16752-77-5 Usage
Uses
Used in Agriculture:
Methomyl is used as an insecticide and acaricide for controlling a wide range of pests, including ticks and spiders, in various crops such as vegetables, fruits, field crops, tobacco, cotton, alfalfa, soybeans, and corn. It is effective against organophosphorus-resistant pests and is used for foliar treatment, as well as in and around poultry houses and dairies.
Methomyl is used as a contact insecticide for killing target insects upon direct contact and as a systemic insecticide, causing overall "systemic" poisoning in target insects after being absorbed and transported throughout the pests that feed on treated plants. It is capable of being absorbed by plants without being phytotoxic or harmful to the plant.
Used in Insect Control:
Methomyl is used as a foliar spray to control pests in field crops, stables, and poultry houses, as well as in glasshouses on ornamentals and vegetables. It has been reported to be effective in cases involving chrysanthemum growers and workers in plant nurseries.
Used in Fly Control:
Methomyl is also used as fly bait to control flies in various settings, including agricultural and livestock areas.
Air & Water Reactions
Water soluble.
Reactivity Profile
Methomyl is a carbamate ester. Carbamates are chemically similar to, but more reactive than amides. Like amides they form polymers such as polyurethane resins. Carbamates are incompatible with strong acids and bases, and especially incompatible with strong reducing agents such as hydrides. Flammable gaseous hydrogen is produced by the combination of active metals or nitrides with carbamates. Strongly oxidizing acids, peroxides, and hydroperoxides are incompatible with carbamates.
Hazard
Toxic by ingestion. Acetyl cholinesterase
inhibitor, male reproductive damage, and hematologic effects. Questionable carcinogen.
Health Hazard
Acetamidic acid (methomyl) is potentially a highly poisonous material in humans.
Exposures to acetamidic acid (methomyl) cause adverse health effects. It is highly toxic
and causes inhibition of cholinesterase activity. The symptoms of toxicity include, but
are not limited to, weakness, lack of appetite, blurred vision, pupillary constriction, cor-
neal injury, headache, nausea, abdominal cramps, burning sensation, coughing, wheez-
ing, laryngitis, shortness of breath, and vomiting. It may be harmful if absorbed through
the skin of the mucous membranes and upper upper respiratory tract and cause chest
discomfort, constriction of pupils, sweating, muscle tremors, and decreased pulse. After
severe poisoning, occupational workers show symptoms of twitching, giddiness, confu-
sion, muscle incoordination, heart irregularities, loss of refl
exes, slurred speech, paralysis
of the muscles of the respiratory system, and death. The target organs of methomyl toxic-
ity include nerves, cardiovascular system, liver, and kidneys.
Health Hazard
Methomyl has high oral toxicity, moderate inhalation toxicity and low skin toxicity. The probable oral lethal dose for humans is between 7 drops and 1 teaspoon for a 150 pound adult. Death is due to respiratory arrest.
Health Hazard
Extremely toxic by oral route; moderatelytoxic by inhalation; exhibits acute, delayed,and chronic effects; cholinesterase inhibitor;symptoms are those of phosphate — or carbamate esters — the major signs of whichare increased salivation, lacrimation, spontaneous urination, blurred vision, pinpointpupils, tremor, twitching of muscle and lossof coordination; confusion, convulsions, andcoma may occur as well; other signs ofpoisoning include nausea, vomiting, cramps,diarrhea, slow heart rate, shortness of breath,and pulmonary edema (U.S. EPA 1988);death may result from respiratory arrest(Gosselin et al. 1984); the probable lethaldose from ingestion in adult human could be0.5–2 g; oral lethal dose in dog 30 mg/kg,and monkey 40 mg/kg; toxic effects fromskin absorption low; listed as extremely hazardous substance by the U.S. EPA.LD50 oral (mouse): 10 mg/kgLD50 oral (rat): 17 mg/kgLD50 inhalation (rat): 77 ppmTsai et al. (2003) have reported a caseof outbreak of food poisoning at a seafoodrestaurant in Taiwan. High levels of methomyl were found in leafy-vegetables stir-friedwith crab claws (380 ppm) and fried mussels (1113 ppm). The median latency frombeginning eating to first symptoms was5-minutes. The clinical symptoms were general weakness, ataxia, dizziness, vomiting,sweating, floating sensation, headache, dyspnea, and blurred vision..
Fire Hazard
When heated to decomposition, Methomyl emits very toxic fumes of nitrogen oxides and sulfur oxides. Do not subject liquid formulations to temperatures below 32F.
Flammability and Explosibility
Notclassified
Trade name
ACINATE?; AGRINATE?; CIMETLE?;
DuPont
TM 1179?; FRAM FLY KILL?; FLYTEK?;
IMPROVED BLUE MALRIN SUGAR BAIT?;
IMPROVED GOLDEN MALRIN BAIT?; INSECTICIDE
1179?; KIPSIN?; KUIK?; LANNATE?; LANNOX?;
LANOX 90?; LANOX 216?; METHOMEX?;
METHOMYL? 20SC; MEMILENE?; METHAVIN?;
NU-BAIT II?; NUDRIN?; PILLARMATE?;
RENTOKILL?; RENTOKIL FRAM FLY BAIT?;
RIDECT?; SD 14999?; SOREX GOLDEN FLY BAIT?;
WL 18236?
Contact allergens
Methomyl is a pesticide agent, a carbamate insecticide with anticholinesterase activity. This mixture of two stereoisomers is used as a foliar spray to control field crops, in stables and poultry houses, and in glasshouses on ornamentals and vegetables, or in flypapers. Cases were reported in chrysanthemum growers and in two women working in a plant nursery
Safety Profile
Poison by ingestion,
inhalation, and subcutaneous routes. Mildly
toxic by skin contact. Wen heated to
decomposition it emits very toxic fumes of
NOx and SOx.
Potential Exposure
Methomyl is a broad-spectrum insecticide used as insecticide in many vegetables, field crops;
certain fruit crops; and ornamentals.
Incompatibilities: Keep away from strong bases, strong oxidizers. Heat causes decomposition forming toxic and irritating fumes including nitrogen oxides; sulfur oxides;
hydrogen cyanide; methylisocyanate
Environmental Fate
Biological. From the first-order biotic and abiotic rate constants of methomyl in
estuarine water and sediment/water systems, the estimated biodegradation half-lives were
75–165 and 39–134 days, respectively (Walker et al., 1988).Soil. Harvey and Pease (1973) reported that methomyl dissipated rapidly in fine sand
and loamy sand soils. One month following application to a Delaware soil, 1.8% of the
applied dosage was recovered and after 1 year, methomyl was not detected. TGroundwater. According to the U.S. EPA (1986) methomyl has a high potential to
leach to groundwater.Plant. The reported half-lives of methomyl on cotton plants, mint plants and Bermuda
grass were 0.4–8.5, 0.8–1.2 and 2.5 days, respectively (Willis and McDowell, 1987).Chemical/Physical. Emits toxic fumes of nitrogen and sulfur oxides when heated to
decomposition (Sax and Lewis, 1987; Lewis, 1990).
storage
Acetamidic acid (methomyl) should be kept stored in a sealed container in a cool
(below 0
°
C), dry, area with adequate ventilation. The chemical should be kept away
from incompatible chemical substances, strong oxidizing agents, strong bases, other
pesticides, and food or feed.
Shipping
UN2757 Carbamate pesticides, solid, toxic,
Hazard Class: 6.1; Labels: 6.1-Poisonous materials.
UN2811 Toxic solids, organic, n.o.s., Hazard Class: 6.1;
Labels: 6.1-Poisonous materials, Technical Name Required
Waste Disposal
Consult with environmental
regulatory agencies for guidance on acceptable disposal
practices. Generators of waste containing this contaminant (≥100 kg/mo) must conform to EPA regulations
governing storage, transportation, treatment, and waste
disposal. Alkaline hydrolysis leads to complete degradation to nontoxic products. May be dissolved in water
and sprayed into a furnace with effluent gas scrubbing
also. 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.
Precautions
Occupational workers should avoid contact of acetamidic acid (methomyl) with the skin,
eyes, or clothing, and avoid exposures to vapor or mist. Workers should be careful when
storing and/or disposing of acetamidic acid, avoid the dust contaminating water, food,
or feed by storage or disposal. Workers should use respiratory protection: Government approved respirator. Hand Protection: Compatible chemical-resistant gloves. Eye
Protection: Chemical safety goggles.chemical safety goggles.
Check Digit Verification of cas no
The CAS Registry Mumber 16752-77-5 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 1,6,7,5 and 2 respectively; the second part has 2 digits, 7 and 7 respectively.
Calculate Digit Verification of CAS Registry Number 16752-77:
(7*1)+(6*6)+(5*7)+(4*5)+(3*2)+(2*7)+(1*7)=125
125 % 10 = 5
So 16752-77-5 is a valid CAS Registry Number.
InChI:InChI=1/C5H10N2O2S/c1-4(10-3)7-9-5(8)6-2/h1-3H3,(H,6,8)/b7-4-
16752-77-5Relevant articles and documents
Preparation method of methomyl
-
Paragraph 0011; 0026-0046, (2020/07/24)
The invention discloses a preparation method of methomyl. Methylthio acetaldoxime is used as a raw material and reacts with methyl isocyanate in water under the action of a phase transfer catalyst, the temperature is raised to 50-60 DEG C after the reaction is finished, cooling crystallization and filtration are performed after the material is completely dissolved, filtrate and a filter cake are obtained, the filtrate is extracted with an organic solvent, desolvation is then carried out, desolventized solids and the filter cake are combined and dried, and a methomyl product is obtained. The preparation method has the advantages of high yield, low cost, simplicity and convenience in operation and the like.
Pyrazole oxime derivatives and compositions
-
, (2008/06/13)
A pyrazole oxime derivative represented by the general formula (I) which is useful as an insecticide and fungicide, STR1 wherein the structural elements are defined in the specification, and the method of controlling said pests. The compounds represented by the general formula (I) can be synthesized by the methods disclosed in the specification.
Process for the preparation of carbamates of N-hydroxythioimidates
-
, (2008/06/13)
An improved process for converting N-hydroxythioimidates to N-(methylcarbamoyloxy)-thioimidates by reaction with methylcarbamoyl chloride at pH above 10 in a two-phase reaction medium: water and a water-immiscible organic solvent.
