| Chemical Abstract Number (CAS #) |
2164172
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| Synonyms | Fluometuron |
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Urea, N,N-dimethyl-N'-[3-(trifluoromethyl)phenyl] |
| Analytical Method |
EPA Method 632 |
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| Molecular Formula | C10H11F3N2O |
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| Use | MOST ANNUAL GRASS & BROADLEAF WEEDS ARE CONTROLLED WITH NO
GEOGRAPHICAL LIMITATIONS. REGISTERED FOR USE ON COTTON &
SUGARCANE BY EPA. IT CONTROLS MONOCOTYLEDONOUS &
DICOTYLEDONOUS WEEDS & CAN BE APPLIED BEFORE PLANTING, AFTER
PLANTING, OR AFTER EMERGENCE OF CROP & WEEDS. CROP PLANTS THAT MAY
BE SENSITIVE: SUGAR BEETS, RED BEETS, COLE CROPS, CUCURBITS, &
EGGPLANTS.
FLUOMETURON IS ESPECIALLY SUITABLE FOR CONTROL OF ANNUAL
BROAD-LEAVED AND GRASS WEEDS OF COTTON AT 1.6-2.7 KG ACTIVE
INGREDIENT/HECTARE; ALSO AS PRE- AND POST-EMERGENCE SPRAYS ON SUGAR
CANE, PINEAPPLE AND COFFEE AT RATES OF 3-4 LB ACTIVE INGREDIENT/ACRE.
HERBICIDAL PROPERTIES ARE SHARED BY THE 4-TRIFLUOROMETHYL
DERIVATIVE BUT NOT BY
N'3,5-BIS(TRIFLUOROMETHYL)PHENYL-N,N-DIMETHYLUREA.
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| Consumption Patterns | 100% AS AN HERBICIDE ON COTTON (1975)
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| Apparent Color | WHITE CRYSTALS; Colorless crystals
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| Odor | ODORLESS
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| Melting Point | 163-164.5 DEG C
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| Molecular Weight | 232.21
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| Density | 1.39 g/cu cm (20 deg C)
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| Sensitivity Data | DUST MAY BE IRRITATING TO THE EYE .
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| Environmental Impact | Fluometuron is a herbicide used primarily for the control of broadleaf weed and grass in
cotton fields. The release of fluometuron in the environment occurs during its manufacture and
particularly from its use in the field. In soil, fluometuron is transformed in the environment
primarily by biodegradation. The half-life of fluometuron disappearance from soil is about 85
days. Fluometuron is highly to moderately mobile in soil. Both biodegradation and photolysis are
expected to be the major pathways for the loss of fluometuron in water. The bioconcentration of
fluometuron in aquatic organisms should not be important. Reaction of vapor phase fluometuron
with photochemically produced hydroxyl radicals may be an important fate process in the
atmosphere (estimated half-life 4.1 hrs). Removal of fluometuron can also occur as a result of dry
and wet deposition. Fluometuron has rarely been detected in surface water, groundwater or food
in the US. The applicators of the herbicide and farm workers are the most likely people for
exposure to fluometuron by inhalation and dermal routes.
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| Environmental Fate | TERRESTRIAL FATE: IT IS OF INTERMEDIATE PERSISTENCE WITH A
HALF-LIFE OF 60-75 DAYS ACCORDING TO SOIL CONDITIONS.
TERRESTRIAL FATE: AVG LOSS OF FLUOMETURON ATTRIBUTED TO RUNOFF
WAS LESS THAN 1% OF THE TOTAL APPLIED. FLUOMETURON IS LEACHED TO A
MODERATE EXTENT IN SOIL. IT HAS A LEACHING INDEX OF 12 WHERE 1 IS VERY
SLIGHT & 20 IS VERY GREAT. THIS MODERATE LEACHING FACTOR IS IMPORTANT
FOR CONTROL OF DEEP GERMINATING WEEDS.
Terrestrial Fate: Fluometuron decreased from 6 ppm to < 0.5 ppm in approximately 165 days in
the 0 to 5 cm layer of a plant-free Swiss clay loam under field conditions. Soil compostion: 18%
clay, 12% silt, 67% sand, < 1% humus; pH 5.7. Herbicide applied at the rate of 4 kg active
ingredient/ha. From figure
TERRESTRIAL FATE: Biodegradation will be the major process by which fluometuron will be
lost from most soils . Some loss of fluometuron from soil surface will occur as a result of
photolysis by sunlight . Based on hydrolysis in water, hydrolysis of fluometuron in soil may not
be important(3,SRC). Both soil thin layer chromatographic and soil leaching studies indicate that
the leaching of fluometuron in soil is very high to medium(2,7). Volatilization is not expected to
contribute significantly to dissipation of fluometuron in the field . Depending on the nature of
soil and climatic conditions, the field half-life of fluometuron in soil ranged from 10-171
days(1,3-6) with an average half-life of 85 days .
AQUATIC FATE: Based on the observed biodegradation in soil , biodegradation of
fluometuron may be important in water. The fast photolysis of fluometuron in water by
natural sunlight indicates that photolysis may be an important process in surface of natural
water. The importance of photolysis will decrease due to light attenuation in turbid water and
with increase in water depth. The hydrolysis of fluometuron in water will not be
important . Based on an estimated value of 1.45X10-9 atm-cu m/mole for the Henry's Law
constant, the rate of volatilization of fluometuron from water will be negligibly small(4,SRC). The
estimated BCF values in the range of 28-45 indicates that bioconcentration of fluometuron
in aquatic organisms will not be important.
ATMOSPHERIC FATE: A vapor pressure of 5.0X10-7 mm Hg at 20 deg C indicates that
fluometuron may be present partially in the vapor phase and partially in the particulate form in
air(2,SRC). Based on an estimation method , gas-phase fluometuron will be removed from the
atmosphere with an estimated half-life of 4.1 hrs due to reaction with photochemically produced
hydroxyl radicals. Since fluometuron in water photolyzed with a half-life of 1.2 days with
natural sunlight , direct photolysis of fluometuron in air may also be important. Partial removal
of particulate fluometuron from the air may occur by dry deposition. The water solubility of
105 mg/l at 20 deg C indicates that both vapor and particle phase fluometuron may be partly
removed from the atmosphere by wet deposition as well.
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| Drinking Water Impact | According to the record maintained in the STORET database of EPA, fluometuron was
not detected in 14 surface water samples from 14 locations nor in any of the 156 groundwater
samples analyzed from 125 locations in the U.S. . At a detection limit of 0.5 ug/l, no
fluometuron was detected in water from 119 wells, springs and municipal drinking water supplies
throughout Arkansas during 1985-1987 .
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