| Chemical Abstract Number (CAS #) |
2032657
|
|---|
| Synonyms | Methiocarb |
|---|
Mercaptodimethur | Phenol, 3,5-dimethyl-4-(methylthio)-, methylcarbamate | Carbamic acid, methyl-, 4-(methylthio)-3,5-xylyl ester | Mesurol |
| Analytical Methods |
EPA Method 531.1 |
|---|
EPA Method 632 |
| Molecular Formula | C11H15NO2S |
|---|
| Use | ACARICIDE; MOLLUSCICIDE
Used to control slugs & snails in a wide range of agricultural situations. Broad-range control of
Lepidoptera, Coleoptera, Diptera, & Homoptera (incl soil insects), & spider mites in pome fruit,
stone fruit, strawberries, hops, potatoes, beet, maize, oilseed rape, vegetables, & ornamentals.
Used as seed treatment for control of frit flies on maize, flea beetles on oilseed rape, & leaf miners
on beet; & also acts as a bird repellent.
Slug & snail control in & around home flower gardens & ornamentals. Controls cherry maggot on
cherries; blueberry maggot on blueberries; yellow jackets on grapes. Bird repellency on cherries.
Research indicates excellent repellency on grapes, rice, & sorghum. Registered in several USA
states for bird repellency on blueberries, cherries. In several countries bird repellency on corn.
Foliar sprays and seed treatments provide effective rodent control from newly sown seed and
maturing crops
IT IS PARTICULARLY EFFECTIVE FOR CONTROL OF MITES, INCLUDING
PHOSPHATE RESISTANT STRAINS, AT RELATIVELY LOW RATES
|
|---|
| Consumption Patterns | Citrus, 53.2%; Rice, 18.8%; most of remainder applied to artichokes, cherries and
ornamentals (1984). California use, calculated from table
|
|---|
| Apparent Color | WHITE CRYSTALLINE POWDER
|
|---|
| Odor | MILD ODOR
|
|---|
| Melting Point | 119 deg C
|
|---|
| Molecular Weight | 225.3
|
|---|
| Sensitivity Data | EXPOSURE TO HUMAN FOREARMS CAUSED SKIN IRRITATION AFTER 24 HR.
Inhalation may cause irritation of the mucous membranes.
|
|---|
| Environmental Impact | Methiocarb is released directly to the environment in its application as a pesticide. If
released to soil, methiocarb may hydrolyze quite rapidly in the presence of moisture. It was found
to be highly mobile in a silt loam soil (Koc of 70), but estimation of Koc based on water solubility
and log Kow (Koc of 672-923) predict low soil mobility. Sensitized photolysis may occur on plant
and soil surfaces exposed to sunlight. If released to water, methiocarb may be expected to
hydrolyze quite rapidly as evidenced by its complete hydrolysis to
4-methylthio-3,5-dimethylphenol and methyl carbamic acid within one week in a natural sample.
Sensitized photolysis in natural waters may be possible since rotenone and chloroplasts have been
shown to photosensitize the photolysis of methiocarb. Aquatic volatilization and bioconcentration
are not expected to be significant. If released to the atmosphere, methiocarb may exist in both the
vapor- and the adsorbed-phase, although the adsorbed-phase may be dominant. The half-life for
the vapor-phase reaction of methiocarb with photochemically produced hydroxyl radicals has been
estimated to be 7.92 hr. Adsorbed methiocarb will be subject to wet and dry deposition.
Occupational exposure to methiocarb can occur through inhalation and dermal routes related to
its use as a pesticide.
|
|---|
| Environmental Fate | TERRESTRIAL FATE: Since methiocarb has been shown to completely hydrolyze in a
natural water solution within one week, it may be expected to hydrolyze quite rapidly in moist
soil. Methiocarb was found to be highly mobile in a silt loam soil (Koc of 70), although estimation
of Koc based on water solubility and log Kow (Koc of 672-923) predict low soil mobility.
Leaching may not be important, regardless of Koc, since methiocarb may hydrolyze quite rapidly.
Sensitized photolysis may occur on plant and soil surfaces exposed to sunlight.
AQUATIC FATE: Methiocarb may be expected to hydrolyze quite rapidly in environmental
waters as evidenced by its complete hydrolysis to 4-methylthio-3,5-dimethylphenol and methyl
carbamic acid within one week in a natural water sample). Sensitized photolysis in natural waters
may be possible since rotenone and chloroplasts have been shown to photosensitize the photolysis
of methiocarb. Aquatic volatilization and bioconcentration are not expected to be significant.
ATMOSPHERIC FATE: Based on a vapor pressure of 0.0001125 mmHg at 60 deg C ,
methiocarb may be expected to exist in both the vapor-phase and adsorbed to particulate matter in
the atmosphere, although the adsorbed-phase may be dominant . The half-life for the
vapor-phase reaction of methiocarb with photochemically produced hydroxyl radicals has been
estimated to be 7.92 hr. Adsorbed methiocarb will be subject to wet and dry deposition.
|
|---|
