Dacthal

331.96

331.96

1888840

217-464-7

ZU3X5G2QLR

155745

DTXSID0024000

CRYSTALS FROM METHANOL|COLORLESS CRYSTALS

29173990

52.6

4.40 @ 25 deg C

Colorless, crystalline solid.

1.6496 (rough estimate)

155-156 °C

365 °C

174.7±26.3 °C

1.5282 (estimate)

H2O: 0.05 g/100 mL

Keep closed in a cool, dry place. Store only with compatible chemicals.

2.5X10-6 mm Hg at 25 deg C

LD50 orally in rats: >3000 mg/kg (Bailey, White)

ESSENTIALLY ODORLESS

DECOMPOSES @ 360-370 °C|SPECIFIC GRAVITY, C: 1.70 /DATHAL W-75/|VAPOR PRESSURES WERE IN RANGE OF 0.0007-1.478 TORR @ 75-160 °C|Stable to heat and UV light

AVG MOLAR VAPORIZATION HEAT IS CALCULATED TO BE 25 KCAL/MOL

UN3077 Environmentally hazardous substances, solid, n.o.s., Hazard class: 9; Labels: 9-Miscellaneous hazardous material, Technical Name Required.

2

22-24/25

WZ1500000

STABLE TO UV IRRADIATION

SRP: At the time of review, criteria for land treatment or burial (sanitary landfill) disposal practices are subject to significant revision. Prior to implementing land disposal of waste residue (including waste sludge), consult with environmental regulatory agencies for guidance on acceptable disposal practices.|Incineration could be used for disposal with proper precautions for the hydrogen chloride formed, that is, caustic scrubbers would be required for any large amt. Recommendable method: Incineration.

12% of the sediment samples taken from the Moss Landing drainage area in California during 1986 contained dimethyl tetrachloroterephthalate (concentration = not detected to 25 ug/kg dry weight detection limit = 8.8 ug/kg)(1).

URBAN/SUBURBAN: Indoor and outdoor air samples collected monthly for 1 year at homes of occupationally exposed men in Colorado showed the presence of dimethyl tetrachloroterephthalate at similar concentrations for all conditions (farmers indoor, n=38, 31 positive, range=0.08-12.04 ug/sq m; farmers outdoor, n=37, 31 positive, range=0.02-9.12 ug/sq m; formulators indoor, n=52, 48 positive, range=0.05-8.72 ug/sq m; formulators outdoor, n=54, 39 positive, range=0.08-38.26) indicating that these concentrations of dimethyl tetrachloroterephthalate prevail throughout the study area(1). Indoor, outdoor, and personal air samples were collected in winter, spring and summer in Jacksonville, FL and Springfield/Chicopee, MA to assess non-occupational exposure to dimethyl tetrachloroterephthalate. Jacksonville residents had low exposures (indoor, mean summer=0.2 ng/cu m, not detected in spring, 0.3 ng/cu m in winter; outdoor, not detected in summer, spring, winter; personal, summer=0.6 ng/cu m, not detected in spring, 0.2 ng/cu m in winter) while Springfield/Chicopee residents were exposed to higher levels (indoor, mean spring=1.6 ng/cu m, 0.3 ng/cu m in winter; outdoor, mean spring=0.9 ng/cu m, not detected in winter; personal, spring=2.6 ng/cu m, 0.3 ng/cu m in winter)(2).|URBAN/SUBURBAN: The arithmetic mean airborne pesticide concentration of dimethyl tetrachloroterephthalate in the US in 1970-71 equalled trace levels of this compound (0.49% positive samples, maximum value=2.1 ng/cu m)(1,2).

39% of the soil samples taken from the Moss Landing drainage area(concentration=not detected to 690 ug/kg dry weight) and 47% taken from the Salinas and Carmel River Valley agricultural areas (concentration=not detected to 700 ug/kg dry weight) in California, during 1986, contained dimethyl tetrachloroterephthalate(detection limit=4.4 ug/kg)(1). 1533 sites in 37 states in 1972 were tested for the presence of dimethyl tetrachloroterephthalate in soil (detected in 1 sample or 0.1% of the total samples, concentration=0.18 ppm)(2). Household dust samples from Colorado showed the presence of dimethyl tetrachloroterephthalate (control group, n=182, positive=14, mean concentration=7.11 ppb; farmers, n=45, positive=22, mean=18.50 ppb; formulators, n=95, positive=19, mean=7.28 ppb)(3). Dimethyl tetrachloroterephthalate was detected in carpet dust in 2 of 9 houses in Raleigh-Durham-Chapel Hill area, NC(4).

LD50 Rat oral > 10000 mg/kg|LD50 Rat albino dermal > 10000 mg/kg|LC50 Rat inhalation > 5 mg/l (4 hr nominal)

Dimethyl tetrachloroterephthalate is released directly to the environment during its use as a pre-emergence herbicide(SRC) for the control of annual grasses and some annual broad-leaved weeds(1).

TERRESTRIAL FATE: An estimated Koc of 5900(1,SRC), based on an experimental log Kow of 4.40(2), indicates that dimethyl tetrachloroterephthalate will be essentially immobile in soil(3). Dimethyl tetrachloroterephthalate moves minimally in the soil profile due to its adsorption to clay and organic matter(4). Some loss of dimethyl tetrachloroterephthalate due to volatilization from moist soil surfaces may be possible based on an estimated Henry's Law constant of 2.18X10-6 atm-cu m/mol. In a field experiment, the loss of dimethyl tetrachloroterephthalate followed an apparent first-order dissipation rate for 85 days following application with a calculated soil half-life of 33.8 days. The total estimated loss by volatilization from the soil surface for the 21 day sampling period was 0.74 or 1.06 kg/ha(5). Approximately 36-52% of the total measured dimethyl tetrachloroterephthalate loss from soil was accounted for by volatilization and 26% by breakdown in soil during this 21 day period(5). A majority of the loss by flux occurred following irrigation; when the soil surface was dry, loss was minimal(5). Dimethyl tetrachloroterephthalate was sprayed as a 75% wettable powder onto a moist Hatboro silt loam (23% sand, 57% silt, 20% clay, 1.2% organic matter(6). A 2% volatilization loss of this pesticide required 34 hours(6); a 50% volatilization loss of dimethyl tetrachloroterephthalate required 8 days following surface application in the same study(7). Dimethyl tetrachloroterephthalate-treated soil (fine, sandy loam) under conditions of both unrestricted and restricted volatilization and microbial degradation (at 60 and 90 °F) showed results indicating that this compound is not subject to large losses due to volatilization or microbial action over a period of 70 days(8).|TERRESTRIAL FATE: Biodegradation is expected to be a major fate process for this compound with the degradation of dimethyl tetrachloroterephthalate occurring by successive dealkylations of the two methyl groups at the ester linkages with the formation of monomethyl tetrachloroterephthalate and tetrachloroterephthalic acid(2). Two studies measured the optimal temperature and moisture conditions for the biodegradation of dimethyl tetrachloroterephthalate(2,3); at 20-30 °C and with 0.2 kg H2O/kg soil present a half-life of 11 days was obtained. At 10-15 °C and only 0.1 kg H2O/kg soil dimethyl tetrachloroterephthalate had a half-life of 105 days(2). However, land which had been sprayed with dimethyl tetrachloroterephthalate for five years and then not sprayed for the following three years still had measurable residues of this compound present(4). On soil surfaces, dimethyl tetrachloroterephthalate may photodegrade. Following 5 hours of exposure to sunlight, 50% of this compound was degraded to monomethyl tetrachloroterephthalic acid, tetrachloroterephthalic acid and 1,2,4,5-tetrachlorobenzene(5).|AQUATIC FATE: Given an estimated Koc of 5900(1,SRC), determined from an experimental log Kow of 4.40(2), dimethyl tetrachloroterephthalate should bind strongly to particulate matter and sediment in the water column(3); this will be a major fate process for this compound(SRC). Biodegradation of dimethyl tetrachloroterephthalate is also expected to be a major fate process based on aerobic soil biodegradation studies. Half-lives for this compound in soil (dependent on temperature and moisture conditions) ranged from 11 to 289 days(4-8); the degradation of dimethyl tetrachloroterephthalate occurs by successive dealkylations of the two methyl groups at the ester linkages with the formation of monomethyl tetrachloroterephthalate and tetrachloroterephthalic acid(4). Dimethyl tetrachloroterephthalate is expected to bioconcentrate in aquatic organisms based on an estimated BCF value of 1300(2,9,SRC); this compound has been detected in fish at several locations in the US(9-18).|ATMOSPHERIC FATE: Based on an experimental vapor pressure of 2.5X10-6 mm Hg at 25 °C(1,SRC), dimethyl tetrachloroterephthalate will exist in both the vapor phase and the particulate phase in the ambient atmosphere(2). Dimethyl tetrachloroterephthalate is expected to degrade in the vapor phase by reaction with photochemically produced hydroxyl radicals with an estimated half-life of 36 days(3,SRC). Particulate-phase dimethyl tetrachloroterephthalate may be removed physically from air by wet and dry deposition(SRC).

AFTER APPLICATION OF DACTHAL TO SOIL, MONOMETHYL AND FREE DICARBOXYL ANALOGS WERE TENTATIVELY IDENTIFIED BY GAS CHROMATOGRAPHY. UNDER CONDITIONS OF GAS CHROMATOGRAPHY, MONOMETHYL DERIV UNDERWENT DECARBOXYLATION.|This compound is reported to be stable to both heat and UV light(1). however, a thin layer of dimethyl tetrachloroterephthalate placed on a glass plate and then exposed to sunlight from 2 to 96 hours showed 50% decomposition of this herbicide after exposure for 5 hours, and above 95% decomposition after 48 hours(2). Dimethyl tetrachloroterephthalate was photodecomposed to monomethyl tetrachloroterephthalic acid and tetrachloroterephthalic acid following exposure for two hours, and 1,2,4,5-tetrachlorobenzene as well was formed following four hours. After 64 hours, more unidentified products were noted(2). In methanol, dimethyl tetrachloroterephthalate does not absorb above 330 nm(3). The rate constant for the vapor-phase reaction of dimethyl tetrachloroterephthalate with photochemically produced hydroxyl radicals has been estimated as 4.41X10-13 cu cm/molecule-sec at 25 °C(4,SRC). The half-life of dimethyl tetrachloroterephthalate is estimated to be 36 days based on a hydroxyl radical concentration of 5X10+5(4,SRC).

A BCF of 1300 was calculated for dimethyl tetrachloroterephthalate, using an experimental log Kow of 4.40(1) and a recommended regression-derived equation(2,SRC). This BCF value suggests that dimethyl tetrachloroterephthalate will bioconcentrate in aquatic organisms(2). Multiple studies show the presence of dimethyl tetrachloroterephthalate in fish(3-12) indicating that bioconcentration of this compound does occur.

5.01e+03 L/kg|Based on an experimental log Kow of 4.40(1), the Koc of dimethyl tetrachloroterephthalate is estimated as approximately 5900 using a regression-derived equation(2,SRC). According to a suggested classification scheme, this Koc value suggests that dimethyl tetrachloroterephthalate is essentially immobile in soil(3). Dimethyl tetrachloroterephthalate is reported to absorb strongly to soil and to be resistant to leaching(4). The minimal movement of dimethyl tetrachloroterephthalate in soil suggests that this compound may adsorb to organic matter or clay(5).

The Henry's Law constant for dimethyl tetrachloroterephthalate was determined from experimental values of vapor pressure(1) and water solubility(2) as 2.18X10-6 atm-cu/mole(3,SRC). This indicates that volatilization of dimethyl tetrachloroterephthalate from water surfaces is slow(3).

SURFACE WATER: Dimethyl tetrachloroterephthalate was detected in unfiltered river water samples between 1972-1973 on the lower Rio Grande (concentrations=not detected to 132 ppb)(1).|GROUNDWATER: In a national summary of groundwater wells, 5 wells of 2033 total, tested from 1984-1991, had measurable concentrations of dimethyl tetrachloroterephthalate (from 0.010-300 ug/l)(1). In a national pesticide survey of drinking water wells(783 rural domestic, 566 community wells), dimethyl tetrachloroterephthalate was not detected(minimum reporting limit 0.060 ug/l)(2). Dimethyl tetrachloroterephthalate was detected in New York State groundwater (median concentration of 109 ppb, maximum concentration of 1039 ppb)(3). In a 1979-1980 Long Island, New York study, dimethyl tetrachloroterephthalate residues were detected in 6 of 10 wells in an agricultural area (concentrations 40-600 ppb, sampling done monthly over one year)(4). A dimethyl tetrachloroterephthalate metabolite was detected in 3 of 1791 wells in Wisconsin(5). Dimethyl tetrachloroterephthalate was detected in 4 California wells at unreported concentrations(6).

Produce samples from 1989-1990 were tested for the presence of dimethyl tetrachloroterephthalate(n=6970, approximately 80% domestic, 20% foreign, detection limit=0.125 ppm, 50 samples with residues reported). Dimethyl tetrachloroterephthalate was detected in broccoli samples(n=203, 2.5% incidence), greens (n=153, 1.3%), lettuce (1.3%), onions (1.2%), and turnips (n=44, 9.0%)(1). In the 1982-1984 Market Basket Study, dimethyl tetrachloroterephthalate residues were found in 2% of the total samples(n=over 5000)(2). In the 1980-1982 Market Basket Study (27 locations) for adult diets, dimethyl tetrachloroterephthalate was detected in leafy vegetables (9 positive, concentration=trace- 0.057 ppm), root vegetables (12 positive, concentration=trace- 0.004 ppm), and garden fruits (2 positive, concentration=trace- 0.002 ppm)(3). Market Basket studies for years 1974 to 1980, for adult diets, detected dimethyl tetrachloroterephthalate in leafy vegetables (11 positive, concentration=trace-0.017 ppm), root vegetables (7 positive, concentration=trace-0.002 ppm), garden fruits (9 positive, concentration=trace-0.008 ppm), and oils/fats (2 positive, concentration=0.002-0.004 ppm)(4-8).|Market Basket studies for years 1968 to 1974, for adult diets, detected dimethyl tetrachloroterephthalate 10 times with a concentration range from trace levels to 0.032 ppm(1-4). Dimethyl tetrachloroterephthalate was detected in raw agricultural products, domestically produced (leaf and stem vegetables with 0.5% incidence and an average concentration of <0.005 ppm)(5). Total diet samples from 1964- 1968 showed a 3% incidence of dimethyl tetrachloroterephthalate residues with an average concentration of <0.001 ppm(5).

Nonoccupational exposure will result from the inhalation of both indoor and outdoor air, particularly near agricultural areas(1-4), and carpet dust(5,6). Dimethyl tetrachloroterephthalate is a contaminant in some drinking water wells(7-11). Ingestion of leafy and root vegetables will result in the uptake of small quantities of dimethyl tetrachloroterephthalate(12,13).|Dimethyl tetrachloroterephthalate was detected in the hand rinsings from 2 of 11 people who were occupationally exposed to the herbicide (positives=2, from 1-112 days following exposure)(1).

IT IS METABOLIZED IN ANIMALS TO MONOMETHYL ESTER AND CHLORTHAL WHICH ARE ELIMINATED IN URINE.|METABOLISM STUDIES IN MAN & DOG INDICATE THAT...HYDROLYSIS OF ESTER BONDS OCCUR...RESULTING IN URINARY EXCRETION OF MONO- OR DICARBOXYLIC ACID DERIV. REMAINDER /IS/ EXCRETED UNCHANGED IN FECES. NO APPRECIABLE STORAGE IN BODY TISSUE HAS BEEN DEMONSTRATED.|NO RESIDUES OF DACTHAL WERE FOUND IN MILK OF DAIRY COWS FED THIS CMPD. ABOUT 1% OF INTACT DACTHAL WAS FOUND IN MANURE. DACTHAL MONOACID, 2,3,5,6-TETRACHLOROMONOMETHYLTEREPHTHALATE, WAS ELIMINATED VIA MANURE (3.3%) AND URINE (90.9%).|...NOT ABSORBED BY FOLIAGE. ...NOT TRANSLOCATED IN THE PLANT. ...KILLS GERMINATING SEEDS; EXACT MECHANISM NOT YET KNOWN. ...NOT CONSIDERED TO BE METABOLIZED BY PLANTS.

DACTHAL MONOACID, 2,3,5,6-TETRACHLOROMONOMETHYLTEREPHTHALATE, WAS ELIMINATED VIA MANURE (3.3%) AND URINE (90.9%). BEEF LIVER SLICES RAPIDLY PRODUCED THIS SAME METABOLITE. INCUBATION OF DACTHAL WITH RUMEN CONTENTS DID NOT DECOMPOSE DACTHAL.|Studies in man and dog indicate that substantial hydrolysis of the ester bonds occurs ... resulting in the urinary excretion of mono- or dicarboxylic acid derivatives.

Dimethyl tetrachloroterephthalate is known to contain hexachlorobenzene at <0.3%.

HUMAN VOLUNTEERS HAVE INGESTED 50 MG WITHOUT DETECTABLE EFFECTS.|...DACTHAL.../HAS/ NO PROMINENT CLINICAL TOXICOLOGICAL PROPERTIES.

Dacthal

'DACTHAL W-75', WP (750 G I/KG); 'DIMETHYL-7',WP (750 G/KG); 'DACTHAL G-5', 30-60 MESH GRANULES (50 G/KG).|FATAL|RID|TCTP|For more Formulations/Preparations (Complete) data for DIMETHYL TETRACHLOROTEREPHTHALATE (14 total), please visit the HSDB record page.

INCOMPATIBILITIES: COMPATIBLE WITH MOST OTHER PESTICIDES; NO UNUSUAL HARD WATER PROBLEMS.|IT IS PRE-EMERGENCE HERBICIDE RECOMMENDED FOR CONTROL OF ANNUAL WEEDS IN MANY CROPS @ RATES OF 6-14 KG/HECTARE.|US Patent 2,923,634 for preparation; Lindeman (1960 to Diamond Alkali)

ANALYSIS.../IS/ BY GAS CHROMATOGRAPHY; BY INFRARED; METHOD AVAILABLE FROM DIAMOND SHAMROCK CHEMICAL COMPANY.|...RESIDUES MAY BE DETERMINED BY COLORIMETRIC METHOD AND COULOMETRIC GAS LIQ CHROMATOGRAPHY.|GENERAL SAMPLE, GAS CHROMATOGRAPHY. GENERAL SAMPLE; COLUMN CHROMATOGRAPHY; GAS CHROMATOGRAPHY. DETERMINATION OF RESIDUES OF DACTHAL HERBICIDE IN VEGETABLES & AGRONOMIC CROPS.|GENERAL SAMPLE; COLUMN CHROMATOGRAPHY; GAS CHROMATOGRAPHY. DETERMINATION OF RESIDUES OF DACTHAL HERBICIDE IN VEGETABLES & AGRONOMIC CROPS.|For more Analytic Laboratory Methods (Complete) data for DIMETHYL TETRACHLOROTEREPHTHALATE (10 total), please visit the HSDB record page.

Agrochemicals -> Herbicides|HERBICIDES