Acetochlor

269.76700

269.77

251-899-3

8L08WMO94K

DTXSID8023848

Clear, viscous liquid|Pale straw-colored oil|Thick, oily liquid, light amber to violet

3808931100

29.54000

3.12320

Oily liquid at room temperature, light amber to violet color. Aromatic odor.

1.1

<0 °C

162 °C

>68ºC

1.5272 (20ºC)

soluble in diethyl ether, benzene, chloroform, ethyl acetate

0-6ºC

2.2X10-2 mPa /1.67X10-7 mm Hg/ at 20 deg C

LD50 orally in rats: 1160 mg/kg (Upchurch)

Aromatic odor

Henry's Law constant = 2.66X10-10 atm-cu m/mol at 25 °C (est)

160.09 Ų [M+H]+ [CCS Type: DT, Method: stepped-field]|174.6 Ų [M+Na]+ [CCS Type: DT, Method: stepped-field]|157.4 Ų [M+H]+ [CCS Type: DT, Method: single field calibrated]|173.5 Ų [M+H]+

Wine red to yellow or amber oil /Technical acetochlor/|Hydroxyl radical reaction rate constant = 4.96X10-11 cu cm/molec-sec at 25 °C (est)

Formulations are sightly corrosive to mild steel

UN3082 9/PG 3

2

R20; R37/38; R43; R50/53

S2-S36/37-S60-S61

AB5457000

Xn

Stable for over 2 years at 20 deg C (EC formulation)

P261-P273-P280-P501

H315-H317-H332-H335-H410

SRP: The most favorable course of action is to use an alternative chemical product with less inherent propensity for occupational harm/injury/toxicity or environmental contamination. Recycle any unused portion of the material for its approved use or return it to the manufacturer or supplier. Ultimate disposal of the chemical must consider: the material's impact on air quality; potential migration in soil or water; effects on animal and plant life; and conformance with environmental and public health regulations.|SRP: Wastewater from contaminant suppression, cleaning of protective clothing/equipment, or contaminated sites should be contained and evaluated for subject chemical or decomposition product concentrations. Concentrations shall be lower than applicable environmental discharge or disposal criteria. Alternatively, pretreatment and/or discharge to a permitted wastewater treatment facility is acceptable only after review by the governing authority and assurance that "pass through" violations will not occur. Due consideration shall be given to remediation worker exposure (inhalation, dermal and ingestion) as well as fate during treatment, transfer and disposal. If it is not practicable to manage the chemical in this fashion, it must be evaluated in accordance with EPA 40 CFR Part 261, specifically Subpart B, in order to determine the appropriate local, state and federal requirements for disposal.|Do not contaminate water, food, or feed by storage or disposal. Open dumping is prohibited. Do not reuse empty container. /Dupont Breakfree Herbicide/|Safe Disposal of Pesticides. The best way to dispose of small amounts of excess pesticides is to use them - apply them - according to the directions on the label. If you cannot use them, ask your neighbors whether they have a similar pest control problem and can use them. If all of the remaining pesticide cannot be properly used, check with your local solid waste management authority, environmental agency, or health department to find out whether your community has a household hazardous waste collection program or a similar program for getting rid of unwanted, leftover pesticides. These authorities can also inform you of any local requirements for pesticide waste disposal. /Residential users/|Safe Disposal of Pesticides. An empty pesticide container can be as hazardous as a full one because of residues left inside. Never reuse such a container. When empty, a pesticide container should be rinsed carefully three times and the rinsewater thoroughly drained back onto the sprayer or the container previously used to mix the pesticide. Use the rinsewater as a pesticide, following label directions. Replace the cap or closure securely. Dispose of the container according to label instructions. Do not puncture or burn a pressurized container like an aerosol - it could explode. Many communities have programs to recycle household waste such as empty bottles and cans. Do not recycle any pesticide containers, however, unless the recycling program specifically accepts pesticide containers and you follow the program's instructions for preparing the empty containers for collection. /Residential users/

USEPA/Office of Pesticide Programs; Report of the Food Quality Protection Act (FQPA) Tolerance Reassessment Progress and Risk Management Decision (TRED) for Acetochlor, EPA 738-R-00-009 (March 2006). EPA issues a TRED for a pesticide that requires tolerance reassessment decisions, but does not require a reregistration eligibility decision at present because: the pesticide was initially registered after November 1, 1984, and by law is not included within the scope of the reregistration program; EPA completed a RED for the pesticide before FQPA was enacted on August 3, 1996; or the pesticide is not registered for use in the U.S. but tolerances are established that allow crops treated with the pesticide to be imported from other countries.[Available from, as of January 26, 2012: http://www.epa.gov/pesticides/reregistration/status.htm]

|Warning|H315: Causes skin irritation [Warning Skin corrosion/irritation]|P201, P202, P260, P261, P264, P271, P272, P273, P280, P281, P302+P352, P304+P312, P304+P340, P308+P313, P312, P314, P321, P332+P313, P333+P313, P362, P363, P391, P403+P233, P405, and P501|H315 (100%): Causes skin irritation [Warning Skin corrosion/irritation]|Aggregated GHS information provided by 286 companies from 10 notifications to the ECHA C&L Inventory. Each notification may be associated with multiple companies.|Danger|H350: May cause cancer [Danger Carcinogenicity]|P201, P202, P260, P264, P270, P273, P281, P308+P313, P314, P391, P405, and P501

Applicators and other handlers must wear: Coveralls over short-sleeved shirt and short pants; Chemical-resistant gloves made of any waterproof material such as polyethylene or polyvinyl chloride; Chemical-resistant footwear plus socks; Protective eyewear; Chemical-resistant headgear for overhead exposure; and Chemical-resistant apron when cleaning equipment, mixing, or loading. /DuPont Breakfree Herbicide/

Wear self-contained breathing apparatus (SCBA) and full protective equipment. /Dupont Breakfree Herbicide/|Extinguishing Media: Water fog, "alcohol" foam, CO2, dry chemical. /Dupont Breakfree Herbicide/

Do not contaminate /receiving/ water when disposing of equipment washwaters or rinsate. /DuPont Breakfree Herbicide/|In case of spill or leak on floor or paved surfaces, soak up with vermiculite, earth, or synthetic absorbent. /DuPont Breakfree Herbicide/|If a spill occurs, clean it up promptly. Don't wash it away. Instead, sprinkle the spill with sawdust, vermiculite, or kitty litter. Sweep it into a plastic garbage bag, and dispose of it as directed on the pesticide product label./Residential users/|After Applying a Pesticide, Indoors or Outdoors. To remove pesticide residues, use a bucket to rinse tools or equipment three times, including any containers or utensils that you used when mixing the pesticide. Then pour the rinsewater into the pesticide sprayer and reuse the solution by applying it according to the pesticide product label directions. After applying any pesticide wash your hands and any other parts of your body that may have come in contact with the pesticide..To prevent tracking pesticides inside, remove or rinse your boots or shoes before entering your home. Wash any clothes that have been exposed to a lot of pesticide separately from your regular wash. /Residential users/

Use this product only in accordance with its labeling and with the Worker Protection Standard, 40 CFR part 170. /DuPont Breakfree Herbicide/|Do not apply directly to water, or to areas where surface water is present or to intertidal areas below the mean high water mark. /DuPont Breakfree Herbicide/|Do not enter or allow worker entry into treated areas during the restricted entry interval (REI) of 12 hours. Exception: If the product is soil-injected or soilincorporated, the Worker Protection Standard, under certain circumstances, allows workers to enter the treated area if there will be no contact with anything that has been treated. /DuPont Breakfree Herbicide/|/Restricted-entry interval (REI) of 4 hours./ PPE required for early entry to treated areas that is permitted under the Worker Protection Standard and that involves contact with anything that has been treated, such as plants, soil, or water, is: Coveralls over short-sleeved shirt and short pants; Chemical-resistant gloves made of any waterproof material; Chemical-resistant footwear plus socks; Protective eyewear; and Chemical-resistant headgear for overhead exposure. /DuPont Breakfree Herbicide/|For more Preventive Measures (Complete) data for ACETOCHLOR (15 total), please visit the HSDB record page.

... Acetochlor ... is irritating ... /to/ the respiratory system and ... skin

The percentage of acetochlor wet deposition as a percentage of its usage in the Choptank River watershed of the Chesapeake Bay on the Delmarva Peninsula (year 2000) was reported at 0.027%(1).

SEDIMENT: A mean acetochlor concentration of 16.3 pg/g (range of 7.20 to 101 pg/g) was reported in sediment samples from Beijing Guanting Reservoir, China, sampled in September, November 2003 and June, August 2004(1).

RURAL/REMOTE: Estimated acetochlor concentrations in the atmosphere of the Mississippi River Valley in April to September 1995 was 12 pg/cu m, present in the gas and particulate phase(1).

LC50 Rat inhalation 3.99 mg/L/4 hr|LD50 Rat oral 1929 mg/kg bw|LD50 Rat oral 2148 mg/kg|LD50 Rat oral 2953 mg/kg /Emulsifiable concentrate (8 lb/gal)/|For more Non-Human Toxicity Values (Complete) data for ACETOCHLOR (7 total), please visit the HSDB record page.

/AQUATIC SPECIES/ After exposure of Bufo raddei tadpoles to acetochlor (ACETO) for 14 days, malondialdehyde (MDA) and DNA-single strand break (DNA-SSB) in livers were analyzed. An enhanced accumulation of MDA suggests that ACETO causes oxidative stress, and the significant increase in the level of DNA-SSB indicates that ACETO induces DNA damage in a dose-dependent manner as well. On the basis of the fact that oxidative stress is caused by excessive production of reactive oxygen species (ROS), and the present results, we speculate that ACETO-induced DNA damage may be a consequence of the generation of ROS. To evaluate this hypothesis, tadpoles were treated with ROS scavenger, N-acetyl-L-cysteine (NAC) or melatonin (MEL), prior to ACETO exposure. The decrease of DNA-SSB level and the increase of total antioxidant capability (TAC) show that ACETO-caused DNA damage can be attenuated by NAC and MEL. In addition, a negative correlation was observed between the extent of DNA damage and the level of TAC in tadpole liver.|/AQUATIC SPECIES/ The effects of a simple mixture of a glyphosate-based formulation and AMPA (Aminomethylphosphonic acid--a primary metabolite of glyphosate) and of a more complex mixture of herbicides (glyphosate/AMPA/mecoprop/acetochlor/2,4D) were explored on the molecular and physiological responses of the European flounder Platichthys flesus, considering a long-term and environmentally realistic contamination. Molecular responses were identified using suppression subtractive hybridization on liver samples: the level of gene transcription was significantly different between contaminated fishes vs control ones for 532 sequences, after a 62-day contamination. Among them, 222 sequences were identified by homology with data-based sequences; they encoded several metabolic pathways including: methionine and lipid metabolism, immunity, protein regulation, coagulation and energetic metabolism. Expression pattern of nine transcripts in the liver was confirmed by real-time PCR. The molecular study underlined that potential markers of liver injury were expressed for both mixtures, in particular betaine homocysteine methyl transferase and chemotaxin. Physiological responses were analysed considering blood parameters and condition factor; after the two months contamination period; no significant physiological difference was detected between contaminated and control fish.|/AQUATIC SPECIES/ In the present study DNA damage was evaluated in the Chinese toad using the comet assay, as a potential tool for the assessment of ecogenotoxicity. ... Negative effects on the behavior of tadpoles were observed with acetochlor, butachlor, and paraquat. ... The comet assay was used for detecting DNA damage in Chinese toad tadpoles exposed to sublethal concentrations of four herbicides. Significant (P < 0.05) concentration-dependent increase in DNA damage (as indicated by tail length, tail moment, olive tail moment) were observed from erythrocytes of tadpoles exposed to sublethal concentrations of acetochlor, butachlor, paraquat, and methyl methanesulfonate, except chlorimuron-ethyl. ...|/AQUATIC SPECIES/ In this study, expression profiles of thyroid hormone receptor alpha (tralpha), deiodinase (d1 and d2), malic enzyme (me), and sodium iodide symporter (nis) genes were determined in larval and adult rare minnow (Gobiocypris rarus) after exposure to different levels of acetochlor (20, 200, and 2000 ng/L) for 21 days, respectively. Furthermore, plasma thyroid hormones (THs) levels in adults were evaluated simultaneously. The results showed that d1, d2, me, and nis mRNA levels were significantly down-regulated in the larvae. Similar expression changes of these genes in female brains were found. However, in adult livers, these gene expressions had no significant effects, except the tralpha mRNA level significantly up-regulated. These results indicated that exposure to acetochlor could result in tissue-specific alternative expression of TH-related genes in adults. Moreover, the expression of d2 and me showed a positive correlation with plasma T(4) levels in female brains. Therefore, larval development and adult brain of rare minnow could be affected by acetochlor at environmentally relevant concentrations.|For more Ecotoxicity Excerpts (Complete) data for ACETOCHLOR (8 total), please visit the HSDB record page.

Acetochlor's production may result in its release to the environment through various waste streams; its use as a herbicide(1) will result in its direct release to the environment(SRC).

TERRESTRIAL FATE: Based on a classification scheme(1), Koc values ranging from 98.5(2) to 335(3) indicate that acetochlor is expected to have high to moderate mobility in soil(SRC). Volatilization of acetochlor from moist soil surfaces is not expected to be an important fate process(SRC) given an estimated Henry's Law constant of 2.7X10-10 atm-cu m/mole(SRC), based upon its vapor pressure, 1.67X10-7 mm Hg(4), and water solubility, 223 mg/L(5). Acetochlor is not expected to volatilize from dry soil surfaces(SRC) based upon its vapor pressure(4). Acetochlor was degraded 8 to 15% in a sandy loam over the course of a 48 day incubation period(6), indicating that biodegradation is an important environmental fate process in soil(SRC).|FIELD STUDIES: Acetochlor, present at 100 ug/0.5 mL acetone water solution and incubated (26/21 °C day/night temperature; 65% relative humidity; 16 hr photoperiod) in a commercial black mold soil, was degraded to 2-chloro-N-(2-ethyl-6-methylphenyl)acetamide; a half-life of 90 days was reported. Depending on soil type, temperature, and moisture content, field half-lives range between 7 and 203 days(1). Acetochlor was shown to leach in luvisol and calcisol soils from the Paris, France basin following rain events; however degradation products (ethanesulfonic acid and oxanillic acid) were detected as early as 7 days after field application. It was not detected below the 5-10 cm depth in the luvisol and below the 30-40 cm depth in the calisol when sampled at a later date(2).|AQUATIC FATE: Based on a classification scheme(1), Koc values ranging from 98.5(2) to 335(3) indicate that acetochlor is not expected to adsorb to suspended solids and sediment(SRC). Volatilization from water surfaces is not expected(4) based upon an estimated Henry's Law constant of 2.7X10-10 atm-cu m/mole(SRC), derived from its vapor pressure, 1.67X10-7 mm Hg(5), and water solubility, 223 mg/L(6). According to a classification scheme(7), an estimated BCF of 250(SRC), from its log Kow of 4.14(5) and a regression-derived equation(8), suggests the potential for bioconcentration in aquatic organisms is high(SRC), provided the compound is not metabolized by the organism(SRC). The half-life of acetochlor in a sewage sludge was determined to be 17.2 hours(9), indicating that biodegradation may be an important environmental fate process in water(SRC).|ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), acetochlor, which has a vapor pressure of 1.67X10-7 mm Hg at 29 °C(2), will exist in both the vapor and particulate phases in the ambient atmosphere. Vapor-phase acetochlor is degraded in the atmosphere by reaction with photochemically-produced hydroxyl radicals(SRC); the half-life for this reaction in air is estimated to be 2.6 hours(SRC), calculated from its rate constant of 5.0X10-11 cu cm/molecule-sec at 25 °C(SRC) that was derived using a structure estimation method(3). Particulate-phase acetochlor may be removed from the air by wet or dry deposition(SRC). An aqueous solution of acetochlor irradiated for 24 hours in a quartz reactor resulted in a light spectrum of the arch at 311-437 nm with the most intensive emission at 360 nm(4); therefore acetochlor may be susceptible to direct photolysis by sunlight(SRC).

The rate constant for the vapor-phase reaction of acetochlor with photochemically-produced hydroxyl radicals has been estimated as 5.0X10-11 cu cm/molecule-sec at 25 °C(SRC) using a structure estimation method(1). This corresponds to an atmospheric half-life of about 2.6 hours at an atmospheric concentration of 5X10+5 hydroxyl radicals per cu cm(1). Acetochlor is expected to undergo hydrolysis in the environment due to the presence of functional groups that hydrolyze under environmental conditions(2); however hydrolysis is not an important environmental fate process(SRC). Hydrolysis has been described as first-order with half-lives in river water of 1386, 2310 and 2310 days at pH 4, pH 7 and pH 10, respectively(3).|Acetochlor was irradiated by UV-light in both methanol and water-methanol solvent mixtures(1). The photodecomposition of acetochlor was found to obey first order kinetics with a half-life of 1.2 hours in the water-methanol mixture while the half-life in pure methanol was measured at 0.5 hours(1). Acetochlor samples of 20 ug/L initial concentration were added to treatments containing 20 mg/L of nitrate-N and 1 mg/L of octanol and then irradiated for 155 minutes(2). The second-order rate constant for this reaction of acetochlor with OH radicals was determined to be 7.5X10+9 per M/second; summer-time half-lives based on this rate constant were estimated to be between the range of 1 to 20 days for the Blue Earth River in Minnesota(2). Acetochlor at 1% w/v in a 20% ethanol-water mixture was irradiated for 24 hours in a quartz reactor; the light spectrum of the arch was 311-437 nm with the most intensive emission at 360 nm. Photoproducts included N-(2-ethyl-6-methylphenyl)formamide, 2-chloro-N-(2-ethyl-6-methylphenyl)acetamide, N-(ethoxymethyl)-N-(2-ethyl-6-methylphenyl)acetamide, and 2-chloro-N-(2-ethyl-6-methylphenyl)-N-(propyloxymethyl)acetamide(3).

An estimated BCF of 250 was calculated in fish for acetochlor(SRC), using a log Kow of 4.14(1) and a regression-derived equation(2). According to a classification scheme(3), this BCF suggests the potential for bioconcentration in aquatic organisms is high(SRC), provided the compound is not metabolized by the organism(SRC).

208.93 L/kg|The Koc of acetochlor has been reported as 98.5(1), 239(2), log 2.30 (Koc = 199)(3), and 165(4). Using a silty clay loam, a Koc of 335 was reported(5). According to a classification scheme(6), this range of Koc values suggests that acetochlor is expected to have high to moderate mobility in soil. The leaching potential of acetochlor was assessed to be marginal based on a Koc value of 165 mL/g and a half-life in soil of 12 days(4). Freundlich adsorption coefficients of 7.9 and 4.8 were reported using Chinese agricultural soils - Beijing (pH 8.4; 1.5% organic carbon; cation exchange capacity 84 mmol/100 g; 59% sand; 38% silt; 3% clay) and Hebei (pH 7.7; 0.8% organic carbon; cation exchange capacity 215.4 mmol/100 g; 73% sand; 22% silt; 5% clay)(7). Using a soil inoculum from an agricultural field of Northwestern Beijing, China (pH 8.4; 1.5% organic carbon; cation exchange capacity 84.0 mmol/100 g; 59% silt; 38% sand; 3% clay), a mean Freundlich adsorption coefficient of 4.339 L/kg was measured(8).

The Henry's Law constant for acetochlor is estimated as 2.7X10-10 atm-cu m/mole(SRC) derived from its vapor pressure, 1.67X10-7 mm Hg(1), and water solubility, 223 mg/L(2). This Henry's Law constant indicates that acetochlor is expected to be essentially nonvolatile from water and moist soil surfaces(3). Acetochlor is not expected to volatilize from dry soil surfaces(SRC) based upon its vapor pressure(1).

GROUNDWATER: Acetochlor was detected in 1 out of 106 municipal wells sampled during the Summer of 1995 in Iowa, with a maximum measured concentration of 0.77 ug/L(1). Acetochlor was detected in water samples collected from 88 municipal wells throughout Iowa during the summer of 1996, a median value of summed concentration levels was <0.05 ug/L(2). Nationwide (US), acetochlor had a 0.09% frequency of detection in the 1064 sites where it was tested for, with a maximum detection of 0.023 ug/L, as part of a National Water Quality Assessment of groundwater conducted from 1992-1996 in 20 major hydrologic basins(3). A survey of Wisconsin groundwater at 336 sampling locations conducted between October 2000 and April 2001 revealed mean acetochlor metabolites ethane sulfonic acid and oxanillic acid concentrations of 0.15 and 1.8 ug/L, respectively(4).|SURFACE WATER: Acetochlor was detected in 35% of the samples taken from 52 Midwestern streams during 1994 at a median concentration of <0.05 ug/L(1). Acetochlor was detected in 84% of the samples taken from 50 Midwestern streams during 1995 at a median concentration of 0.42 ug/L(1). Acetochlor was detected in weekly composited rain and river water samples from near Frost, MN during the spring and early summer of 1994 at concentrations ranging from approximately 25 to 275 ug/L and 25 to 175 ug/L, respectively(2). Acetochlor was detected in the Patuxent River, a tributary of the Chesapeake Bay, in 1995 at a mean concentration level of 19 ng/L and between the range of <0.035 to 120 ng/L(3). Acetochlor was detected in surface water samples collected monthly from March through December 1996 at 12 sites in Eastern Iowa at a median summed concentration value of 0.06 ug/L(4). Similarly, acetochlor was detected in 17% of stream samples from 51 sites across nine mid-western states during 1994, with concentration values ranging from <0.05 ug/L to 1.2 ug/L. Acetochlor was detected in 78% of 375 samples collected at 32 stream sites in the Mississippi River Basin during the growing season of 1997 at concentrations ranging from non-detectable to 7.2 ug/L; however, concentrations exceeded 1 ug/L in only 5% of the samples(5). The compound was detected in one of 34 sites during a basin-wide sampling in August 1999 of the Yakima River Basin, Washington state(6). Acetochlor was tested for, not detected in a survey of North Carolina surface waters conducted over a 16 month period beginning in March 1996; detection limit = 0.01 ug/L(7). The annual load into the Chesapeake Bay from the Susquehanna River water shed is 200 kg/yr with a maximum daily load of 10 kg/day, based on water samples collected at the Conowingo Dam near the mouth of the river every 9 days from February 1997 through March 1998. Acetochlor exhibited a 56% detection, maximum concentration of 99 ng/L, average concentration of 11 ng/L(8). A mean acetochlor concentration of 0.55 ng/L (range of not detected to 1.50 ng/L) was reported in water samples from the Beijing Guanting Reservoir, China, sampled in September, November 2003 and June, August 2004(9). Throughout the US Corn Belt region (Ohio River Basin; Upper Mississippi River Basin; Missouri River Basin), acetochlor concentration trends were generally consistent with use trends for the years 1996-2002 and 2000-2006(10).|RAIN/SNOW/FOG: Acetochlor was detected in 29% of rain water samples collected from 4 sites in Iowa in 1994, with concentration values ranging from <0.05 ug/L to 2.5 ug/L(1). The average concentration of acetochlor (17% detection) in rain was 2.1, 6.6, 20, and 11.2 ng/L in 2000, 2001, 2002, and 2003, respectively, in samples taken in the Choptank River watershed of the Chesapeake Bay on the Delmarva Peninsula; detection limit = 1.30 ng/L(2). In a survey of rainfall in Mississippi urban and agricultural areas during April through September 1995, acetochlor exhibited a frequency of detection of 8% and 0% in samples from Jackson and Rolling Rock, MS, respectively; 47 and 44% frequency of detection in samples from Minneapolis, and Princeton, MN, respectively, and 7% frequency of detection in Eagle Harbor, MI. The average acetochlor concentration was 0.36 ug/L with a maximum of 1.6 ug/L(3).

Occupational exposure to acetochlor may occur through inhalation and dermal contact with this compound at workplaces where acetochlor is produced or used. Monitoring data indicate that the general population residing in the US Corn Belt may be exposed to acetochlor via dermal contact with contaminated water and rainfall. (SRC)

Pesticides used to destroy unwanted vegetation, especially various types of weeds, grasses (POACEAE), and woody plants. Some plants develop HERBICIDE RESISTANCE. (See all compounds classified as Herbicides.)

Acetochlor is rapidly and almost entirely absorbed (>80% in 48hr). It is widely distributed in well perfused organs and shows a low potential for bioaccumulation. There is some accumulation in nasal turbinates in rats but not in mice. The elimination occurs mainly via urine (66-72% in 48hr) and feces (12-21% in 48hr, from which 80-85% is eliminated through bile).|Absorbed mainly by germinating plant shoots, secondarily by roots. Translocation ... throughout the plant, with higher concentrations in vegetative parts than in reproductive parts.

The main pathway of metabolism is the glutathione conjugation and further mercapturic acid pathway and glucuronidation. ...|... /Researchers/ positively identified acetochlor mercapturate (ACM) as a metabolite of acetochlor in urine samples collected during a 24 hr period from custom (commercial) applicators who had applied acetochlor on either the day of or the day before urine collection. Concentrations in applicator urine samples ranged from 0.5 to 449 ug/L (0.3-121 ug/g creatinine). ... /Investigators/ found that ACM accounted for as much as 42% of the total acetochlor-derived metabolites; however, as the exposure level decreased (based on total acetochlor metabolite level), ACM became a less abundant metabolite of acetochlor (<17%). Unmetabolized acetochlor was also measured in the urine samples analyzed. At high exposures (classified as >100 ug/L), acetochlor accounted for about 0.8% of the total excreted acetochlor metabolites (approximately 2% of the ACM concentrations). At lower exposures (classified as ACM<10 ug/L), ACM and acetochlor concentrations were similar. Additionally, we tentatively identified another acetochlor metabolite that appeared to be important at low levels of exposure.|Acetachlor has known human metabolites that include 2-Chloro-N-(2-ethyl-6-methylphenyl)acetamide and N-(Ethoxymethyl)-2-ethyl-6-methylaniline.

Skin decontamination: Skin contamination should he treated promptly by washing with soap and water. Contamination of the eyes should be treated immediately by prolonged flushing of the eyes with large amounts of clean water. If dermal or ocular irritation persists, medical attention should be, obtained without delay. /Herbicides/|Gastrointestinal decontamination: Ingestion of these herbicides are likely to be followed by vomiting and diarrhea due to their irritant properties. Management depends on: (1) the best estimate of the quantity ingested, (2) time elapsed since ingestion, and (3) the clinical status of the subject. Activated charcoal is probably effective in limiting irritant effects and reducing absorption of most or all of these herbicides. Aluminum hydroxide antacids may be useful in neutralizing the irritant actions of more acidic agents. Sorbitol should be given to induce catharsis if bowel sounds are present and if diarrhea has not already commenced. Dehydration and electrolyte may be severe enough to require oral or intravenous fluids. There are no specific antidotes for poisoning by these herbicides. In the case of suicidal ingestions, particularly, the possibility must always be kept in mind that multiple toxic substances may have been swallowed. If large amounts of herbicide have been ingested and the patient is seen an hour of the ingestion, gastrointestinal decontamination should be considered. If the amount of ingested herbicides was small, if effective emesis has already occurred, or if treatment is delayed, administer activated charcoal and sorbitol mouth. /Herbicides/|Intravenous fluids: If serious dehydration and electrolyte depletion have occurred as a result of vomiting and diarrhea, monitor blood electrolytes and fluid balance and administer intravenous infusions of glucose, normal saline, Ringer's solution, or Ringer's lactate to restore extracellular fluid volume and electrolytes. Follow this with oral nutrients as soon as fluids can be retained. /Herbicides/|/SRP:/ Immediate first aid: Ensure that adequate decontamination has been carried out. If patient is not breathing, start artificial respiration, preferably with a demand valve resuscitator, bag-valve-mask device, or pocket mask, as trained. Perform CPR if necessary. Immediately flush contaminated eyes with gently flowing water. Do not induce vomiting. If vomiting occurs, lean patient forward or place on the left side (head-down position, if possible) to maintain an open airway and prevent aspiration. Keep patient quiet and maintain normal body temperature. Obtain medical attention. /Poisons A and B/|For more Antidote and Emergency Treatment (Complete) data for ACETOCHLOR (6 total), please visit the HSDB record page.

/SURVEILLANCE/ Biomonitoring was used to assess the combined dermal, oral, and inhalation exposure associated with the agricultural use of Harness Plus, an emulsifiable concentrate formulation of the herbicide acetochlor. Twenty Spanish farmers handled and applied acetochlor to maize in the spring of 2003, following the product label recommendations. Open- and closed-cabin applications were equally represented. Urine was collected during six consecutive days, starting the day prior to application. Daily composites were analyzed for 2-ethyl-6-methyl-aniline, a common chemophore representing the major urinary acetochlor metabolites. All applicators showed detectable concentrations in urine after application. Although, the open-cabin applicators treated fewer hectares, they showed significantly higher exposure compared to the closed-cabin applicators (average exposure: 0.004 and 0.002 mg/kg bw/day, respectively). Linear regression analysis suggested that untracked incidents had a significant impact on the total exposure. Other events that may have contributed to the observed exposure are repair of faulty equipment, accidental spillages, splashes, and inadequate use of protective gloves. The average margins of exposure (MOE) for farmers ranged from 23,000 (open cabin) to about 44,000 (closed cabin). For professional applicators the MOEs were 10-fold lower. ...|/GENOTOXICITY/ ... Acetochlor is clastogenic to human lymphocytes in vitro at cytotoxic dose levels. The nonclastogenicity of the deschloro analog of acetochlor is the clastogenic moiety. Although relatively inert, this substituent can react with sulfhydryl (-SH) groups such as that present on reduced glutathione.|/ALTERNATIVE and IN VITRO TESTS/ ... Cytotoxicity of the three chloroacetanilides, /alachlor (2-chloro-2',6'-diethyl-N-(methoxymethyl)-acetanilide), acetochlor (2-chloro-2'-methyl-6'-ethyl-N-(ethoxymethyl)acetanilide), and metolachlor (2-chloro-2'-ethyl-6'-methyl-N-(1-methyl-2-methoxymethyl)acetanilide)/, was ranked using isolated rat and cryopreserved human hepatocytes to correlate this endpoint with CYP3A-dependent metabolism. Chloroacetanilide cytotoxicity in rat hepatocyte suspensions was time dependent... . Alachlor and acetochlor were more potent than metolachlor after 2 and 4 hr, times when N-dealkylated alachlor product 2-chloro-N-(2,6-diethylphenyl)acetamide (CDEPA) formation was readily detectable. Alachlor and acetochlor potencies with cryopreserved human hepatocytes at 2 hr were comparable to freshly isolated rat hepatocytes, and alachlor metabolism to CDEPA was likewise detectable. Unlike rat hepatocytes, metolachlor potency was equivalent to acetochlor and alachlor in human hepatocytes. Furthermore, chloroacetanilide cytotoxicity from two sources of human hepatocytes varied inversely with CYP3A4 activity. Collectively, while cytotoxicity in rat hepatocytes was consistent with chloroacetanilide activation by CYP3A, an activating role for CYP3A4 was not supported with human hepatocytes.|/ALTERNATIVE and IN VITRO TESTS/ We tested the interaction of the herbicides acetochlor, alachlor, dimetachlor, metazachlor, metolachlor, propachlor and prynachlor with human multidrug resistance transporters MDR1, MRP1, MRP2 and BCRP. A number of metabolites were studied for interaction with MRP1, MRP2 and MRP3. Transporter interactions were studied by measuring ATPase activity, inhibition of fluorescent dye efflux and vesicular transport. Also inhibition of MDR1 was monitored by measuring digoxin transport on Caco-2 monolayers and paclitaxel toxicity on K562-MDR cells. Acetochlor, alachlor, metolachlor and metazachlor showed specific interactions with MDR1. Digoxin permeability and paclitaxel cytotoxicity studies revealed that these herbicides are potent inhibitors of MDR1 that can modulate drug absorption and cause chemosensitization of cells. MRP1 was demonstrated to transport an important intermediate of the acetochlor detoxification pathway. Several specific interactions were shown when studying the interaction of chloroacetanilides with human transporter proteins. ...|/OTHER TOXICITY INFORMATION/ ... /The/ aim was to study the putative preventive effect of RESV /trans-resveratrol/ on the cytotoxicity of frequently used herbicides (alachlor, acetochlor). Estrogen receptor positive (ER+) MCF-7 human mammary carcinoma, HepG2 (ER+) human hepatocellular carcinoma and VERO estrogen receptor negative (ER-) non-transformed monkey fibroblast cell lines were treated with alachlor and acetochlor (2-500 ug/mL) as toxic agents, and RESV (10 uM) as preventive agent. The MTT dye reduction assay was performed to test cytotoxicity, and flow cytometry to test cell proliferation and apoptosis. RESV is not cytotoxic in the concentration range of 1-100 uM on neither cell lines examined after 24 hr, but cytotoxic on Vero and MCF-7 cells at 100 uM after 48hr, and on all three cell lines after 72 hr. On both ER+ cell lines a stimulation of viability occurs in the low concentration range (0.5-12.5 uM) as detected by the MTT assay. Cell cycle analysis of the culture shows a significant increase of S-phase cells at low concentrations of RESV (10-50 uM) and a decrease in the 100-200 uM concentration range. The ratio of apoptotic cells significantly increases after the administration of 50 uM RESV, depending on the incubation time. The cytotoxicity of 20-65 ug/mL alachlor and 10-65 ug/mL acetochlor was significantly decreased by the addition of 10 uM RESV in Vero ER- cells whereas no significant change was detected on ER+ cell lines MCF-7 and HepG2. These results show that RESV protects non-transformed ER- cells, but has no such effect on ER+ tumor cells.

acetochlor

Quantity used in US agricultural crop protection in 1995: 10 to 12.3X10+6 kg

USEPA/OPP Pesticide Code 121601; Trade Names: MON 097; CP 55097; Harness.|Emulsifiable concentrate, granule, microencapsulate.|Premix Partners: Atrazine; Bensulfuron-methyl; Clopyralid; EPTC: Flumetsulam; Flurochloridone; Oxyfluorfen; Quizalofop-P-ethyl; Terbuthylazine.|Doubleplay Selective Herbicide (Syngenta Crop Protection, LLC): EPTC 67.8%, Acetochlor 16.9%.|For more Formulations/Preparations (Complete) data for ACETOCHLOR (45 total), please visit the HSDB record page.

The WHO Recommended Classification of Pesticides by Hazard identifies acetochlor (technical grade) as Class III: slightly hazardous; Main Use: herbicide.

Method: Abraxis 500021; Procedure: immunoassay, magnetic particle; Analyte: acetochlor; Matrix: water; Detection Limit: 0.04 ppb.|Method: EPA-NERL 525.2; Procedure: gas chromatography/mass spectrometry; Analyte: acetochlor; Matrix: finished drinking water, source water, or drinking water in any treatment stage; Detection Limit: not provided.|Method: EPA-OGWDW/TSC 526; Procedure: gas chromatography/mass spectrometry; Analyte: acetochlor; Matrix: raw water and finished drinking water; Detection Limit: 0.015 ug/L.|Method: USGS-NWQL O-1126-95; Procedure: gas chromatography-mass spectrometry with select-ion monitoring; Analyte: acetochlor; Matrix: natural water; Detection Limit: 0.0015 ug/L.|Product by glc. Residues in crops and animal products determined by hydrolysis and gc ... Analysis in water determined by gc-ms, or by gc with ECD ... Residues in soil by gc/ms or gc with ECD or NPD.

Agrochemicals -> Herbicides