Chlorsulfuron

357.77

357.77

265-268-5

O6S620ML45

3077|2588

DTXSID7023980

White crystalline solid|Crystals from ether

2935009011

132

0.74 at pH 5

Colorless crystals.

1.5±0.1 g/cm3

174-178 °C

563ºC

1.617

>53.7 [ug/mL]

0-6°C

2.25X10-11 mm Hg at 25 deg C

LD50 in male, female rats (mg/kg): 5545, 6293 orally (Levitt)

Odorless

Henry's Law constant = 5X10-10 (pH 5); 2.5X10-11 (pH 7); 3.2X10-12 (pH 9) (all in Pa-cu m/mol, 20 °C)

pKa = 3.4

175.29 Ų [M+H]+ [CCS Type: TW]|179.87 Ų [M-H]-

Decomposition temperature: 192 °C

Insoluble in water. Reacts slowly with water. The reaction is promoted by acid such that the pH is less than 5.0 (1/2 life of 24-48 hrs.). Reaction is also promoted by polar organic solvents such as methanol and acetone.

Amides and Imides

Non-corrosive

UN30779/PG3

2

50/53

60-61-36-26

YS6640000

N,Xi

Stable to light when dry. In aqueous solutions, 50% hydrolysis occurs 4-8 weeks @ pH 5.7-7.0 and 20 deg C. Significant degradation occurs in 24-48 hr in acidic aqueous solutions below pH 5. Hydrolysis is also promoted by polar organic solvents such as methanol and acetone.

P273-P501

H410

SRP: 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 air, soil or water; effects on animal, aquatic and plant life; and conformance with environmental and public health regulations. If it is possible or reasonable use an alternative chemical product with less inherent propensity for occupational harm/injury/toxicity or environmental contamination.|Product: Offer surplus and non-recyclable solutions to a licensed disposal company; Contaminated packaging: Dispose of as unused product.

USEPA/Office of Prevention, Pesticides and Toxic Substances; Reregistration Eligibility Decision Document - Chlorsulfuron (May 2005). The RED summarizes the risk assessment conclusions and outlines any risk reduction measures necessary for the pesticide to continue to be registered in the USA.[Available from, as of June 20, 2017 http://www.epa.gov/pesticides/reregistration/status.htm]|Blair AM, Martin TD; Pestic Sci 22 (3): 195-220 (1988). A review of the activity fate and mode of action of sulfonylurea herbicides

Excerpt from ERG Guide 171 [Substances (Low to Moderate Hazard)]: Some may burn but none ignite readily. Containers may explode when heated. Some may be transported hot. For UN3508, be aware of possible short circuiting as this product is transported in a charged state. (ERG, 2016)

|Warning|H400: Very toxic to aquatic life [Warning Hazardous to the aquatic environment, acute hazard]|P273, P391, and P501|H400 (100%): Very toxic to aquatic life [Warning Hazardous to the aquatic environment, acute hazard]|Aggregated GHS information provided by 164 companies from 4 notifications to the ECHA C&L Inventory. Each notification may be associated with multiple companies.|H410: Very toxic to aquatic life with long lasting effects [Warning Hazardous to the aquatic environment, long-term hazard]

Excerpt from ERG Guide 171 [Substances (Low to Moderate Hazard)]: As an immediate precautionary measure, isolate spill or leak area in all directions for at least 50 meters (150 feet) for liquids and at least 25 meters (75 feet) for solids. SPILL: Increase, in the downwind direction, as necessary, the isolation distance shown above. FIRE: If tank, rail car or tank truck is involved in a fire, ISOLATE for 800 meters (1/2 mile) in all directions; also, consider initial evacuation for 800 meters (1/2 mile) in all directions. (ERG, 2016)

Excerpt from ERG Guide 171 [Substances (Low to Moderate Hazard)]: Do not touch or walk through spilled material. Stop leak if you can do it without risk. Prevent dust cloud. Avoid inhalation of asbestos dust. SMALL DRY SPILL: With clean shovel, place material into clean, dry container and cover loosely; move containers from spill area. SMALL SPILL: Pick up with sand or other non-combustible absorbent material and place into containers for later disposal. LARGE SPILL: Dike far ahead of liquid spill for later disposal. Cover powder spill with plastic sheet or tarp to minimize spreading. Prevent entry into waterways, sewers, basements or confined areas. (ERG, 2016)

Excerpt from ERG Guide 171 [Substances (Low to Moderate Hazard)]: Wear positive pressure self-contained breathing apparatus (SCBA). Structural firefighters' protective clothing will only provide limited protection. (ERG, 2016)|Eye/face protection: Use equipment for eye protection tested and approved under appropriate government standards such as NIOSH (US) or EN 166(EU).|Skin protection: Handle with gloves.|Body Protection: Choose body protection in relation to its type, to the concentration and amount of dangerous substances, and to the specific work-place.|Respiratory protection: Respiratory protection is not required. Where protection from nuisance levels of dusts are desired, use type N95 (US) or type P1 (EN 143) dust masks. Use respirators and components tested and approved under appropriate government standards such as NIOSH (US) or CEN (EU).|... Baseline attire (long sleeve shirt, long pants, shoes, and socks).

Suitable extinguishing media: Use water spray, alcohol-resistant foam, dry chemical or carbon dioxide.|Advice for firefighters: Wear self contained breathing apparatus for fire fighting if necessary.

ACCIDENTAL RELEASE MEASURES: Personal precautions, protective equipment and emergency procedures. Use personal protective equipment. Avoid dust formation. Avoid breathing vapors, mist or gas. Ensure adequate ventilation. Evacuate personnel to safe areas. Avoid breathing dust. Environmental precautions: Prevent further leakage or spillage if safe to do so. Do not let product enter drains. Discharge into the environment must be avoided. Methods and materials for containment and cleaning up: Pick up and arrange disposal without creating dust. Sweep up and shovel. Keep in suitable, closed containers for disposal.

ACCIDENTAL RELEASE MEASURES: Personal precautions, protective equipment and emergency procedures. Use personal protective equipment. Avoid dust formation. Avoid breathing vapors, mist or gas. Ensure adequate ventilation. Evacuate personnel to safe areas. Avoid breathing dust. Environmental precautions: Prevent further leakage or spillage if safe to do so. Do not let product enter drains. Discharge into the environment must be avoided.|Precautions for safe handling: Provide appropriate exhaust ventilation at places where dust is formed.|Appropriate engineering controls: Handle in accordance with good industrial hygiene and safety practice. Wash hands before breaks and at the end of workday.|Gloves must be inspected prior to use. Use proper glove removal technique (without touching glove's outer surface) to avoid skin contact with this product. Dispose of contaminated gloves after use in accordance with applicable laws and good laboratory practices. Wash and dry hands.|For more Preventive Measures (Complete) data for Chlorsulfuron (7 total), please visit the HSDB record page.

/SRP: Eye irritant/

IDENTIFICATION AND USE: Chlorsulfuron is a white crystalline solid. It is a selective preemergence or early postemergence herbicide used at low rates. HUMAN STUDIES: There are no data available. ANIMAL STUDIES: In 2 yr feeding trials, rats receiving 100 mg/kg diet and mice receiving 500 mg/kg diet showed no ill-effects. Developmental studies in rats demonstrated reduced maternal body weights and food consumption at 1500 mg/kg/day and decreased fetal body weights at 1500 mg/kg/day. There were no teratogenic effects. Chlorsulfuron tested negative for mutagenicity in Salmonella typhimurium bacterial strains TA98, TA100, TA1535, TA1537 treated for 48 hours with chlorsulfuron at 0, 0.001, 0.005, 0.01, 0.05, 0.1 or 0.5 ug/plate with or without metabolic activation. ECOTOXICITY STUDIES: Chlorsulfuron is practically non-toxic to birds and mammals on an acute exposure basis and is also practically nontoxic to birds on a subacute dietary exposure basis. Following chronic exposure, bobwhite quail exhibited significant reductions in female body weight, 14-day old survivors/normal hatchlings, viable embryos/eggs set, and 14-day hatchling survival/eggs set. Chlorsulfuron is also practically nontoxic to honeybees on an acute contact basis. Chlorsulfuron is practically nontoxic to both freshwater and estuarine/marine fish on an acute exposure basis and is slightly toxic to estuarine/marine invertebrates. Aquatic plant toxicity ranged from practically nontoxic to very highly toxic. Chlorsulfuron is toxic to nontarget terrestrial plants. Chlorsulfuron is a potent inhibitor of cell division and branched amino acid biosynthesis in plants.

Pea (Pisum sativum L. cv Alaska) root tips were excised and cultured aseptically in White's medium. Cultures were treated immediately or after a 24 hour equilibration time with 28 nanomolar chlorsulfuron plus isoleucine and valine (each 0.1 millimolar), isoleucine and valine, or untreated. The percentage of mitotic figures in untreated control roots sampled immediately after excision showed a transitory drop and recovery within 24 hours (an excision effect). In chlorsulfuron-treated roots, the percentage of mitotic figures did not recover. In roots treated with chlorsulfuron plus isoleucine and valine, a complete recovery did occur. If roots were treated with chlorsulfuron 24 hours after excision, the percentage of mitotic figures was reduced to near 0 by 8 hours. In roots treated with chlorsulfuron plus isoleucine and valine, no reduction in mitotic figures occurred. The complete reversal of chlorsulfuron-inhibited mitotic entry by isoleucine and valine implicates these amino acids, in some manner, with the control of cell cycles progression.

LD50 Rat (male) oral 5545 mg/kg|LD50 Rat (female) oral 6293 mg/kg|LD50 Rabbit dermal 3400 mg/kg|LD50 Rat ip 1450 mg/kg|LC50 Rat inhaltion >5900 mg/cu m/4 hr

/BIRDS and MAMMALS/ Chlorsulfuron is practically non-toxic to birds and mammals on an acute exposure basis and is also practically nontoxic to birds on a subacute dietary exposure basis. Following chronic exposure, bobwhite quail exhibited significant reductions in female body weight, 14-day old survivors/normal hatchlings, viable embryos/eggs set, and 14-day hatchling survival/eggs set. Chlorsulfuron is also practically nontoxic to honeybees on an acute contact basis.|/AQUATIC SPECIES/ Chlorsulfuron is practically nontoxic to both freshwater and estuarine/marine fish on an acute exposure basis and is slightly toxic to estuarine/marine invertebrates. Chronic exposure of rainbow trout (Oncorhynchus mykiss) to chlorsulfuron resulted in a No Observed Effect Concentration (NOEC) of 32 mg/L while a chronic study of waterfleas (Daphnia magna) resulted in a NOEC of 20 mg/L.|/AQUATIC SPECIES/ Aquatic plant toxicity ranged from practically nontoxic to very highly toxic. Duckweed (Lemna gibba) was the most sensitive vascular aquatic plant ... The most sensitive nonvascular aquatic plant is green algae ...|/AQUATIC SPECIES/ Research has been conducted on the effect of chlorsulfuron on non-target plants but little information is available on its effects on aquatic macrophytes. Potamogeton pectinatus (sago pondweed) is an ecologically important submerged aquatic macrophyte found in freshwater bodies. Many species of wildlife use this plant as a food source. The objective of this study was to measure the phytotoxic effects of chlorsulfuron on sago pondweed. P. pectinatus plants were exposed to chlorsulfuron at 0, 0.25, 0.50, 1.0, or 2.0 ppb, in an environmental growth chamber. Plants exposed to 0.25 ppb chlorsulfuron showed a reduction in length (76%), number of leaves (50%), and number of stems (50%), compared to control plants. A reduction (47%) was also observed in the length of stems produced by plants treated with > or = 0.50 ppb chlorsulfuron. Significant reductions in wet and dry weights, and increased mortality were observed on treatments with > or = 1.0 ppb chlorsulfuron.|For more Ecotoxicity Excerpts (Complete) data for Chlorsulfuron (10 total), please visit the HSDB record page.

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

TERRESTRIAL FATE: Based on a classification scheme(1), Koc values of 6.3-154(2-3) indicate that chlorsulfuron is expected to have very high to high mobility in soil(SRC). The pKa of chlorsulfuron is 3.4(4), indicating that this compound will exist almost entirely in the anion form in the environment and anions generally do not adsorb more strongly to soils containing organic carbon and clay than their neutral counterparts(5). Volatilization of the anion from moist soil is not expected because anions do not volatilize(SRC). Chlorsulfuron is not expected to volatilize from dry soil surfaces(SRC) based upon a vapor pressure of 2.25X10-11 mm Hg at 25 °C(4). The degradation half-life of chlorsulfuron incubated at 70% field capacity and 30 °C for 7 weeks was 8 and 6 days in samples from the 0-20 (pH 5.6 and 26.4% organic matter) and 20-40 cm (pH 5.2 and 35.1% organic matter) depths, respectively(6). Degradation of chlorsulfuron in 2 different soils at 25 °C and a moisture content 70% of field capacity followed 1st order kinetics, with rate constants of 0.015 and 0.025/day(7). Chlorsulfuron decomposition was faster in the soil with greater organic matter (3.0 vs 1.9%) and lower pH (6.0 vs 7.6)(7). N-(2-Chlorobenzenesulfonyl)carbamic acid was identified as a breakdown product(7). Chlorsulfuron applied to alkaline soils (pH 7.1-9.4) at 40 ug/kg and maintained at 70% of field capacity and 25 °C, degraded with half-lives of 19 to 42 days in surface soils(8). The rate of degradation decreased with increasing soil depth, as half-lives were nearly four times greater at 30-40 cm, as compared to the surface soils(8). The half-life of chlorsulfuron was 12-28 days in the field in soils with pH values of 4.9-6.5 with temperatures of 2.7-23.2 °C(9).|AQUATIC FATE: Based on a classification scheme(1), Koc values of 6.3-154(2-3) indicate that chlorsulfuron may adsorb to suspended solids and sediment(SRC). A pKa of 3.4(4) indicates chlorsulfuron will exist almost entirely in the anion form at pH values of 5 to 9 and, therefore, volatilization from water surfaces is not expected to be an important fate process(SRC). Chlorsulfuron will undergo hydrolysis with aqueous half-lives of 4 weeks at pH 5.7 and 8 weeks at pH 7.0 at 20 °C(5). According to a classification scheme(6), an estimated BCF of 3(SRC), from its log Kow of -1.34(7) and a regression-derived equation(8), suggests the potential for bioconcentration in aquatic organisms is low. Photolysis in sunlit surface waters may be an important fate process given an aqueous photolysis half-life of 1 month(9). Biodegradation of chlorsulfuron in water is expected to occur slowly given half-lives of 103 to 207 days at 40 °C in alkaline(pH 7.5 to 8.7) river water obtained from the Arno River, Italy(10).|ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), chlorsulfuron, which has a vapor pressure of 2.25X10-11 mm Hg at 25 °C(2), is expected to exist solely in the particulate phase in the ambient atmosphere. Particulate-phase chlorsulfuron may be removed from the air by wet and dry deposition(SRC). Chlorsulfuron is unlikely to undergo direct photolysis in the atmosphere(3).

The chemical hydrolysis of chlorsulfuron both in aqueous solution and in moist soil was faster at lower pH and higher temperature(1-2). The rate of hydrolysis in soil is more than 6 times faster at pH 5.7 than at a pH 7.5(1). The half-life in soil at 30 °C increased from 3 weeks at pH 5.9 to 4 weeks at pH 6.5(2). At 20 °C, hydrolysis half-lives for aqueous chlorsulfuron were 4 weeks at pH 5.7 and 8 weeks at pH 7.0(3). The half-life of chlorsulfuron in aqueous solution on irradiation with artificial sunlamp is 1 month(4). A dry film of chlorsulfuron on a glass plate underwent 15% decomposition in 1 month upon irradiation with artificial sunlight(4). Chlorsulfuron is unlikely to undergo direct photolysis in the atmosphere(5).

An estimated BCF of 3 was calculated in fish for chlorsulfuron(SRC), using a log Kow of -1.34(1) and a regression-derived equation(2). According to a classification scheme(3), this BCF suggests the potential for bioconcentration in aquatic organisms is low. The BCF of chlorsulfuron in unicellular green algae was measured as 8, 36 and 53 at pH 6, 5.3 and 5.0, respectively(4).

154.88 L/kg|Experimental Koc values of 6.3 to 154 have been reported in many different soil types(1-8). Decreases in the amount of organic carbon, an increase in soil pH and an increase in soil temperature have been observed to result in an increase in the mobility of chlorsulfuron(1-6). At a pH of approximately 4, chlorsulfuron was moderately adsorbed to soil, but was weakly adsorbed and very mobile at higher pH(3). According to a classification scheme(9), these Koc values suggest that chlorsulfuron is expected to have very high to high mobility in soil.|Experimental soil adsorption coefficient's of chlorsulfuron were reported in soils at different temperatures as follows(1):[Table#6362]|The soil distribution coefficients (Kd and Koc) of chlorsulfuron in three tilled surface soils collected in Spain were as follows(1):[Table#6363]|Leaching of the herbicides chlorsulfuron and metsulfuron methyl was studied using field lysimeters containing either undisturbed soil monoliths or packed soil. Three soil types were represented, two sandy soils and one clay soil. Each herbicide was applied at two rates, 4 and 8 g ai/ha, representing normal and double doses of the compound for spring cereals. All lysimeters received supplementary watering in addition to natural rainfall. With the exception of a single sample that had a chlorsulfuron concentration (14 ng/L) just above the detection limit, neither compound was detectable in leachate from lysimeters receiving the normal dose of the herbicides. For both herbicides at double dose, levels above the minimum detectable were found in selected lysimeters, reaching 43 and 21 ng/L drainage water for chlorsulfuron and metsulfuron methyl, respectively. Converted to fluxes over the 7 mo period, considerably less than 1% of the applied chlorsulfuron and metsulfuron methyl appeared in leachate.|For more Soil Adsorption/Mobility (Complete) data for Chlorsulfuron (7 total), please visit the HSDB record page.

A pKa of 3.4(1) indicates chlorsulfuron will exist almost entirely in the anion form at pH values of 5 to 9 and, therefore, volatilization from water surfaces is not expected to be an important fate process(SRC). Chlorsulfuron is not expected to volatilize from dry soil surfaces(SRC) based upon a vapor pressure of 2.25X10-11 mm Hg(1).

SURFACE WATER: Chlorsulfuron was detected at 0.013 ug/L in one of 129 water samples collected in 1998 from Midwestern streams and rivers(1). Chlorsulfuron was detected at 0.05 ug/L in the Iowa River, but was not detected in the Tensas River, LA, Mississippi River, IA, Wabash River, IN, and two sites in the Illinois River(2). Chlorsulfuron was not detected (detection limit 4.6 ng/L) in 399 surface water samples collected from Ontario and Quebec, Canada from 2006 to 2008(3).|GROUND WATER: Chlorsulfuron was not detected in 25 samples of groundwater collected in various parts of the Midwestern US in 1998(1). Chlorsulfuron was detected at 25-48 ng/L in groundwater of the Abruzzi Region of Central Italy(2).

Chlorsulfuron was not detected (detection limit 0.6 ug/kg) in 100 raw milk, 30 full-fat milk, 20 half-skimmed milk and 20 skimmed milk samples(1). Raw milk was provided by a local farm and all other milk samples were obtained from local supermarkets in Shenyang, China(1).

Occupational exposure to chlorsulfuron may occur through inhalation of dust or mists and dermal contact with this compound at workplaces where chlorsulfuron is produced or used. Monitoring data indicate that the general population is not likely to be exposed to chlorsulfuron. (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.)

Absorbed by foliage and roots of both resistant and susceptible species, with acropetal and basipetal translocation.

The sulfonylurea herbicide chlorsulfuron blocks the biosynthesis of the amino acids valine and isoleucine in plants. Addition of these two amino acids to excised pea root (Pisum sativum L. var Alaska) cultures incubated in the presence of chlorsulfuron completely alleviates herbicide-induced growth inhibition. The site of action of chlorsulfuron is the enzyme acetolactate synthase which catalyzes the first step in the biosynthesis of valine and isoleucine. This enzyme is extremely sensitive to inhibition by chlorsulfuron having I(50) values ranging from 18 to 36 nanomolar. In addition, acetolactate synthase from a wide variety of tolerant and sensitive plants species is highly sensitive to inhibition by chlorsulfuron.|Chlorsulfuron, an inhibitor of acetolactate synthase markedly inhibited the growth of Lemna minor at concentrations of 10(-8) molar and above, but had no inhibitory effects on growth at 10(-9) molar. At growth inhibitory concentrations, chlorsulfuron caused a pronounced increase in total free amino acid levels within 24 hours. Valine, leucine, and isoleucine, however, became smaller percentages of the total free amino acid pool as the concentration of chlorsulfuron was increased. At concentrations of chlorsulfuron of 10(-8) molar and above, a new amino acid was accumulated in the free pool. This amino acid was identified as alpha-amino-n-butyrate by chemical ionization and electron impact gas chromatography-mass spectrometry. The amount of alpha-amino-n-butyrate increased from undetectable levels in untreated plants, to as high as 840 nanomoles per gram fresh weight (2.44% of the total free pool) in plants treated with 10(-4) molar chlorsulfuron for 24 hours. The accumulation of this amino acid was completely inhibited by methionine sulfoximine. Chlorsulfuron did not inhibit the methionine sulfoximine induced accumulations of valine, leucine, and isoleucine, supporting the idea that the accumulation of the branched-chain amino acids in methionine sulfoximine treated plants is the result of protein turnover rather than enhanced synthesis. Protein turnover may be primarily responsible for the failure to achieve complete depletion of valine, leucine, and isoleucine even at concentrations of chlorsulfuron some 10(4) times greater than that required to inhibit growth. Tracer studies with (15)N demonstrate that chlorsulfuron inhibits the incorporation of (15)N into valine, leucine, and isoleucine. The alpha-amino-n-butyrate accumulated in the presence of chlorsulfuron and [(15)N]H(4) (+) was heavily labeled with (15)N at early time points and appeared to be derived by transamination from a rapidly labeled amino acid such as glutamate or alanine. We propose that chlorsulfuron inhibition of acetolactate synthase may lead to accumulation of 2-oxobutyrate in the isoleucine branch of the pathway, and transamination of 2-oxobutyrate to alpha-amino-n-butyrate by a constitutive transaminase utilizing either glutamate or alanine as alpha-amino-N donors.|The sulfonylurea herbicide chlorsulfuron and the imidazolinone herbicide imazaquin were shown to be noncompetitive and uncompetitive inhibitors, respectively, of purified acetolactate synthase from barley (Hordeum vulgare L.) with respect to pyruvate. From double-reciprocal plots of the time-dependent biphasic inhibition by chlorsulfuron, an initial apparent inhibition constant of 68 nanomolar was calculated (a 0 to 4 minute assay was used for the initial inhibition), and a final steady-state dissociation constant of 3 nanomolar was estimated. The corresponding constants for imazaquin were 10 and 0.55 micromolar. Specific binding of [(14)C]chlorsulfuron and [(14)C]imazaquin to purified acetolactate synthase from barley and partially purified enzyme from corn (Zea mays L.) could be demonstrated by gel filtration and equilibrium dialysis. Evidence is presented that the binding of the inhibitors to the enzyme follows the previously described mechanism of slow reversibility once excess inhibitor has been removed. However, after formation of the slowly reversible complex and subsequent dissociation, both chlorsulfuron and imazaquin seem to permanently inactivate acetolactate synthase. These results add a new feature to the mode of action of these herbicides with respect to their high herbicidal potency.|The DNA sequence of a 196 base pair region of the acetolactate synthase genes of three weed species, kochia, prickly lettuce, and Russian thistle, was determined. This region encompasses the coding sequence for Domain A, a region of the amino acid sequence previously demonstrated to play a pivotal role in conferring resistance to herbicides that inhibit acetolactate synthase. The Domain A DNA sequence from a chlorsulfuron resistant prickly lettuce biotype differed from that of a chlorsulfuron susceptible biotype by a single point mutation, which substituted a histidine for a proline. The Domain A DNA sequence from a chlorsulfuron resistant kochia biotype also differed from that of an chlorsulfuron susceptible biotype by a single point mutation in the same proline codon. This point mutation, however, conferred substitution of threonine for proline. Two different acetolactate synthase homologous sequences were isolated from an chlorsulfuron resistant biotype of Russian thistle. Neither sequence encoded amino acid substitutions in Domain A that differed from the consensus chlorsulfuron susceptible sequence. Most collections showed excellent correspondence between the chlorsulfuron susceptibility and restriction digest pattern and the phenotypic response to chlorsulfuron application. However, one entirely chlorsulfuron resistant collection had the chlorsulfuron susceptibility and restriction digest pattern of the chlorsulfuron susceptible biotype, suggesting that resistance was not due to mutation in the proline codon.|For more Mechanism of Action (Complete) data for Chlorsulfuron (7 total), please visit the HSDB record page.

Excerpt from ERG Guide 171 [Substances (Low to Moderate Hazard)]: Inhalation of material may be harmful. Contact may cause burns to skin and eyes. Inhalation of Asbestos dust may have a damaging effect on the lungs. Fire may produce irritating, corrosive and/or toxic gases. Some liquids produce vapors that may cause dizziness or suffocation. Runoff from fire control may cause pollution. (ERG, 2016)

Excerpt from ERG Guide 171 [Substances (Low to Moderate Hazard)]: Ensure that medical personnel are aware of the material(s) involved and take precautions to protect themselves. Move victim to fresh air. Call 911 or emergency medical service. Give artificial respiration if victim is not breathing. Administer oxygen if breathing is difficult. Remove and isolate contaminated clothing and shoes. In case of contact with substance, immediately flush skin or eyes with running water for at least 20 minutes. (ERG, 2016)

/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/|/SRP:/ Basic treatment: Establish a patent airway (oropharyngeal or nasopharyngeal airway, if needed). Suction if necessary. Watch for signs of respiratory insufficiency and assist ventilations if needed. Administer oxygen by nonrebreather mask at 10 to 15 L/min. Monitor for pulmonary edema and treat if necessary ... . Monitor for shock and treat if necessary ... . Anticipate seizures and treat if necessary ... . For eye contamination, flush eyes immediately with water. Irrigate each eye continuously with 0.9% saline (NS) during transport ... . Do not use emetics. For ingestion, rinse mouth and administer 5 mL/kg up to 200 mL of water for dilution if the patient can swallow, has a strong gag reflex, and does not drool ... . Cover skin burns with dry sterile dressings after decontamination ... . /Poisons A and B/|/SRP:/ Advanced treatment: Consider orotracheal or nasotracheal intubation for airway control in the patient who is unconscious, has severe pulmonary edema, or is in severe respiratory distress. Positive-pressure ventilation techniques with a bag valve mask device may be beneficial. Consider drug therapy for pulmonary edema ... . Consider administering a beta agonist such as albuterol for severe bronchospasm ... . Monitor cardiac rhythm and treat arrhythmias as necessary ... . Start IV administration of D5W TKO /SRP: "To keep open", minimal flow rate/. Use 0.9% saline (NS) or lactated Ringer's (LR) if signs of hypovolemia are present. For hypotension with signs of hypovolemia, administer fluid cautiously. Watch for signs of fluid overload ... . Treat seizures with diazepam or lorazepam ... . Use proparacaine hydrochloride to assist eye irrigation ... . /Poisons A and B/

chlorsulfuron

NUP 08136 (Nufarm Americas, Inc): Active ingredient: chlorsulfuron 15% and metsulfuron 48%.|Nufarm Chlorsulf SPC 75 WDG Herbicide (Nufarm Americas, Inc): Active ingredient: chlorsulfuron 75%.|ETI 123 01 H-D2 (Nufarm Americas, Inc): Active ingredient: chlorsulfuron 75%.|ETI 122 01 H-D (Nufarm Americas, Inc): Active ingredient: chlorsulfuron 62.5% and metsulfuron 12.5%.|For more Formulations/Preparations (Complete) data for Chlorsulfuron (33 total), please visit the HSDB record page.

The WHO Recommended Classification of Pesticides by Hazard identifies Chlorsulfuron (technical grade) as unlikely to present an acute hazard in normal use; Main Use: herbicide.|Application methods: Preemergence or early postemergence treatments show the most activity on annual grass weeds and broadleaf weeds. Later postemergence treatments are effective on most broadleaf weeds but less effective on grasses. Treatments may be made with aerial or ground equipment. Rates: 0.2-0.5 oz/acre preemergence or postemergence on wheat and only postemergence on barley, oats, rye and flax. 0.5-1.5 oz/acre for fallow weed control. Usual carrier: water 1.5-40 gallons/acre plus a surfactant @ 0.1% by volume for control of emerged weeds.

Matrix solid-phase dispersion combined with dispersive liquid-liquid microextraction has been developed as a new sample pretreatment method for the determination of four sulfonylurea herbicides (chlorsulfuron, bensulfuron-methyl, chlorimuron-ethyl, and pyrazosulfuron) in tea by high-performance liquid chromatography with diode array detection. The extraction and cleanup by matrix solid-phase dispersion was carried out by using CN-silica as dispersant and carbon nanotubes as cleanup sorbent eluted with acidified dichloromethane. The eluent of matrix solid-phase dispersion was evaporated and redissolved in 0.5 mL methanol, and used as the dispersive solvent of the following dispersive liquid-liquid microextraction procedure for further purification and enrichment of the target analytes before high-performance liquid chromatography analysis. Under the optimum conditions, the method yielded a linear calibration curve in the concentration range from 5.0 to 10 000 ng/g for target analytes with a correlation coefficients (r(2)) ranging from 0.9959 to 0.9998. The limits of detection for the analytes were in the range of 1.31-2.81 ng/g. Recoveries of the four sulfonylurea herbicides at two fortification levels were between 72.8 and 110.6% with relative standard deviations lower than 6.95%. The method was successfully applied to the analysis of four sulfonylurea herbicides in several tea samples.|This study proposes a fast, simple and sensitive liquid chromatography diode array detector (LC/UV-DAD)-based method for the simultaneous determination of eight sulfonylurea herbicides (bensulfuron methyl, chlorsulfuron, metsulfuron methyl, primisulfuron methyl, rimsulfuron, thifensulfuron methyl, triasulfuron and tribenuron methyl) in bovine whole milk at concentrations lower than the default limit of 0.01 mg/kg allowed by current legislation (Regulation EC/396/2005 and following Annexes). An effective one-step solid phase extraction (SPE) and clean up procedure was defined with use of Chem Elut cartridges, providing good recoveries for all the analytes tested and with no matrix effects affecting method accuracy. Separation of herbicides was obtained on a C(18) column by acetonitrile- water gradient elution. Method validation has been performed according to European Commission Decision 2002/657/EC criteria, in terms of linearity, recovery, precision, specificity, decision limit (CC(alpha)) and detection capability (CC(beta)). Typical recoveries ranged between 78.4% and 99.7%, at the maximum residue limits (MRLs) levels established by Regulation EC/396/2005, with relative standard deviations (RSD) no larger than 10%.|Sulfonylureas (SUs) are one of the most widely used herbicides to control weeds in crops. Herein, capillary electrophoresis (CE) was used to determine four sulfonylureas in natural waters, namely chlorsulfuron (CS), iodosulfuron methyl (IM), metsulfuron methyl (MSM) and mesosulfuron methyl (MSS). First of all, a bare silica capillary was chosen with 10 mM of 1-butyl-3-methylimidazolium tetrafluoroborate (bminBF4) as electrophoretic buffer (pH 9.6) containing 2 mg/L of surfactant-coated single-wall carbon nanotubes (SC-SWCNTs). A dramatic deviation in migration times was observed. Therefore, a poly(diallyldimethylammonium) chloride (PDADMAC) statically coated cationic capillary was used to improve repeatability and to alter the selectivity of the separation. The electroosmotic flow (EOF) measurement revealed that the SC-SWCNTs were strongly adsorbed at the surface of the PDADMAC coating even in the absence of the surfactant-coated nanotubes in the electrolyte buffer. Consequently, a stable strong cathodic EOF and excellent repeatabilities were obtained with relative standard deviations (RSDs) on migration times and on corrected peak areas below 0.9 and 1.5%, respectively. The separation of the SUs was conducted in only 6 min. No regeneration of the coating between analyses was necessary, and high peak efficiencies up to 173,000 theoretical plates were obtained. The bi-layer coating was subsequently used to analyze sulfonylureas in tap water, in several mineral waters as well as in underground waters spiked with SUs and directly injected into the CE capillary.|A method based on liquid extraction followed by sample enrichment on reversed-phase solid-phase extraction was developed for the extraction of five degradation products of four sulfonylurea herbicides (chlorsulfuron, metsulfuron-methyl, thifensulfuron-methyl and tribenuron-methyl) from soil. The compounds have been quantified by LC-UV and identified by tandem LC-MS with electrospray ionization or atmospheric pressure chemical ionization. The limits of detection for the five compounds were between 10 and 50 ug/kg. The method has been applied to the extraction of soil samples after microbial degradation of sulfonylurea herbicides.|For more Analytic Laboratory Methods (Complete) data for Chlorsulfuron (23 total), please visit the HSDB record page.

A new simple methodology is proposed for chlorsufuron (CS) traces quantification based upon enhancement of rhodamine B (RhB) fluorescent signal. Experimental variables that influence fluorimetric sensitivity have been studied and optimized. The zeroth order regression calibration was linear from 0.866 to 35.800 ug/L CS, with a correlation coefficient of 0.99. At optimal experimental conditions, a limit of detection of 0.259 ug/L and a limit of quantification of 0.866 ug/L were obtained. The method showed good sensitivity and adequate selectivity and was applied to the determination of trace amounts of CS in plasma, serum and water samples with satisfactory results analyzed by ANOVA test. The proposed methodology represents an alternative to traditional chromatographic techniques for CS monitoring in complex samples, using an accessible instrument in control laboratories.

Agrochemicals -> Herbicides

Chlorsulfuron has known environmental transformation products that include 2-amino-4-methoxy-6-methyl-1,3,5-triazine.