Chlorimuron-ethyl

414.82

414.82

618-690-2

B00AW0IM5Q

DTXSID0023955

Crystals from butyl chloride|White solid|Colorless crystals

2935009012

144.96000

3.37040

Chlorimuron ethyl appears as colorless crystals. Used as an herbicide.

1.493 g/cm3

198-201 °C

1.598

Freely soluble in aqueous solution

0-6°C

4.0X10-12 mm Hg at 25 deg C

LD50 in male, female rats (mg/kg): 4102, 4236 orally (Claus)

Henry's Law constant = 1.82X10-15 atm-cu m/mol at 25 °C, pH 7 (est)

pKa = 4.20

Hydroxyl radical reaction rate constant = 4.27X10-11 cu cm/molec-sec at 25 °C (est)

No rapid reaction with air. No rapid reaction with water.

Amines, Phosphines, and Pyridines

CHLORIMURON ETHYL is a sulfonyl urea, and pyrimidine derivative.

NONH for all modes of transport

36

26-36

DG5095000

Xi

P260, P261, P271, P273, P304+P312, P304+P340, P312, P314, P391, P501

H332

SRP: The most favorable course of action is to use an alternative chemical product with less inherent propensity for occupational exposure 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, aquatic, and plant life; and conformance with environmental and public health regulations.|May be dispose of on-site or at an approved waste disposal facility. Container disposal: triple rinse (or equivalent), then offer for recycling or reconditioning or puncture and dispose of in sanitary landfill or incinerate if allowed by state and local authorities, by burning. If burned stay out of smoke.|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.|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. Do cut or puncture other empty pesticide containers made of metal or plastic to prevent someone from reusing them. Wrap the empty container and put it in the trash after you have rinsed it.

|Warning|H332 (52.05%): Harmful if inhaled [Warning Acute toxicity, inhalation]|P260, P261, P271, P273, P304+P312, P304+P340, P312, P314, P391, and P501|Aggregated GHS information provided by 73 companies from 6 notifications to the ECHA C&L Inventory. Each notification may be associated with multiple companies.

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.|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.

Avoid contact with skin, eyes or clothing. Wash contaminated clothing with soap and hot water before reuse.|SRP: Contaminated protective clothing should be segregated in such a manner so that there is no direct personal contact by personnel who handle, dispose, or clean the clothing. Quality assurance to ascertain the completeness of the cleaning procedures should be implemented before the decontaminated protective clothing is returned for reuse by the workers. Contaminated clothing should not be taken home at end of shift, but should remain at employee's place of work for cleaning.|Wear the items of protective clothing the label requires: for example, non-absorbent gloves (not leather or fabric), rubber footwear (not canvas or leather), a hat, goggles, or a dust-mist filter. If no specific clothing is listed, gloves, long-sleeved shirts and long pants, and closed shoes are recommended. You can buy protective clothing and equipment at hardware stores or building supply stores.|Outdoor Applications. Never apply pesticides outdoors on a windy day (winds higher than 10 mph). Position yourself so that a light breeze does not blow pesticide spray or dust into your face.

It is a mild eye and skin irritant and does not cause skin sensitization.

The average (maximum) runoff of chlorimuron-ethyl from 3 treated farm plots in Maryland over a 3 year period ranged from 0.025-0.17 ug/L(0.34-2.96 ug/L) for field A, 0.18-1.08 ug/L (5-25.3 ug/L) for field B, and 0.07-0.18 ug/L (0.29-0.47 ug/L) for field C(1).

BAS 145 138 protected corn from injury due to low levels of chlorimuron ethyl. Inhibition of root growth was used to monitor injury. BAS 145 138 did not affect uptake, but it caused a two fold increase in the rate of chlorimuron ethyl metabolism in corn roots and shoots. The increase in chlorimuron ethyl metabolism was correlated positively to growth. Routes of metabolism that were accelerated in response to BAS 145 138 included hydroxylation of chlorimuron ethyl at the 5-position of the pyrimidine ring, the formation of the corresponding glucoside, the formation of two glutathione conjugates, and the formation of two unidentified metabolites. The most dramatic of the effects was on the formation of the glucoside of 5-hydroxychlorimuron ethyl. In the roots, the level of this metabolite was increased six fold in response to BAS 145 138. Part of this increase was due to an elevation in the in vivo rate of glucosylation of 5-hydroxychlorimuron ethyl. BAS 145 138 did not alter the qualitative routes of chlorimuron ethyl metabolism, nor did it appear to affect the levels or catalytic properties of acetolactate synthase, the target enzyme of chlorimuron ethyl. 5-Hydroxychlorimuron ethyl was 152 times less effective as an inhibitor of acetolactate synthase than chlorimuron ethyl. The glucoside of 5-hydroxychlorimuron ethyl was hydrolyzed during the acetolactate synthase assay; therefore, an I50 value for this metabolite was not obtained.

LC50 Rat inhalation >5 mg/L/4 hr|LD50 Rabbit dermal > 2000 mg/kg|LD50 Rat oral >5000 mg/kg

Chlorimuron-ethyl's production may result in its release to the environment through various waste streams(SRC); its use as a post-emergence herbicide for soya beans and peanut crops(1) will result in its direct release to the environment(SRC).

TERRESTRIAL FATE: Based on a classification scheme(1), Koc values in the range of 30 to 170 measured in 4 soils(2), indicates that chlorimuron-ethyl is expected to have high to very high mobility in soil(SRC). Volatilization of chlorimuron-ethyl from moist soil surfaces is not expected to be an important fate process(SRC) given an estimated Henry's Law constant of 1.8X10-15 atm-cu m/mole (SRC) derived from its vapor pressure, 4X10-12 mm Hg(2), and water solubility, 1,200 mg/L(3). Chlorimuron-ethyl is not expected to volatilize from dry soil surfaces(SRC), based upon its vapor pressure(2). Chlorimuron-ethyl has a reported half-life in soil of 53 days under aerobic conditions(2). The photolysis half-life of chlorimuron-ethyl applied to a soil (pH 5.8) was approximately 36 days(2).|TERRESTRIAL FATE: The biodegradation half-life of chlorimuron-ethyl in a sandy loam and a silt loam maintained under aerobic conditions was reported as 53 days(1). The terrestrial field dissipation half-life of chlorimuron-ethyl was <14 days, <14 days, 28-42 days, and 14-28 days when applied to fields located in Fayetteville, NC, Stoneville, MS, Rochelle, IL, and Newark, DE, respectively(1).|AQUATIC FATE: Based on a classification scheme(1), Koc values in the range of 30 to 170 measured in soil(2), indicate that chlorimuron-ethyl is not expected to adsorb to suspended solids and sediment(SRC). Volatilization from water surfaces is not expected(3) based upon an estimated Henry's Law constant of 1.8X10-15 atm-cu m/mole (SRC) derived from its vapor pressure, 4X10-12 mm Hg(2), and water solubility, 1,200 mg/L(4). According to a classification scheme(5), an estimated BCF of 17(SRC), from its log Kow of 2.50(6) and a regression-derived equation(7), suggests the potential for bioconcentration in aquatic organisms is low(SRC). The aqueous hydrolysis half-life of chlorimuron-ethyl at 25 °C is approximately 17 days at pH 5 and less than 3.5 days at pH 7-9(2), and the aqueous photolysis half-life at pH 5 and 25 °C is approximately 12 days(1) although hydrolysis may be contributing to the dergadation.|ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), chlorimuron-ethyl, which has a measured vapor pressure of 4X10-12 mm Hg at 25 °C(2), will exist solely in the particulate phase in the ambient atmosphere. Particulate-phase chlorimuron-ethyl may be physically removed from the air by wet and dry deposition(SRC).

The hydrolysis rate constant for chlorimuron-ethyl was reported as 0.041 days-1 at pH = 5 and <0.2 days-1 at pH 7 and 9(1). This corresponds to hydrolysis half-lives of approximately 17 days at pH 5 and less than 3.5 days at pH 7-9(SRC). The aqueous photolysis rate constant of chlorimuron-ethyl at pH 5 and 25 °C was reported as 0.058 days-1(1); corresponding to a half-life of approximately 12 days(SRC). The photolysis rate constant of chlorimuron-ethyl applied to a soil surface (pH 5.8) was 0.0194 days-1(1); corresponding to a half-life of approximately 36 days(SRC).

An estimated BCF value of 17 was calculated in fish for chlorimuron-ethyl(SRC), using a measured log Kow of 2.50(1) and a regression-derived equation(2). According to a recommended classification scheme(3), this BCF value suggests the potential for bioconcentration in aquatic organisms is low(SRC).

109.65 L/kg|The Koc of chlorimuron-ethyl ranged from 30 in a sandy loam (pH 6.6, 1.1% organic matter) to 170 in a silt loam (pH 5.2, 7.5% organic matter)(1). According to a classification scheme(2), these Koc values indicate that chlorimuron-ethyl is expected to have high to very high mobility in soil(SRC).

The Henry's Law constant for chlorimuron-ethyl is estimated as 1.8X10-15 atm-cu m/mole(SRC) from its experimental values for vapor pressure, 4X10-12 mm Hg(1), and water solubility, 1,200 mg/L(2). This value indicates that chlorimuron-ethyl will be essentially nonvolatile from water and moist soil surfaces(SRC). Chlorimuron-ethyl is not expected to volatilize from dry soil surfaces(SRC) based upon its vapor pressure(1).

SURFACE WATER: The maximum concn of chlorimuron-ethyl measured in 129 water samples from streams and rivers obtained in the Midwestern United States in 1998 was 0.304 ug/L(1).

Occupational exposure to chlorimuron-ethyl may occur through dermal contact with this compound at workplaces where chlorimuron-ethyl is produced or used. The general population may be exposed to chlorimuron-ethyl via ingestion of contaminated drinking water. (SRC)

The compound /chlorimuron-ethyl/ is absorbed from the gastrointestinal tract and is eliminated equally in urine and feces with a biological half-life of about 50 hours. Chlorimuron-ethyl is distributed throughout the body, with the largest portions found in the liver.

Chlorimuron-ethyl was ...extensively metabolized by both male and female rats at the low and high dose. Excretion was monitored up to 168 hrs and the elimination of radioactivity was equal via the urine and feces for the low and high dose. The half-life is 50 hrs. /Five/... major metabolites .../were found/.|(14)C Chlorimuron ethyl was readily absorbed by the roots of young intact corn seedlings and through the cut ends of excised leaves, but it was not readily absorbed by intact leaves. Under the conditions employed, (14)C-chlorimuron ethyl was metabolized at a moderate rate in both intact roots and excised leaves (ca 2.4 nmol/g fresh weight tissue/hr). Based upon HPLC analysis, (14)C-chlorimuron ethyl appeared to be metabolized by similar routes in both the roots and leaves. (14)C Chlorimuron ethyl and 10 radioactive metabolites were detected in the roots of corn 7 hr following herbicide treatment. (14)C-Chlorimuron ethyl and the following metabolites, listed in approximate order of their abundance, were isolated and characterized: chlorimuron ethyl (N-(4-chloro-6-methoxypyrimidine-2-yl)-N'-(2-ethoxycarbonylbenzene-sulfonyl)urea; N-(4-chloro-5-hydroxy-6-methoxypyrimidine-2-yl)-N'-(2-ethoxy carbonylbenzenesulfonyl)urea, 2-ethoxycarbonylbenzene sulfonamide, N-(4-(S-glutathionyl)-6-methoxypyrimidine-2-yl)-N'-(2-etho xycarbonyl benzenesulfonyl)urea, N-(4-(S-glutathionyl)-5-hydroxy-6-methoxypyrimidine-2-yl)- N'-(2- ethoxycarbonylbenzenesulfonyl)urea, N-(4-chloro-5-(O-beta-D-glucosyl)-6-methoxypyrimidine-2-yl)-N'ethoxy carbonylbenzenesulfonyl)urea, and N-(4-(S-cysteinyl)-6-methoxypyrimidine-2-yl)-N'-(2-ethoxycarbonyl- benzenesulfonyl)urea. Chlorimuron ethyl and these metabolites were purified by HPLC and were characterized by fast atom bombardment mass spectrometry. In addition to fast atom bombardment mass spectrometry, the following methods were used in the characterization of some metabolites: synthesis, hydrolysis with beta-glucosidase, analysis of hydrolysis products, electron impact MS, and proton nuclear magnetic resonance (400 MH).

About 50 hours

Sulfonylurea class herbicide that inhibits acetolactate synthase, which regulates plant growth.|Branched chain amino acid synthesis (ASL or AHAS) inhibitor. Acts by inhibiting biosynthesis of the essential amino acids valine and isoleucine, hence stopping cell division and plant growth. Crop selectivity derives from plant metabolism both by homoglutathione conjugation and by de-esterification.|...Acetolactate synthase /is/ the target enzyme of chlorimuron ethyl.

Skin decontamination. Skin contamination should be 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. /Other herbicides/|Gastrointestinal decontamination. Ingestions 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 spontaneous diarrhea has not already commenced. Dehydration and electrolyte disturbances may be severe enough to require oral or intravenous fluids. ... If large amounts of herbicide have been ingested and the patient is seen within 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 by mouth. /Other 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. /Other herbicides/|Supportive measures are ordinarily sufficient for successful management of excessive exposures to these herbicides ... . If the patient's condition deteriorates in spite of good supportive care, the operation of an alternative or additional toxicant should be suspected. /Other herbicides/|For more Antidote and Emergency Treatment (Complete) data for CHLORIMURON-ETHYL (6 total), please visit the HSDB record page.

/EPIDEMIOLOGY STUDIES/ ...Eight of 16 herbicides were associated with wheeze /among 2,255 Iowa commercial pesticide applicators enrolled in the Agricultural Health Study/ in single-agent models; the risk was almost exclusively associated with the herbicide chlorimuron-ethyl (odds ratio (OR) = 1.62, 95% confidence interval (CI): 1.25, 2.10). Inclusion of chlorimuron-ethyl in models for the other herbicides virtually eliminated the associations. The odds ratios for four organophosphate insecticides (terbufos, fonofos, chlorpyrifos, and phorate) were elevated when these chemicals were modeled individually and remained elevated when chlorimuron-ethyl was included. The association for dichlorvos was not attenuated by chlorimuron-ethyl (OR = 2.48, 95% CI: 1.08, 5.66). Dose-response trends were observed for chlorimuron-ethyl, chlorpyrifos, and phorate; the strongest odds ratio was for applying chlorpyrifos on more than 40 days per year (OR = 2.40, 95% CI: 1.24, 4.65).

chlorimuron ethyl

May be applied ... by band treatment, broadcast, ground spray, low volume spray, or soil incorporated treatment at the current maximum application rate of 0.0825 lbs active ingredient per acre (per crop cycle)(soybean); by band treatment, broadcast, or low volume spray at the current maximum application rate of 0.0078125 lbs active ingredient per acre (per crop cycle) (peanut); by broadcast at the current maximum application rate of 0.03125 lbs active ingredient per acre (non-crop land at foliar stage)

Discontinued Trade names: Concert, Gemini, Lorox Plus, Mulexyl, Preview, Reliance, STS, Skermish.|Chlorimuron-ethyl is produced as a water dispersible granular formulation (WDG) and registration is pending for a granular formulation. The active ingredient (ai), chlorimuron-ethyl, ranges from 8.3 to 31.8% in the registered end-use formulations.|Dry formulation

Selective sulfonylurea herbicide|There are no residential uses

Pyrolysis GC/MS and electron impact fast atom bombardment-MS chlorimuron-ethyl was performed.|Method: USGS-NWQL O-2060-01; Procedure: graphitized carbon-based solid-phase extraction and high performance liquid chromatography/mass spectrometry; Analyte: chlorimuron-ethyl; Matrix: water; Detection Limit: 0.0048.|Product analysis by hplc ... Residues determined by hplc.