-9880000000-8949ee35385684bf0416	Spectrum
Predicted LC-MS/MS	Predicted LC-MS/MS Spectrum - 10V, Negative	splash10-005c-0290000000-b55d858a805aaba2db82	Spectrum
Predicted LC-MS/MS	Predicted LC-MS/MS Spectrum - 20V, Negative	splash10-003r-0290000000-6e342595466184c4595b	Spectrum
Predicted LC-MS/MS	Predicted LC-MS/MS Spectrum - 40V, Negative	splash10-0a4l-2900000000-eb2a165616e3235fce1d	Spectrum
Predicted LC-MS/MS	Predicted LC-MS/MS Spectrum - 10V, Positive	splash10-004i-0190000000-953bec3de0724b9038a4	Spectrum
Predicted LC-MS/MS	Predicted LC-MS/MS Spectrum - 20V, Positive	splash10-004u-4790000000-c6f5d3f2adc0c2093b0b	Spectrum
MS	Mass Spectrum (Electron Ionization)	splash10-004i-7970000000-bc43a51c3e0e0f2a8537	Spectrum
1D NMR	1H NMR Spectrum	Not Available	Spectrum
1D NMR	13C NMR Spectrum	Not Available	Spectrum

Toxicity Profile

Route of Exposure

Oral (L1681

Mechanism of Toxicity

Fenthion is a cholinesterase or acetylcholinesterase (AChE) inhibitor. A cholinesterase inhibitor (or 'anticholinesterase') suppresses the action of acetylcholinesterase. Because of its essential function, chemicals that interfere with the action of acetylcholinesterase are potent neurotoxins, causing excessive salivation and eye-watering in low doses, followed by muscle spasms and ultimately death. Nerve gases and many substances used in insecticides have been shown to act by binding a serine in the active site of acetylcholine esterase, inhibiting the enzyme completely. Acetylcholine esterase breaks down the neurotransmitter acetylcholine, which is released at nerve and muscle junctions, in order to allow the muscle or organ to relax. The result of acetylcholine esterase inhibition is that acetylcholine builds up and continues to act so that any nerve impulses are continually transmitted and muscle contractions do not stop. Among the most common acetylcholinesterase inhibitors are phosphorus-based compounds, which are designed to bind to the active site of the enzyme. The structural requirements are a phosphorus atom bearing two lipophilic groups, a leaving group (such as a halide or thiocyanate), and a terminal oxygen.

Metabolism

Metabolism of organophosphates occurs principally by oxidation, by hydrolysis via esterases and by reaction with glutathione. Demethylation and glucuronidation may also occur. Oxidation of organophosphorus pesticides may result in moderately toxic products. In general, phosphorothioates are not directly toxic but require oxidative metabolism to the proximal toxin. The glutathione transferase reactions produce products that are, in most cases, of low toxicity. Paraoxonase (PON1) is a key enzyme in the metabolism of organophosphates. PON1 can inactivate some organophosphates through hydrolysis. PON1 hydrolyzes the active metabolites in several organophosphates insecticides as well as, nerve agents such as soman, sarin, and VX. The presence of PON1 polymorphisms causes there to be different enzyme levels and catalytic efficiency of this esterase, which in turn suggests that different individuals may be more susceptible to the toxic effect of organophosphate exposure.

Toxicity Values

LD50: 330 mg/kg (Dermal, Rat) (4) LD50: 190 to 615 mg/kg (Oral, Rat) (4)

Lethal Dose

Not Available

Carcinogenicity (IARC Classification)

Spraying and application of nonarsenical insecticides entail exposures that are probably carcinogenic to humans (Group 2A). (2)

Uses/Sources

The general population is not likely to be exposed to large amounts of fenthion. Occupational exposure to fenthion occurs through dermal contact and inhalation of dust and sprays, especially to workers applying the compound as an insecticide. Because fenthion has been detected in American foods, exposure to the general population can occur through consumption of foods containing fenthion residues. (4)

Minimum Risk Level

Not Available

Health Effects

Acute exposure to cholinesterase inhibitors can cause a cholinergic crisis characterized by severe nausea/vomiting, salivation, sweating, bradycardia, hypotension, collapse, and convulsions. Increasing muscle weakness is a possibility and may result in death if respiratory muscles are involved. Accumulation of ACh at motor nerves causes overstimulation of nicotinic expression at the neuromuscular junction. When this occurs symptoms such as muscle weakness, fatigue, muscle cramps, fasciculation, and paralysis can be seen. When there is an accumulation of ACh at autonomic ganglia this causes overstimulation of nicotinic expression in the sympathetic system. Symptoms associated with this are hypertension, and hypoglycemia. Overstimulation of nicotinic acetylcholine receptors in the central nervous system, due to accumulation of ACh, results in anxiety, headache, convulsions, ataxia, depression of respiration and circulation, tremor, general weakness, and potentially coma. When there is expression of muscarinic overstimulation due to excess acetylcholine at muscarinic acetylcholine receptors symptoms of visual disturbances, tightness in chest, wheezing due to bronchoconstriction, increased bronchial secretions, increased salivation, lacrimation, sweating, peristalsis, and urination can occur. Certain reproductive effects in fertility, growth, and development for males and females have been linked specifically to organophosphate pesticide exposure. Most of the research on reproductive effects has been conducted on farmers working with pesticides and insecticdes in rural areas. In females menstrual cycle disturbances, longer pregnancies, spontaneous abortions, stillbirths, and some developmental effects in offspring have been linked to organophosphate pesticide exposure. Prenatal exposure has been linked to impaired fetal growth and development. Neurotoxic effects have also been linked to poisoning with OP pesticides causing four neurotoxic effects in humans: cholinergic syndrome, intermediate syndrome, organophosphate-induced delayed polyneuropathy (OPIDP), and chronic organophosphate-induced neuropsychiatric disorder (COPIND). These syndromes result after acute and chronic exposure to OP pesticides.

Symptoms

The symptoms after inhalation and skin contact are: dizziness, nausea, vomiting, sweating, pupillary constriction, muscle cramp, excessive salivation, laboured breathing, convulsions, unconsciousness. The same symptoms occur after ingestion, with additionally abdominal cramps, diarrhoea, nausea and vomiting. In case of eye contact, blurred vision occurs. (3)

Treatment

If the compound has been ingested, rapid gastric lavage should be performed using 5% sodium bicarbonate. For skin contact, the skin should be washed with soap and water. If the compound has entered the eyes, they should be washed with large quantities of isotonic saline or water. In serious cases, atropine and/or pralidoxime should be administered. Anti-cholinergic drugs work to counteract the effects of excess acetylcholine and reactivate AChE. Atropine can be used as an antidote in conjunction with pralidoxime or other pyridinium oximes (such as trimedoxime or obidoxime), though the use of '-oximes' has been found to be of no benefit, or possibly harmful, in at least two meta-analyses. Atropine is a muscarinic antagonist, and thus blocks the action of acetylcholine peripherally.

Concentrations

Not Available

External Links

DrugBank ID

DB11412

HMDB ID

HMDB0033209

FooDB ID

FDB011222

Phenol Explorer ID

Not Available

KNApSAcK ID