| Chemical Abstract Number (CAS #) |
2008415
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| Synonyms | Butylate |
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Carbamothioic acid, bis(2-methylpropyl)-, S-ethyl ester | S-Ethyl diisobutylthiocarbamate | Anelda | Diisocarb | Sutan |
| Analytical Method |
EPA Method 634 |
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| Molecular Formula | C11H23NOS |
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| Use | A SELECTIVE HERBICIDE WELL TOLERATED BY CORN. EFFECTIVE
AGAINST ANNUAL GRASS WEED SPECIES SUCH AS BARNYARD GRASS
CRABGRASS FOXTAILS & GOOSEGRASS IT IS ALSO EFFECTIVE AGAINST
NUTSEDGES BERMUDAGRASS SEEDLINGS & JOHNSONGRASS SEEDLINGS .
Control of annual grass weeds in maize, by pre-plant soil incorporation. Some broad-leaved
weeds will also be controlled.
Butylate is a selective herbicide which will provide effective preemergence control of
perennials from seed such as quackgrass . Broadleaf weeds such as lambsquarters, redroot
pigweed, purslane, annual morningglory, Florida purslane, and velvetleaf will be controlled if
application is made when conditions are favorable for germination.
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| Apparent Color | Clear liquid; Amber liquid
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| Odor | AROMATIC ODOR
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| Boiling Point | 138 DEG C @ 21.5 MM HG
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| Molecular Weight | 217.41
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| Density | 0.9402 @ 25 DEG C/25 DEG C
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| Environmental Impact | Sutan's use as a herbicide releases the compound directly to the environment through
applications in emulsifiable formulations, sprays or other routes of application. If released to the
atmosphere, sutan will degrade rapidly in the vapor phase by reaction with photochemically
produced hydroxyl radicals (half-life of about 12 hr). Its detection in rainwater samples indicates
that physical removal from air via wet deposition can occur. If released to soil, sutan will dissipate
primarily through microbial degradation and volatilization. Immediate soil incorporation can
dramatically reduce volatilization. Soils previously exposed to sutan usually degrade it faster than
soils having no prior exposure due to microbial acclimation. Sutan has low to medium mobility in
soil. Various persistence studies indicate that sutan can have a soil half-life ranging from about
one to five weeks. Occupational exposure to sutan occurs through dermal contact and inhalation
of sprays, especially to workers applying the compound as a herbicide.
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| Environmental Fate | TERRESTRIAL FATE: BUTYLATE DEGRADES TO SULFOXIDE IN SOIL.
Duration of residual activity in soil is about 4 months.
TERRESTRIAL FATE: The important dissipation processes for sutan in soil are biodegradation
and surface volatilization. Microbial breakdown plays an important role in the degradation of
sutan in soil(1,4). Various field and laboratory studies have demonstrated that sutan degrades
more rapidly in soils previously exposed to sutan(2-3) indicating that microbial acclimation can
enhance soil dissipation. In one microagroecosystem study , delaying soil incorporation
of sutan (applied as an emsulifiable concentrate) for 24 hrs resulted in a 65% loss by
volatilization ; immediate soil incorporation dramatically reduces surface vaporization . Soil
Koc values of 185-400(6-7) indicate medium soil mobility, although the results of a field study(8)
suggest low mobility.
TERRESTRIAL FATE: The US Dept of Agric's Pesticide Properties Database lists a soil
half-life of 13 days for sutan . The soil half-lives under crop growing conditions has been
reported to range from 1.5 to 3 weeks . In a microagroecosystem study, soil incorporated sutan
(emulsifiable concentrate) had an initial dissipation half-life of about 10 days with an 80%
dissipation rate after 55 days ; when applied in a microencapsulated form, 44% dissipated after
55 days . In an Italian field study using a silt loam and a clay loam soil, half-lives of 11-12 days
were observed in the 0-10 cm soil layer while half-lives of 31-36 days were observed in the 20-30
cm soil layer . Sutan half-lives of approximately 8-28 days were observed in various laboratory
and field studies ; degradation rates were faster in soils previously treated with sutan or other
thiocarbamate herbicides . In a field study using a soil previously exposed to sutan, the initial
soil degradation half-life was approximately 10 days(6).
AQUATIC FATE: Since microbial degradation plays an important role in sutan's degradation in
soil(1-2), it may be important in natural waters having high microbial content. In contrast to soil
volatilization, volatilization from water may not be very important; the volatilization half-life from
a model environmental pond (2 meters deep) can be estimated to be about 71 days(3,SRC).
ATMOSPHERIC FATE: Based upon a reported vapor pressure of 1.3X10-3 mm Hg at 20 deg
C , sutan will exist primarily in the vapor phase in the ambient atmosphere(2,SRC). It will
degrade rapidly in the vapor phase by reaction with photochemically produced hydroxyl radicals
with an estimated half-life of about 12 hr(3,SRC). Particulate phase sutan and aerosols released to
air during applications of sutan herbicide will be removed from air physically by dry and wet
deposition. Sutan's detection in rainwater samples indicates that wet deposition occurs in
the environment.
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| Drinking Water Impact | GROUNDWATER: Sutan was not detected in 216 samples of Oregon well water; 20%
of wells sampled in Wisconsin tested positive for Sutan with a maximum reported concn of 4.9
ug/l (detection limit 0.2-0.01 ug/l) ; 21% of 56 wells sampled in the vicinity of an agrichemical
dealer facility in Illinois - facility wells - 28 ug/l max, 11.3 ug/l mean; not detected in neighboring
wells . It has also been detected, not quantified in groundwater and water supplies in Iowa,
Texas, and Georgia . In the early 1980's, 1174 community wells and 617 private wells were
sampled in Wisconsin; sutan was detected, not quantified in one well . Of the 73 wells sampled
in Nebraska during the mid 1970's through the late 1980's, sutan was not detected (detection limit
0.01-0.05 ppb .
GROUNDWATER: Sutan was detected at a concn between 0.1-1.0 ug/l in 1 of 237 wells,
contaminated as a result of a spill, sampled in Ontario, Canada between 1969 and 1978 ;
detected (detection limit 1.0 ug/l) in 1 of 359 wells between 1979 and 1984 which were
contaminated as a result of a spill ; detected in wells from 4 of 91 farms (detection limit 1.0 ug/l
in November and December 1984 in Southern Ontario, Canada . Sutan was not detected
(detection limit <10 ppb) in new drinking water wells sunk in the province of Bergamo, Northern
Italy .
SURFACE WATER: Sutan was reported to be present (not quantified) in the Lake Erie
ecosystem - Cuyahoga River, Sadusky River, Maumee River, and the River Raisin . Sutan
concn in 7 Lake Erie tributaries draining agricultural watersheds monitored from April 1983 to
December 1991 (detection limit 0.05 ug/l) ranged from 0.24-5.73 ug/l . Sutan was not detected
(detection limit 0.5 part/trillion) in Adige River water, Northern Italy .
RAIN/SNOW: Rainfall in Iowa was sampled from October 1987 through September 1990 from
the Big Spring Basin, Iowa City, and the Bluegrass watershed . Sutan was detected (detection
limit 0.10 ug/l) in 2 of 235 samples at a mean concn of 0.12 ug/l (sites not specified) .
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