55-38-9 Usage
Uses
Used in Agricultural Industry:
Fenthion is used as an insecticide and acaricide for the control of fruit flies, leafhoppers, cereal bugs, stem borers, mosquitoes, animal parasites, mites, aphids, codling moths, and weaverbirds. It is also used for field and post-harvest treatment of various fruits, vegetables, and ornamentals.
Used in Mosquito Control:
Fenthion is used for mosquito control in water and septic tanks, as well as for pest control in commercial and domestic areas.
Used in Veterinary Medicine:
Fenthion has been tested in dogs and cows for possible control of parasites, and is used as an ectoparasiticide in cattle.
Used in Avicide Applications:
Due to its high toxicity to birds, fenthion is used for weaverbird control and to control pigeons around public buildings.
Used as an Antihypertensive:
Fenthion has also been used as an antihypertensive agent.
Mode of action
Fenthion belongs to one of a class of insecticides referred to as organophosphates[1,9]. These chemicals act by interfering with the activities of cholinesterase, an esterase that lyses choline-based esters, several of which serve as neurotransmitters. Thus, it is either of two enzymes that catalyze the hydrolysis of these cholinergic neurotransmitters, such as breaking acetylcholine into choline and acetic acid. These reactions are necessary to allow a cholinergic neuron to return to its resting state after activation. Therefore, it is essential for the proper working of the nervous systems of both humans and insects[10, 11].
Warning and Risk
Fenthion can provide both acute toxicity and chronic toxicity.
Acute toxicity[12]
It is moderately toxic if ingested, inhaled, or absorbed through the skin. It affects the central nervous, cardiovascular, and respiratory systems, and may irritate eyes and mucous membranes. When inhaled, the first effects may include bloody or runny nose, coughing, chest discomfort, difficult or short breath, and wheezing due to constriction or excess fluid in the bronchial tubes. Skin contact with organophosphates may cause localized sweating and involuntary muscle contractions. Eye contact will cause bleeding, tears, pupil constriction, pain, and blurred vision. Symptoms of acute exposure to organophosphate or cholinesterase-inhibiting compounds may also include the following: dizziness, tremor, nausea, abdominal cramps, sweating, blurred vision, headache, numbness, tingling sensations, incoordination, difficulty breathing or respiratory depression, and slow heartbeat. Very high doses may result in unconsciousness, incontinence, and convulsions or fatality[12].
Chronic toxicity
Carcinogenic effectsThe National Cancer Institute performed carcinogenicity tests on fenthion that indicated that this insecticide might be a carcinogen in male mice. However, no carcinogenic effects were observed in other two-year feeding studies of rats and mice[13].
Reproductive effects-Single injections of 40 or 80 mg/kg of fenthion into the abdominal cavities of pregnant female mice caused poisoning in the developing fetuses, particularly when administered on days 10 through 12 of gestation. There were significantly more abnormalities in the offspring of female mice that had received 40 mg/kg on days 8 or 10 of pregnancy[14, 15].
Teratogenicity effects-Some reduction in fetal weight occurred, but no defects were found in mice that were given intraperitoneal doses of up to 80 mg/kg of fenthion in single day or 3-day periods during the period of gestation in which organs are formed[16].
References
Thomson, W. T. 1976. Insecticides, acaricides and avicides. Agricultural Chemicals, Book I. Fresno, CA: Thomson Publications.
EXTOXNET.[2003]. Pesticide information Profile for Fenthion. Cooperative Extension Offices of Cornell University, Michigan State University, Oregon State University, and University of California at Davis.
Meister, R.T.[ed.]. 1992. Farm Chemicals Handbook '92. Meister Publishing Company, Willoughby, OH.
Occupational Health Services, Inc. 1986. Material safety data sheet. Secaucus, NJ: OHS, Inc.
https://sitem.herts.ac.uk/aeru/ppdb/en/Reports/310.htm
Tucker, R. and D. G. Crabtree. 1970. Handbook of toxicity of pesticides to wildlife. U.S. Department of Agriculture, Fish and Wildlife Service. Bureau of Sport Fisheries and Wildlife.
McEwen, F. L. and G. R. Stephenson. 1979. The use and significance of pesticides in the environment. NY: John Wiley and Sons, Inc.
Hayes, W.J. and E.R. Laws[ed.]. 1990. Handbook of Pesticide Toxicology, Vol. 3, Classes of Pesticides. Academic Press, Inc., NY.
Sakaguchi, K., Akahori, F., Shirai, M., Masaoka, T., Arishima, K., & Kounenis, G.[1998]. Effect of combined fenthion and cimetidine use in rats on lethality, blood cholinesterase activities, and serum cholinesterase isoenzymes. Veterinary & Human Toxicology, 40(2], 77-82.
Macqueen, J, and D. Plaut. "A review of clinical applications and methods for cholinesterase. " American Journal of Medical Technology 39.7(1973]: 279-287.
Corbel, V., Stankiewicz, M., Pennetier, C., Fournier, D., Stojan, J., & Girard, E., et al.[2009]. Evidence for inhibition osnsect and mammalian nervous systems by the insect repellent deet. Bmc Biology, 10(1], 86-86.
Occupational Health Services, Inc. 1991[Sept. 16]. MSDS for Fenthion. OHS Inc., Secaucus, NJ.
National Cancer Institute. 1979. Bioassay of fenthion for possible carcinogenicity. Technical report series no. 103. U.S. Department of Health, Education, and Welfare. Publication No.[NIH] 791353. Washington, DC: U.S. Government Printing Office.
ACGIH. 1986. Documentation of threshold limit values and biological exposure indices. Cincinnati, OH: Publications Office, ACGIH.
Hayes, W. J. 1982. Pesticides studied in man. Baltimore, MD: Williams and Wilkins.
Shepard, T. H. 1986. Catalog of teratogenic agents. Fifth edition. Baltimore, MD: The Johns Hopkins University Press.
Reactivity Profile
Fenthion may react with strong reducing agents such as hydrides to generate highly toxic and flammable phosphine gas. Partial oxidation by oxidizing agents may result in the release of toxic phosphorus oxides.
Hazard
Toxic by ingestion, inhalation, and skin
absorption; use may be restricted, cholinesterase
inhibitor. Toxic by skin absorption; questionable
carcinogen.
Health Hazard
Fenthion is moderately toxic to mammals, and highly toxic to birds. Exposures to fenthion cause poisoning with symptoms among occupational workers as observed with organophosphate pesticide-induced toxicity. These include, but are not limited to, numbness, tingling sensations, incoordination, headache, dizziness, tremor, nausea, abdominal cramps, sweating, blurred vision, diffi culty breathing or respiratory depression, and slow heart beat. Very high doses may result in unconsciousness, incontinence, and convulsions or fatality. Reports have indicated that exposures to fenthion cause adverse effects on the central and peripheral nervous systems, and the heart of exposed workers.
Fire Hazard
Fenthion is probably combustible.
Trade name
B 29493?; BACID?; BAY 29493?;
BAYCID?; BAYER 29493?; BAYER 9007?; BAYER
S-1752?; BAYTEX?; ENTEX?; LEBAYCID?;
MPP?; MPP (pesticide) OMS 2?; PHENTHION?;
PILARTEX?; QUELETOX?; S 1752?; SPOTTON?;
SULFIDOPHOS?; TALODEX?; TIGUVON?
Potential Exposure
A potential danger to those involved
in the manufacture, formulation, or application of this agricultural chemical and pesticide; insecticide
Environmental Fate
Biological. From the first-order biotic and abiotic rate constants of fenthion in estuarine water and sediment/water systems, the estimated biodegradation half-lives were 22.4 and 3.9–14.5 days, respectively (Walker et al., 1988).Surface Water. In estuarine water, the half-life of fenthion was 4.6 days (Lacorte et al., 1995).
Plant. In plants, fenthion oxidizes to the mesulfenfos and sulfone which further degrades to the sulfone phosphate before undergoing hydrolysis (Hartley and Kidd, 1987).Photolytic. Fenthion was oxidized to the corresponding sulfoxide and trace amounts (<5% yield) of sulfone when sorbed on soil and exposed to sunlight. The photosensitized oxidation was probably due to the presence of singlet oxygen. The degradation rate was higher in soils containing the lowest organic carbon (Gohre and Miller, 1986).Chemical/Physical. Stable at temperatures below 210°C (Worthing and Hance, 1991). Emits very toxic fumes of phosphorus and sulfur oxides when heated to decomposition (Sax and Lewis, 1987; Lewis, 1990).
Metabolic pathway
The major route of fenthion metabolism is by oxidation to the sulfoxide
which has a higher insecticidal activity than the parent compound. The
subsequent oxidation of the sulfoxide to fenthion sulfone, the biological
activity of which is considerably lower, is slow in plants but of major
significance in animals. An additional route of bioactivation is through
oxidative desulfuration to form fenoxon and, in all, five oxidative
metabolites (fenthion sulfoxide, fenthon sulfone, fenoxon, fenoxon
sulfoxide and fenoxon sulfone) have been detected in most biological
systems. Hydrolysis, in contrast to most insecticidal phosphorothioates,
appears to proceed via direct hydrolysis of fenthion rather than its oxon.
The phenolic leaving group (3-methyl-4-thiomethylphenol) is identical to
that of fenamiphos and although no studies have described the fate of the
phenolic moiety for fenthion, it is likely that it will be metabolised by
similar routes to those described for fenamiphos.
Shipping
UN3018 Organophosphorus pesticides, liquid,
toxic, Hazard Class: 6.1; Labels: 6.1-Poisonous materials.
UN2810 Toxic liquids, organic, n.o.s., Hazard Class: 6.1;
Labels: 6.1-Poisonous materials, Technical Name Required.
Toxicity evaluation
Acute oral LD50 for rats: ca. 250 mg /kg
Degradation
Fenthion is stable in light, stable to acid and moderately stable to alkaline
conditions. The DT50s at pH 4, 7 and 9 were 223, 151 and 151 days
respectively (PM).
The effect of the cuticular waxes of fruit upon the photodegradation of
fenthion was studied by Cabras et al. (1997). Waxes were extracted with
acetone and the fenthion added to the solution. The wax plus fenthion
was applied as a film which was irradiated by natural sunlight. The
analysis of fenthion and its metabolites was by GLC-FID (Cabras and
Plumitallo, 1991). The potential metabolites synthesised were fenthion
sulfoxide (2), fenthion sulfone (3), fenoxon (4), fenoxon sulfoxide (5) and
fenoxon sulfone (6). Waxes from different fruits affected the decay rate,
with wax from oranges and nectarines increasing the rate of decomposition
but cuticular wax from olives retarding the rate. In all cases the
products of photodegradation were fentluon sulfoxide (2), which
steadily increased with time, and fenthion sulfone (3), which remained at
a low but detectable level throughout the experiment. Minelli et al. (1996)
exposed fenthion in glass jars to natural sunlight and analysed the photodegradation
products by GLC-FID. The major product was fenthion
sulfoxide (2) which very slowly degraded to the sulfone (3). This in turn
was even more slowly photo-oxidised to fenoxon sulfone (6). The routes
for the photodegradation of fenthion are shown in Scheme 1.
Incompatibilities
Incompatible with oxidizers (chlorates,
nitrates, peroxides, permanganates, perchlorates, chlorine,
bromine, fluorine, etc.); contact may cause fires or explosions. Keep away from alkaline materials, strong bases,
strong acids, oxoacids, epoxides, alkaline insecticides.
Organothiophosphates are susceptible to formation of
highly toxic and flammable phosphine gas in the presence
of strong reducing agents such as hydrideds and active
metals. Partial oxidation by oxidizing agents may result in
the release of toxic phosphorus oxides.
Waste Disposal
Hydrolysis and landfill for
small quantities; incineration with flue gas scrubbing for
large amounts. In accordance with 40CFR165, follow
recommendations for the disposal of pesticides and pesticide containers. Must be disposed properly by following
package label directions or by contacting your local or federal environmental control agency, or by contacting your
regional EPA office
Check Digit Verification of cas no
The CAS Registry Mumber 55-38-9 includes 5 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 2 digits, 5 and 5 respectively; the second part has 2 digits, 3 and 8 respectively.
Calculate Digit Verification of CAS Registry Number 55-38:
(4*5)+(3*5)+(2*3)+(1*8)=49
49 % 10 = 9
So 55-38-9 is a valid CAS Registry Number.
InChI:InChI=1/C10H15O3PS2/c1-8-7-9(5-6-10(8)15-3)13-14(11,12-2)16-4/h5-7H,1-4H3
55-38-9Relevant academic research and scientific papers
Oil-in-water emulsions
-
, (2008/06/13)
The present invention relates to oil-in-water emulsions containing 0.001 to 70% by weight of at least one active substance from the group consisting of phosphates, thiophosphates and/or carbamates, 0.001 to 30% by weight of one or more surfactant compounds from the group consisting of ethoxylated fatty amines or of phosphorylated fatty amine ethoxylates, and also, if desired, adjuvants and water to make up 100% by weight.
Agrochemical formulations for water surface application
-
, (2008/06/13)
New agrochemical formulations for application to the water of paddy fields, which formulations comprise A) at least one solid core material having an apparent specific density of less than 1 and a particle diameter within the range from about 300 μm to about 1,400 μm, and B) a coating layer comprising at least one biologically active compound, at least one substance having the ability to reduce the interfacial tension between water and air, at least one oily substance and, if appropriate, one or more additives, and the use of such agrochemical formulations for applying biologically active compounds to the water of paddy fields.
Oil-in-water emulsions
-
, (2008/06/13)
The present invention relates to oil-in-water emulsions containing 0.001-70% by weight of at least one active substance from the group consisting of phosphates, thiophosphates and/or carbamates, 0.001-30% by weight of one or more surfactant compounds from the group consisting of nonionic surfactant compounds or phosphorylated surfactant compounds or sulfated surfactant compounds or sulfonated surfactant compounds, and also, if desired, adjuvants, and, water to make up 100% by weight.
Oil-in-water emulsions
-
, (2008/06/13)
The present invention relates to oil-in-water emulsions comprising 0.001-70% by weight, preferably from 0.5 to 45% by weight, of at least one active substance from the class of the phosphates and/or carbamates, from 0.001-20% by weight, preferably from 0.1-10% by weight, of at least one salt of an aryl polyglycol ether phosphate of the formula I STR1 in which each R1, independently of the others, is hydrogen, C1 -C24 -alkyl, C5 -C15 -cycloalkyl, C8 -C24 -aryl or C6 -C24 -alkaryl, R2 is hydrogen, --O--C1 -C24 -alkyl, --O--C5 --C15 -cycloalkyl, --O--C6 -C18 -aryl or A, M is an alkali metal ion, alkaline earth metal ion or ammonium ion of the formula HN(R3)3, where each R3, independently of the others, is hydrogen, C1 -C4 -alkyl, C5 -C15 -cycloalkyl, C6 -C18 -aryl or a group of the formula --(CH2)z --OH in which z is a number from 1 to 10, x is a number from 0 to 80 and y is a number from 0 to 50, the sum of x and y not being zero, and, to make up to 100% by weight, water and, if desired, solvents and/or additives. These oil-in-water emulsions are preferably employed in agriculture and in horticulture, in the domestic and hygiene sectors and/or in the medical sector.
Process for preparing unsaturated ethers
-
, (2008/06/13)
A process for preparing unsaturated ethers of the formula (1) STR1 from acetals or ketal of the formula (2) STR2 is improved by heating the acetals or ketals at from 100° to 250° C. in a high-boiling, branched carboxylic acid and obtaining the unsaturated ether as a distillate. The process, which is insensitive to contaminants, gives the unsaturated ether in high yields.
Synthesis of [35S]phosphorothionate insecticides: The example of [35S]fenthion
Dias,Mornet,Kotoujansky
, p. 73 - 78 (2007/10/02)
A general method for the synthesis of [35S]phosphorothionates is proposed, based on the example of [35S]fenthion. This consists of reacting molecular 35S with the corresponding phosphites which are easily prepared from commercial precursors.
Oil-in-water emulsions and a process for their preparation and their use
-
, (2008/06/13)
Oil-in-water emulsions (microemulsions) containing 0.01-80% by weight of at least one agrochemical active substance of low water-solubility, one active substance for combating pests in the domestic and hygiene sector and/or one pharmacologically active substance, 1% to 30% by weight of an emulsifier mixture of non, ionic and anionic compounds and at least one alkylarylsulfonic acid salt, as defined in the description, as well as water and, if appropriate, 1% to 30% by weight of at least one solvent of low water-miscibility and/or one solubilizer, and if appropriate 0.05% to 15% by weight of additives, the sum of the components in each case being 100% by weight, a process for the preparation of these aqueous microemulsions and their use.
Biocidal macroemulsions containing polyvinyl alcohol
-
, (2008/06/13)
The present invention relates to new macroemulsions which contain 0.001 to 60 percent by weight of at least one active compound from the class comprising the phosphates and/or carbamates, 0 to 50 percent by weight of aromatic diluents, 0.001 to 20 percent by weight of polyvinyl alcohol having a mean molecular weight of between 5,000 and 150,000 and a content of acetate groups of between 2 and 30 mol %, and/or 0.001 to 20 percent by weight of a nonlphenol/propylene oxide/ethylene oxide adduct of the formula STR1 in which X represents integers from 10 to 50 and Y represents integers from 15 to 65, and/or 0.001 to 20 percent by weight of ethylene oxide/propylene oxide/ethylene oxide block copolymers having a mean molecular weight of between 2,000 and 8,000 and HLB values of between 8 and 30, and water and, if appropriate, additives, and in which the oil phase is dispersed in the aqueous phase in the form of droplets having a mean particle diameter of 0.1 to 3.0 μm.
Oil-in-water emulsions, and their use
-
, (2008/06/13)
Novel oil-in-water emulsions, which contain (a) 0.1 to 80% by weight of at least one sparingly water-soluble active compound (as herein defined) selected from agrochemical active compounds, active compounds for combating pests in the domestic field and hygiene field and/or pharmacologically active compounds, (b) 1 to 20% by weight of at least one alkylaryl polyglycol ether of the general formula STR1 wherein R1 represents a hydrogen atom or an alkyl group having 1 to 16 carbon atoms, R3 represents a hydrogen atom or a methyl group, m is 1, 2 or 3, and n is an integer from 10 to 50, if appropriate in a mixture with an alkylarylsulphonic acid salt of the general formula STR2 wherein R3 represents an alkyl group having 8 to 35 carbon atoms and Me≈ represents an alkali metal cation, an equivalent of an alkaline earth metal cation or a cation of the general formula STR3 wherein R', R", R'" and RIV independently of one another represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms or a hydroxyalkyl group having 1 to 4 carbon atoms, (c) water, (d) if necessary, 1 to 30% by weight of at least one poorly water-miscible organic solvent and/or a solubilizer, and (e) if appropriate 0.05 to 15% by weight of one or more additives, the sum of the components being 100% by weight in each case, a process for the preparation of these emulsions and their use in the field appropriate to the active compound.
