Methomyl is a carbamate insecticide introduced in 1966. It is highly toxic to humans, livestock, pets, and wildlife.^[3] The EU imposed a pesticide residue limit of 0,01 mg/kg for all fruit and vegetables.^[4]

Quick Facts Names, Identifiers ...

Methomyl^[1]

(E)-Methomyl
(Z)-Methomyl
Names
IUPAC name (E,Z)-methyl N-{[(methylamino)carbonyl]oxy}ethanimidothioate
Other names Lannate, Mesomile, Methomex, Nudrin
Identifiers
CAS Number	16752-77-5 Y
3D model (JSmol)	Interactive image
ChEBI	CHEBI:6835 N
ChEMBL	ChEMBL552761 N
ChemSpider	3966 N
ECHA InfoCard	100.037.089
PubChem CID	5353758
CompTox Dashboard (EPA)	DTXSID1022267
InChI InChI=1S/C5H10N2O2S/c1-4(10-3)7-9-5(8)6-2/h1-3H3,(H,6,8) N Key: UHXUZOCRWCRNSJ-UHFFFAOYSA-N N InChI=1/C5H10N2O2S/c1-4(10-3)7-9-5(8)6-2/h1-3H3,(H,6,8) Key: UHXUZOCRWCRNSJ-UHFFFAOYAU
SMILES CNC(=O)ON=C(C)SC
Properties
Chemical formula	C5H10N2O2S
Molar mass	162.20
Appearance	White crystalline solid[2]
Odor	Slight, sulfur-like[2]
Density	1.2946 g/cm3
Melting point	78 to 79 °C (172 to 174 °F; 351 to 352 K)
Solubility in water	58 g/L
Vapor pressure	0.00005 mmHg (25°C)[2]
Hazards
Flash point	Noncombustible[2]
NIOSH (US health exposure limits):
PEL (Permissible)	none[2]
REL (Recommended)	TWA 2.5 mg/m3[2]
IDLH (Immediate danger)	N.D.[2]
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). N verify (what is YN ?) Infobox references

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Methomyl is a common active ingredient in commercial fly bait, for which the label instructions in the United States warn that "It is a violation of Federal Law to use this product in a manner inconsistent with its labeling." "Off-label" uses and other uses not specifically targeted at problem insects are illegal, dangerous, and ill-advised.^[5][6]

Methomyl is a broad-spectrum insecticide that is used to kill insect pests.^[7] Methomyl is registered for commercial/professional use under certain conditions on sites including field, vegetable, and orchard crops; turf (sod farms only); livestock quarters; commercial premises; and refuse containers. Products containing 1% Methomyl are available to the general public for retail sale, but more potent formulations are classified as restricted-use pesticides: not registered for homeowner or non-professional application.^[7] However, Heliothis virescens developed a resistance to methomyl within 5 years.^[8] Other species like Helicoverpa assulta also developed resistance after exposure.^[9]

In acute toxicity testing, methomyl is placed in EPA Toxicity Category I (the highest toxicity category out of four) via the oral route and in eye irritation studies.^[7] It is in lower Toxicity Categories for inhalation (Category II), acute dermal effects (Category III), and acute skin irritation (Category IV). Methomyl is not likely to be a carcinogen (EPA carcinogen Category E).^[7]

Methomyl has low persistence in the soil environment, with a reported half-life of approximately 14 days.^[10] Because of its high solubility in water, and low affinity for soil binding methomyl may have potential for groundwater contamination.^[7][11] The estimated aqueous half-life for the insecticide is 6 days in surface water and over 25 weeks in groundwater.^[11]

First prepare thioester:

Second prepare oxime from thioester:

Third prepare product from methyl isocyanate and the finished oxime:

Common names for methomyl include metomil and mesomile. Trade names include Acinate, Agrinate, DuPont 1179, Flytek, Kipsin, Lannate, Lanox, Memilene, Methavin, Methomex, Nudrin, NuBait, Pillarmate and SD 14999 ^[11]