22224-92-6 Usage
Description
Fenamiphos is a colorless crystalline substance or a tan, waxy solid that is non-corrosive to metals and breaks down readily in strong acids and bases. It is used as a nematicide and an insecticide for a wide variety of field, vegetable, and fruit crops.
Uses
Used in Agricultural Industry:
Fenamiphos is used as a nematicide and insecticide for controlling nematodes (roundworms) and other pests such as mites and sucking insects in crops. It is effective against a wide range of nematode pests that live as parasites on the outside or inside of plants, as well as those associated with cyst and root-knot formations. Fenamiphos is absorbed by roots and distributed throughout the plant, blocking the enzyme acetylcholinesterase in the target pests.
Fenamiphos is used on a variety of plants, including tobacco, turf, bananas, pineapples, citrus and other fruit vines, some vegetables, and grains. It is a Restricted Use Pesticide (RUP) due to its high acute toxicity and toxicity to wildlife. The US EPA has grouped fenamiphos as an RUP, and reports have indicated that the manufacture and sale of fenamiphos are to be phased out by 2007-2008.
References
https://pubchem.ncbi.nlm.nih.gov/compound/fenamiphos#section=Top
http://extoxnet.orst.edu/pips/fenamiph.htm
Air & Water Reactions
Fenamiphos is hydrolyzed by strong acids and strong alkalis.
Reactivity Profile
Organothiophosphates, such as Fenamiphos, are susceptible to formation of highly toxic and flammable phosphine gas in the presence of strong reducing agents such as hydrides. Partial oxidation by oxidizing agents may result in the release of toxic phosphorus oxides.
Hazard
Toxic by inhalation and skin contact. Questionable carcinogen.
Health Hazard
Occupational exposures to fenamiphos cause severe toxicity and adverse health effects. It inhibits the activity of the cholinesterase enzyme in humans, leading to over stimulation of the nervous system. The symptoms of poisoning include, but are not restricted to, nausea, dizziness, confusion, impaired memory, disorientation, severe depression, irritability, headache, speech diffi culties, delayed reaction times, nightmares, sleepwalking, and drowsiness or insomnia. Very high exposures, such as accidental ingestion and/or major spillage, cause respiratory paralysis and death. Laboratory studies have indicated that the teratogenic effects of fenamiphos occurred only at levels that caused overt maternal toxicity and are likely indirect consequences of this toxicity. Other studies have indicated that fenamiphos is non-mutagenic and also have no evidence suggesting that fenamiphos is carcinogenic to animals and humans.
Health Hazard
Fenamiphos is highly toxic orally, by inhalation, and by absorption through the skin. (Non-Specific -- Parathion) Death may occur from respiratory failure.
Fire Hazard
(Non-Specific -- Organophosphorus Pesticide, n.o.s.) Container may explode in heat of fire. Fire and runoff from fire control water may produce irritating or poisonous gases. Emits toxic fumes of nitrogen oxides, phosphorus oxides, and sulfur oxides when heated to decomposition.
Flammability and Explosibility
Notclassified
Trade name
BAY 68138?; Bayer 68138?;
NEMACUR?; NEMACURP?
Safety Profile
Poison by ingestion,
inhalation, and skin contact. When heated to
decomposition it emits very toxic fumes of
NOx, POx, and SOx.
Environmental Fate
Soil. Oxidizes in soil to the corresponding sulfone and sulfoxide (Lee et al., 1986). Fenamiphos rapidly degraded in Arredondo soil to fenamiphos sulfone and at the sametime to the corresponding phenol. The half-life in this soil is 38–67 days (Ou and Rao, 1986).
Surface Water. In estuarine water, the half-life of fenamiphos was 1.80 days (Lacorte et al., 1995).Chemical/Physical. Emits toxic fumes of phosphorus, nitrogen and sulfur oxides when heated to decomposition (Sax and Lewis, 1987; Lewis, 1990).
Metabolic pathway
Fenamiphos is an effective nematicide with both protectant and curative
action. Free-living, ecto- and endo-parasitic, cyst-forming and root knot
nematodes are controlled. Foliarly applied compound is translocated in
plants to the roots and there is evidence that both translocation and optimum
anti-cholinesterase and nematicide activity require oxidation of the
thiomethyl group to the sulfoxide or the sulfone. These thiooxidation
products are much more easily hydrolysed than fenamiphos itself and
hydrolytic degradation in the environment most probably occurs via the
formation of these intermediates.
Metabolism
The oxidation of the thiomethyl group to the sulfoxide
and sulfone is required for both translocation and
nematicidal activity in plants. The oxidation products are
more susceptible to hydrolysis than fenamiphos itself.
In mammals, orally administered fenamiphos is rapidly
metabolized to the sulfoxide and sulfone, followed by subsequent hydrolysis, conjugation, and excretion in the
urine. N-Dealkylation also occurs. The DT50 in soils
is several weeks; the major degradation products are
fenamiphos sulfoxide and sulfone and their phenols.
Toxicity evaluation
The acute oral LD50 for rats is about 6 mg/kg.
Inhalation LC50 (4 h) for rats is about 0.12 mg/L air.
NOEL (2 yr) for rats is 1 mg/kg diet (0.05 mg/kg/d). ADI is
0.5 μg/kg b.w.
Degradation
For an organophosphorus compound, fenamiphos is relatively stable to
hydrolysis. The DT50s at pH values 4, 7 and 8 were 1 year, 8 years and
3 years respectively (PM). Fenamiphos was fairly stable in phosphate
buffers at pH values 5 and 7 at 30-50 °C in the dark but in natural pond
water containing silt the DT50 was about 5 days. In pH 9 buffer the DT50
was about 13 days. Under basic conditions the main product of hydrolysis
was the phenol (2) (Waggoner and Khasawinah, 1974).
Walia and Dureja (1990) have studied the photolysis of fenamiphos in
methanol solution irradiated by an unfiltered high pressure mercury
lamp. The photosensitiser and singlet oxygen generator Rose Bengal was
also included in one of the experiments. Analysis and characterisation
were carried out by TLC, MS and 1H NMR. In the presence of Rose Bengal
the major product was fenamiphos sulfoxide (3). Since singlet oxygen is
generated on soil surfaces and in silty water this experiment may be of
relevance to the activation of fenamiphos in the environment. In the
absence of a photosensitiser, the compound was cleaved to produce the
phenol, 3-methyl-4-(methylthio)phenol (2) and its O-methylated derivative
(not shown in Scheme 1), indicative of the involvement of methanol
in the reaction. In an experiment which more closely mimicked the conditions
for photodegradation in the environment, Barcelo et al. (1993)
examined the photolysis of fenamiphos in water containing 24% methanol
irradiated by a xenon arc (suntest) lamp. Metabolites were analysed
and characterised by HPLC, thermospray MS and W (diode array)
spectra. Fenamiphos was photodegraded to the extent of 98% after 90 min
of irradiation. The main degradation product identified was fenamiphos
sulfoxide (3). Products of the hydrolysis and photolysis of fenamiphos are
shown in Scheme 1.
Check Digit Verification of cas no
The CAS Registry Mumber 22224-92-6 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 2,2,2,2 and 4 respectively; the second part has 2 digits, 9 and 2 respectively.
Calculate Digit Verification of CAS Registry Number 22224-92:
(7*2)+(6*2)+(5*2)+(4*2)+(3*4)+(2*9)+(1*2)=76
76 % 10 = 6
So 22224-92-6 is a valid CAS Registry Number.
InChI:InChI=1/C13H22NO3PS/c1-6-16-18(15,14-10(2)3)17-12-7-8-13(19-5)11(4)9-12/h7-10H,6H2,1-5H3,(H,14,15)
22224-92-6Relevant articles and documents
Compositions against wood-destroying insects
-
, (2008/06/13)
The present invention relates to long-acting compositions against wood-destroying insects, characterized in that they contain a) insecticidally active compounds, b) organic natural compounds or organic synthetic compounds or mixtures thereof as carrier material, c) optionally microbicidally active compounds, d) optionally attractants or development-inhibitory compounds for insects, e) and optionally formulation auxiliaries.
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.
