| Chemical Abstract Number (CAS #) |
5915413
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| Synonyms | Terbuthylazine |
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1,3,5-Triazine-2,4-diamine, 6-chloro-N-(1,1-dimethylethyl)-N'-ethyl- | 2-tert-Butylamino-4-chloro-6-ethylamino-s-triazine | Gardoprim | Primatol M |
| Analytical Method |
EPA Method 619 |
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| Molecular Formula | C9H16ClN5 |
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| Use | AS A HERBICIDE TO CONTROL WIDE RANGE OF WEEDS & AS
PRE-EMERGENCE HERBICIDE IN SORGHUM (1.2-1.8 KG AI/HA); ALSO FOR
SELECTIVE WEED CONTROL IN CITRUS, MAIZE, POD FORESTS & VINEYARDS
/FORMER USE
MIXED WITH TERBUMETON IT CONTROLS PERENNIAL WEEDS IN ESTABLISHED
STANDS OF APPLES, CITRUS AND GRAPES. IT IS USED FOR NON SELECTIVE WEED
CONTROL WHEN MIXED WITH SECBUMETON & IT IS ALSO USED IN
COMBINATION WITH BROMOFENOXIM @ TOTAL AI RATES OF 0.8-1.25 KG/HA AS A
BROAD SPECTRUM BROAD LEAVED HERBICIDE IN WINTER & SPRING CEREALS.
/FORMER USE
IN AFFORESTATION AREAS AND NONCROP SITUATIONS.
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| Apparent Color | COLORLESS POWDER; WHITE SOLID
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| Melting Point | 177-179 DEG C
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| Molecular Weight | 229.7
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| Density | 1.188 G/CU CM @ 20 DEG C
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| Environmental Impact | Terbutylethylazine is not used in the US, but is used in Europe on various crops. If
terbutylethylazine is released to soil, it will be expected to exhibit mobility in soil which can vary
from high to low and therefore it may leach to groundwater. Terbutylethylazine may be subject to
slow degradation in soil which may be due to both slow chemical hydrolysis and slow
biodegradation based upon limited data for terbutylethylazine and other structurally related
s-triazines. The half-lives for degradation of terbutylethylazine in Hatzenbuhl soil at pH 4.8 and
Neuhofen soil at pH 6.5 are 84 and 170 days, respectively. The hydrolysis product is
2-hydroxy-4-tert-butylamino-6-ethylamino-1,3,5-triazine. The total concn of terbutylethylazine in
treated forest soils decreased by a factor of approximately 2 over the course of one growing
season. In greenhouse experiments with a sandy loam soil, the herbicidal activity decreased to a
50% level in 4.5 to 60 weeks at an application rate of 0.33 pounds/acre and >60 weeks at rates of
1.0 and 3.0 pound/acre; activity decreased to a 20% level in >60 weeks at all three application
rates tested. It will not be expected to volatilize from near surface soils or surfaces. If released to
water, terbutylethylazine will not be expected to bioconcentrate in aquatic organisms or to
volatilize. It may adsorb to sediment and suspended particulate matter. The hydrolysis half-lives
for terbutylethylazine is aqueous buffer solutions at 25 deg C at pH 5, 7, and 9 are 63, >200, and
days, respectively. The rate of hydrolysis may be increased by various catalysts such as suspended
soil. No data were located on the biodegradation of photolysis of terbutylethylazine in natural
waters. If terbutylethylazine is released to the atmosphere, it will probably exist both in the
vapor-phase and the particulate phase based upon a reported vapor pressure of 1.13X10-6 mm
Hg. It may be subject to gas-phase reaction with photochemically produced hydroxyl radicals with
an estimated half-life for this process of about 3.0 hr.
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| Environmental Fate | TERRESTRIAL FATE: IT REMAINS LARGELY IN THE TOP SOIL.
THE RELATIVE DEGREE OF PROTONATION & HYDROLYSIS OF VARIOUS
S-TRIAZINES, INCLUDING TERBUTYLETHYLAZINE, BY
CALCIUM-MONTMORILLONITE WAS ESTIMATED BY MEASUREMENT OF THE
RELATIVE INTENSITIES OF IR BANDS & AFTER EXPOSURE OF FILMS OF
CALCIUM-CONTMORILLONITE TO CHLOROFORM SOLN OF S-TRIAZINES FOR 2 WK.
USE OF MATCHED FILMS OF CALCIUM-MONTMORILLONITE IN REFERENCE &
SAMPLE BEAMS MADE IT POSSIBLE TO OBTAIN DIFFERENTIAL SPECTRA DUE
ONLY TO ADSORBED S-TRIAZINE, ELIMINATING THE DIFFICULTY OF
INTERFERENCE BY THE DEFORMATION BAND OF ADSORBED WATER ON CLAY.
THE EFFECT OF SUBSTITUTIONS AT THE 2-, 4-, & 6-POSITIONS WAS ALSO
STUDIED. IN GENERAL THE DEGREE OF PROTONATION & HYDROLYSIS DECR AS
THE NUMBER OF CARBON ATOMS AT THE 4-, & 6-POSITIONS INCR. THESE
OBSERVATIONS CAN AID IN PREDICTING THE BEHAVIOR OF S-TRIAZINES IN
SOILS AS WELL AS IN FORMULATION CONTAINING SIMILAR MINERAL SURFACES.
TERRESTRIAL FATE: If terbutylethylazine is released to soil, it will be expected to exhibit
mobility in soil which can vary from high to low and therefore it may leach to groundwater.
Terbutylethylazine may be subject to slow degradation in soil which may be due to both chemical
hydrolysis and biodegradation based upon limited data for terbutylethylazine and other structurally
related s-triazines. The half-lives for degradation (purportedly mainly soil catalyzed hydrolysis) of
terbutylethylazine in Hatzenbuhl soil at pH 4.8 and Neuhofen soil at pH 6.5 are 84 and 170 days,
respectively . The product of hydrolysis is
2-hydroxy-4-tert-butylamino-6-ethylamino-1,3,5-triazine . The rate of hydrolysis may be
increased by various catalysts based upon the observed increase in rate of hydrolysis rates for the
chemically similar herbicide atrazine in water solutions upon addition of sterilized soil and
humic and fulvic acids . The total concn of terbutylethylazine in treated forest soils decreased
by a factor of approximately 2 over the course of one growing season . In greenhouse
experiments with a sandy loam soil, the herbicidal activity decreased to a 50% level in 4.5 to 60
weeks at an application rate of 0.33 pounds acre and >60 weeks at all three application rates
tested(6). It will not be expected to volatilize from near surface soils or surfaces.
AQUATIC FATE: If released to water, terbutylethylazine will not be expected to bioconcentrate
in aquatic organisms or to volatilize. It may adsorb to sediment and suspended particulate matter.
The hydrolysis half-lives for terbutylethylazine in aqueous buffer solutions at 25 deg C at pH 5, 7,
and 9 are 63, >200, and >200 days, respectively . The rate of hydrolysis may be increased by
various catalysts such as suspended soil . No data were located on the biodegradation of
photolysis of terbutylethylazine in natural waters.
ATMOSPHERIC FATE: If terbutylethylazine is released to the atmosphere, it will probably
exist both in the vapor phase and the particulate phase based upon a reported vapor pressure of
1.13X10-6 mm Hg . It may be subject to gas phase reaction with hydroxyl radicals and
photolysis. The rate constant for the vapor phase reaction of terbutylethylazine with
photochemically produced hydroxyl radicals has been estimated to be 129.2 cu cm/molecule-sec
at 25 deg C which corresponds to an atmospheric half-life of about 3.0 hr at an atmospheric
concn of 5X10 5 hydroxyl radicals per cu cm .
TERRESTRIAL FATE: THE LONG SOIL PERSISTENCE OF THESE CMPD DOES
CREATE THE PROBLEM OF SOIL CARRY OVER, WHICH CAN DAMAGE
SUCCEEDING CASH CROPS. THEREFORE EXTREME CAUTION MUST BE TAKEN IN
THEIR APPLICATION ON CROPLAND TO AVOID SUCH INJURY TO FOLLOWING
CROPS. TRIAZINES
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| Drinking Water Impact | SURFACE WATER: Terbutylethylazine was detected in the following numbers of
samples out of 708 total samples from Central European streams in spring 1976 to fall 1977
within the indicated concn ranges: 4 samples 1.1-10 ppb; 11 samples 0.4-1.0 ppb; 103 samples
<0.4 ppb . Terbutylethylazine was found in Swedish stream waters (1985-1987) in 2 of 114
samples taken during June-July at a max concn of 0.7 ppb and not detected in 203 samples taken
during April-May and Aug-Oct .
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