Chlorthal-dimethyl

Pesticide -> EPA IRIS

Herbicides

Active substance -> EU Pesticides database: Not approved

Pesticides -> Herbicides, Other

Pesticide

log Kow = 4.40 @ 25 °C

4.28

CRYSTALS FROM METHANOL

COLORLESS CRYSTALS

LESS THAN 5% IN WATER; GREATER THAN 5% IN CYCLOHEXANONE, ACETONE, XYLENE

Solubility (g/kg solvent @ 25 °C): 120 g in dioxan, 250 g in benzene, 170 g in toluene, 140 g in xylene, 100 g in acetone, 70 g in carbon tetrachloride.

7% @ 25 °C IN CARBON TETRACHLORIDE

water solubility = 0.5 mg/l @ 25 °C

0.0000025 [mmHg]

2.5X10-6 mm Hg at 25 °C

STABLE IN THE PURE STATE

STABLE TO UV IRRADIATION

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

This chemical does not meet GHS hazard criteria for 80% (4 of 5) of all reports.

H411 (20%): Toxic to aquatic life with long lasting effects [Hazardous to the aquatic environment, long-term hazard]

P273, P391, and P501 (click each P-code to see the statement)

Aggregated GHS information provided per 5 reports by companies from 2 notifications to the ECHA C&L Inventory.

Hazard Traits - Environmental tox

Commission Regulation (EC) No 1490/2002

2009/715/EC

Chlorthal-dimethyl: Does not have an individual approval but may be used as a component in a product covered by a group standard. It is not approved for use as a chemical in its own right.

Tolerances for combined residues of the herbicide dimethyl tetrachloroterephthalate and its metabolites monoethyl tetrachloroterephthalate and tetrachloroterephthalic acid (calculated as dimethyl tetrachloroterephthalate) are established in or on the following raw agricultural commodities: Beans (field, dry; mung, dry; snap, succulent); broccoli; brussels sprouts; cabbage; cantaloups; cauliflower; collards; corn; cottonseed; cress (upland); cucumbers; eggplant; garlic; honeydew melons; horseradish; kale; lettuce; mustard (greens); onions; peas (southern, black-eyed); peppers; pimentos; potatoes; rutabagas; soybeans; squash (summer and winter); strawberries; sweet potatoes; tomatoes; turnips; turnips (greens); vegetables (leafy, Brassica (cole)); watermelons; and yams.

Tolerances with regional registration, as defined in 180.1(n), are established for the combined residues of dimethyl tetrachloroterephthalate and its metabolites, calculated as dimethyl tetrachloroterephthalate, in or on the following raw agricultural commodities: radish (roots); and radish (tops).

(AZ) ARIZONA 3500 ug/l

(CA) CALIFORNIA 3,500 ug/l

(WA) WASHINGTON 530 ug/L

(WI) WISCONSIN 70 ug/L

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.

Tolerances for combined residues of the herbicide dimethyl tetrachloroterephthalate and its metabolites monoethyl tetrachloroterephthalate and tetrachloroterephthalic acid (calculated as dimethyl tetrachloroterephthalate) are established in or on the following raw agricultural commodities: Beans (field, dry; mung, dry; snap, succulent), 2 ppm; broccoli, 1 ppm; brussels sprouts, 1 ppm; cabbage, 1 ppm; cantaloups, 1 ppm; cauliflower, 1 ppm; collards, 2 ppm; corn (field, fodder and forage), 0.4 ppm; corn (grain (including field and pop)), 0.05 ppm; corn (pop, fodder and forage), 0.4 ppm; corn (sweet (K + CWHR)), 0.05 ppm; corn (sweet, fodder and forage), 0.4 ppm; cottonseed, 0.2 ppm; cress (upland), 5 ppm; cucumbers, 1 ppm; eggplant, 1 ppm; garlic, 1 ppm; honeydew melons, 1 ppm; horseradish, 2 ppm; kale, 2 ppm; lettuce, 2 ppm; mustard (greens), 5 ppm; onions, 1 ppm; peas (southern, black-eyed), 2 ppm; peppers, 2 ppm; pimentos, 2 ppm; potatoes, 2 ppm; rutabagas, 2 ppm; soybeans, 2 ppm; squash (summer and winter), 1 ppm; strawberries, 2 ppm; sweet potatoes, 2 ppm; tomatoes, 1 ppm; turnips, 2 ppm; turnips (greens), 5 ppm; vegetables (leafy, Brassica (cole)), 5 ppm; watermelons, 1 ppm; and yams, 2 ppm.

Tolerances with regional registration, as defined in 180.1(n), are established for the combined residues of dimethyl tetrachloroterephthalate and its metabolites, calculated as dimethyl tetrachloroterephthalate, in or on the following raw agricultural commodities: radish (roots), 2 ppm; and radish (tops), 15 ppm.

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).

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).

24 locations in the United States were used for the collection of food from April 1982 to April 1984 in the Market Basket Study. Intake of dimethyl tetrachloroterephthalate was 1.9, 2.4, 0.9, 1.2, 1.2, 1.1, 1.8, and 1.8 ng/kg body weight/day, respectively for age groups 6-11 months, 2 yr, 14-16 yr female, 14-16 yr male, 25-30 yr female, 25-30 yr male, 60-65 yr female, 60-65 yr male(1). 27 locations were used for the collection of food from October 1980 to March 1982 in the Market Basket Study. The average daily intake of dimethyl tetrachloroterephthalate in adult foods was 0.137 ug/day in leafy vegetables, 0.0213 ug/day in root vegetables, and 0.007 ug/day in garden fruits (total average daily intake=0.165 ug/day)(2). The average daily intake of dimethyl tetrachloroterephthalate from October 1979 to July 1980 in adult foods was 0.0920 ug/day in leafy vegetables, 0.005 ug/day in root vegetables, and 0.0476 ug/day in garden fruits (total average daily intake=0.145 ug/day)(3). The average daily intake of dimethyl tetrachloroterephthalate in 1976 and 1977, in adult foods, was 0.0011 ug/kg body wt/day(4). In the Market Basket Study (13 locations) for infant and toddler diets, the average daily intake of dimethyl tetrachloroterephthalate for an infant was 0.020 ug/kg of body weight/day in 1978, 0.002 ug/kg of body weight/day in 1979, and not detected in 1980 and 1981/1982; for a toddler, the average daily intake was <0.001 ug/kg of body weight/day for 1978, 1979, 1980, and not detected for 1981/1982(5).

Dimethyl tetrachloroterephthalate was not detected in raccoons in Kansas (detection limit=0.050 mg/kg)(1). Dimethyl tetrachloroterephthalate was not detected in Forster's tern eggs (detection limit = <0.01 ug/g) during a National Contaminant Biomonitoring Program study in Green Bay and Lake Poygan, WI(2).

Dacthal

Endocrine

1 x 10 ^-2 mg/kg-day

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).

Dimethyl tetrachloroterephthalate (CAS # 1861-32-1) was evaluated for subchronic dietary toxicity. The test substance was administered at a 1% dietary level to 5 Sprague-Dawley male albino rats for 28-days. Signs of toxicity included mild to moderate tremors, wheezing, and nasal discharge. Beginning with the 2nd week, small skin lesions were noted on the face and head. Lesion severity increased and some gradually developed into deep sores. All animals survived the 28-day period. There was insufficient data to compare body weight gains and food consumption. Pathological changes included dark and congested livers, congested and pale kidneys and spleens; and kidney and liver weights were higher.

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).

HUMAN VOLUNTEERS HAVE INGESTED 50 MG WITHOUT DETECTABLE EFFECTS.

...DACTHAL.../HAS/ NO PROMINENT CLINICAL TOXICOLOGICAL PROPERTIES.

Tolerances for combined residues of the herbicide dimethyl tetrachloroterephthalate and its metabolites monoethyl tetrachloroterephthalate and tetrachloroterephthalic acid (calculated as dimethyl tetrachloroterephthalate) are established in or on the following raw agricultural commodities: Beans (field, dry; mung, dry; snap, succulent); broccoli; brussels sprouts; cabbage; cantaloups; cauliflower; collards; corn; cottonseed; cress (upland); cucumbers; eggplant; garlic; honeydew melons; horseradish; kale; lettuce; mustard (greens); onions; peas (southern, black-eyed); peppers; pimentos; potatoes; rutabagas; soybeans; squash (summer and winter); strawberries; sweet potatoes; tomatoes; turnips; turnips (greens); vegetables (leafy, Brassica (cole)); watermelons; and yams.

Tolerances with regional registration, as defined in 180.1(n), are established for the combined residues of dimethyl tetrachloroterephthalate and its metabolites, calculated as dimethyl tetrachloroterephthalate, in or on the following raw agricultural commodities: radish (roots); and radish (tops).

(AZ) ARIZONA 3500 ug/l

(CA) CALIFORNIA 3,500 ug/l

(WA) WASHINGTON 530 ug/L

(WI) WISCONSIN 70 ug/L

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.

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.

Used as selective pre-emergence herbicide for control of annual grasses broad-leaved weeds in turf, ornamentals, strawberries, cotton, soybeans, and field beans; [HSDB]

Farming (Pesticides) [Category: Industry]

/IT IS/ PRESENTLY APPROVED FOR USE ON TURF, ORNAMENTALS, STRAWBERRIES, AND AGRONOMIC CROPS INCLUDING COTTON, SOYBEANS, AND FIELD BEANS. /IT IS/ EFFECTIVE AGAINST SMOOTH & HAIRY CRABGRASS, WITCHGRASS, GREEN & YELLOW FOXTAILS, FALL PANICUM & OTHER ANNUAL GRASSES. /IT IS/ ALSO USEFUL AGAINST CERTAIN BROAD-LEAVED WEEDS SUCH AS CARPET WEED...PURSLANE & COMMON CHICKWEED. /IT IS/ TOLERATED BY MANY CROP PLANTS.

IT IS EXTRAORDINARILY TOXIC TO DODDER AND HAS, THEREFORE, BEEN USED FOR DODDER CONTROL IN SEED ALFALFA.

Selective non-systemic herbicide used for pre-emergence control of annual grasses and some annual broad-leaved weeds.

BY ESTERIFICATION WITH METHYL ALCOHOL OF TETRACHLOROTEREPHTHALIC ACID.

THE ESTER IS PRODUCED BY THE CHLORINATION OF TEREPHTHALOYL CHLORIDE...& REACTION WITH METHANOL.

Dimethyl tetrachloroterephthalate can be prepared by chlorination of p-xylene, conversion of the resulting reaction products to 2,3,5,6-tetrachloroterephthaloyl chloride, and reaction with methanol to yield the dimethyl ester.

'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)