Chloroxuron

290.74

290.74

217-843-7

QER23C88ME

3077|2767

DTXSID7040287

WHITE CRYSTALS|COLORLESS POWDER|Colorless crystals

2924299034

41.6

3.20

solid

1.34 g/cm³ @ Temp: 20 °C

151 °C

459.3±41.0 °C(Predicted)

>100 °C

1.5200 (estimate)

Organic solubility at 20 deg C (ppm): Dichloromethane - 1.1X10+5; Acetone - 4.4X10+4; Methanol - 3.5X10+4; Toluene - 4.0X10+3. Water - 2.5 ppm at 22 deg C

0-6°C

Vapor pressure = 3.9X10-9 mm Hg at 25 deg C

Oral-Rat LD50: 3700 mg/kg; Oral-Mouse LD50: 1000 mg/kg

Combustion produces toxic nitrogen oxides and chloride gases

ODORLESS

172.24 Ų [M+H]+ [CCS Type: TW]

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

Amides and Imides

Fire may produce irritating or poisonous gases. When heated to decomposition it emits very toxic fumes of chlorides and nitrogen oxides. [EPA, 1998].

Noncorrosive

UN30779/PG3

2

50/53

60-61

YS6125000

N

The warehouse is ventilated, low temperature and dry; stored and transported separately from food materials

Stable. Incompatible with strong oxidizing agents.

P273

H332-H400

Incinerate in a unit with effluent gas scrubbing. Recommendable method: Incineration.|SRP: At the time of review, criteria for land treatment or burial (sanitary landfill) disposal practices are subject to significant revision. Prior to implementing land disposal of waste residue (including waste sludge), consult with environmental regulatory agencies for guidance on acceptable disposal practices.

VOSS G ET AL; FLUOMETURON, METOBROMURON, CHLORBROMURON, AND CHLOROXURON; ANAL METHODS PESTIC PLANT GROWTH REGUL 7: 569-94 (1973). REVIEW OF CHLOROXURON & SEVERAL OTHER HERBICIDES, WITH EMPHASIS ON ANALYTICAL PROCEDURES.

(Non-Specific -- Pesticide, Solid, n.o.s.) Fire may produce irritating or poisonous gases. When heated to decomposition it emits very toxic fumes of chlorides and nitrogen oxides. (EPA, 1998)

|Warning|H332 (100%): Harmful if inhaled [Warning Acute toxicity, inhalation]|P261, P271, P273, P304+P312, P304+P340, P312, P391, and P501|Aggregated GHS information provided by 41 companies from 2 notifications to the ECHA C&L Inventory. Each notification may be associated with multiple companies.

(Non-Specific -- Pesticide, Solid, n.o.s.) Avoid breathing vapors or dust. Wear self-contained (positive pressure if available) breathing apparatus and full protective clothing. (Non-Specific -- Pesticide, Solid, n.o.s.) For small fires, use dry chemical, carbon dioxide, water spray, or foam. For large fires, use water spray, fog, or foam. (EPA, 1998)

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)

(Non-Specific -- Pesticide, Solid, n.o.s.) Do not touch spilled material; stop leak if you can do it without risk. Use water spray to reduce vapors. Small spills: take up with sand or other noncombustible absorbent material and place into containers for later disposal. Small dry spills: with clean shovel place material into clean, dry container and cover; move containers from spill area. Large spills: dike far ahead of spill for later disposal. Use caution with this material. (EPA, 1998)

For emergency situations, wear a positive pressure, pressure-demand, full facepiece self-contained breathing apparatus (SCBA) or pressure- demand supplied air respirator with escape SCBA and a fully-encapsulating, chemical resistant suit. (EPA, 1998)|The use of personal protective equipment such as glasses, synthetic gloves and face masks is important. /Herbicides/

NONFLAMMABLE.

Only clean clothing and underwear should be worn and clothing should be changed daily for freshly washed clothes. Contaminated equipment should not be taken home. Adequate sanitary facilities and washing water should be provided for workers to wash before meals. Smoking and the consumption of alcoholic drinks before or during the handling of herbicides should be forbidden. Contaminated clothing should be removed immediately and a hot bath taken if possible. /Herbicides/|Fully enclosed processes, remote control and exhaust ventilation should be used. /Herbicides/|Herbicides should not be removed from their original containers. Injurious concentrates should be used in small containers that are easy to handle and to destroy. /Herbicides/

moderately toxic

LD50 Rat oral 3000 mg/kg /Technical chloroxuron/|LC50 Rat inhalation >1.35 mg/l air/6 hr|LD50 Rat oral 3700 mg/kg, male|LD50 Rabbit dermal >10,000 mg/kg

Chloroxuron is of anthropogenic origin, and it is not known to be produced by natural sources. (SRC)

Chloroxuron's former use as an herbicide(1) will have resulted in its release to the environment(SRC).

Terrestrial fate: Duration of residual activity in soil is about 4 months.|TERRESTRIAL FATE: The recommended Koc value for chloroxuron in soil is 2820, with values ranging from 1323 to 6220(1). A recommended regression-derived equation(2), indicates that chloroxuron is expected to have slight mobility in soil(SRC). Volatilization of chloroxuron from moist soil surfaces is not expected(SRC) given an estimated Henry's Law constant of 4.03X10-10 atm-cu m/mole(SRC), using an experimental vapor pressure and water solubility(3,4). Chloroxuron is not expected to volatilize from dry soil surfaces based on an experimental vapor pressure of 3.9X10-9 mm Hg(3,SRC). The field dissipation half-life of chloroxuron has a recommended value of 45 days; however, values range from 30 to 60 days(1). The half-life of chloroxuron in silt loam soil under aerobic conditions is recommended as 110 days(1). Bacterial suspensions derived from humus soil were demonstrated to metabolize chloroxuron to N-(4-chlorophenoxy)-phenyl-N-methylurea, N-(4-chlorophenoxy)-phenylurea, and (4-chlorophenoxy)-aniline(5).|AQUATIC FATE: Based on a recommended classification scheme(1), a recommended Koc value of 2820(2,SRC) indicates that chloroxuron is expected to adsorb to suspended solids and sediment(s) in water(SRC). Chloroxuron is not expected to volatilize from water surfaces(3,SRC) based on an estimated Henry's Law constant of 4.03X10-10 atm-cu m/mole(SRC), calculated from experimental vapor pressure and water solubility(4,5). Biodegradation of chloroxuron in soil would suggest that biodegradation of chloroxuron in water systems may be important(SRC). According to a classification scheme(6), an estimated BCF value of 295(3,SRC) from an experimental water solubility(5), suggests that bioconcentration in aquatic organisms is high(SRC).|ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), chloroxuron, which has an experimental vapor pressure of 3.9X10-9 mm Hg at 25 °C(2,SRC), is expected to exist solely as a particulate in the ambient atmosphere. Particulate-phase chloroxuron may be physically removed from the air by wet and dry deposition(SRC).

NEARLY ALL HERBICIDES HAVE BEEN REPORTED TO UNDERGO INACTIVATION IN LIGHT IN VITRO. AMONG THEM ... CHLOROXURON ... .|In soil, splitting off the methyl groups, degradation of the urea derivative with the formation of carbon dioxide, ammonia, & 4-chloro-4'-aminodiphenyl ester.|Under model conditions, irradiation with an ultra-violet light source of 300 watts, photodestruction of chloroxuron was found to be rapid: 90 percent loss within 13 hours. Mono- (2.2 percent) and di-demethylated (4.2 percent) products were identified in the reaction mixture and 64 percent of the original radioactive label was evolved as carbon dioxide(1). The half-life for the photolysis of chloroxuron in natural light or artificial light source > 250 nm is < 0.04 days(2). The hydrolysis half-life of chloroxuron ranges from 1208 to 4583 days, temperature and pH not stated(2).

An estimated BCF value of 295 was calculated for chloroxuron(SRC), using an experimental water solubility of 3.7 mg/l(1,SRC) and a recommended regression-derived equation(2). According to a classification scheme(3), this BCF value suggests that bioconcentration in aquatic organisms is high, but not very high(SRC).

3.55e+03 L/kg|CHLOROXURON IS QUITE STRONGLY ADSORBED ON SOIL PARTICLES & THIS SEEMS TO BE AN IMPORTANT FACTOR IN CONTROLLING ITS AVAILABILITY IN SOIL SOLN & DETERMINING BOTH THE INITIAL TOXICITY & THE RESIDUAL ACTIVITY IN SOME TYPES OF SOILS. THE FOLLOWING CONCN OF CHLOROXURON ADSORBED WERE IN EQUIL WITH 1 PPM SOIL SOLN: 14 UG/G (SANDY LOAM), 40 UG/G (CLAY LOAM), & 110 UG/G (HUMUS SOIL). WITH SOIL COLUMNS (SANDY, CLAY, & HUMUS SOILS) & SIMULATED RAIN (200 MM IN 45 HR), THE BULK OF CHLOROXURON WAS NOT REMOVED FROM THE TOP 1 CM LAYER OF ALL THREE SOILS. LEACHING DOES NOT APPEAR TO BE A FACTOR IN REMOVING CHLOROXURON FROM THE SURFACE OF SOIL.|The recommended Koc value for chloroxuron in soil is 2820, with values ranging from 1323 to 6220(1). According to a recommended classification scheme(2), this estimated Koc value suggests that chloroxuron is expected to have slight mobility in soil(SRC). The mobility of chloroxuron in Hagerstown silt clay loam was determined using soil thin layer chromatography. Results showed an Rf value of 0.09, corresponding to a classification of 1, immobile(3). Adsorption of chloroxuron on montmorillonite ranged from 50 to 400 umol/g(4).

The Henry's Law constant for chloroxuron is estimated as 4.03X10-10 atm-cu m/mole(SRC) from its experimental values for vapor pressure, 3.9X10-9 mm Hg(1), and water solubility, 3.7 mg/l(2). This value indicates that chloroxuron will be essentially nonvolatile from water surfaces(3,SRC). Chloroxuron's Henry's Law constant(1,2,SRC) indicates that volatilization from moist soil surfaces is not expected(SRC). Chloroxuron is not expected to volatilize from dry soil surfaces based on a measured vapor pressure of 3.9X10-9 mm Hg(1).

SURFACE WATER: Analysis of a British lowland river, a West German lowland river, and British drinking waters was conducted. Chloroxuron was identified in river water, concentrations unknown(1).|GROUNDWATER: Groundwater sampling for pesticides in the United States was conducted by the EPA from 1971 to 1991. Results showed that out of 21 wells sampled in California from 1988 to 1989, no concentration of chloroxuron was detected(1).

Occupational exposure to chloroxuron may be through inhalation of dusts and dermal contact with this compound at workplaces where chloroxuron is produced or used. (SRC)

IT IS ABSORBED BY ROOTS AND LEAVES.|PLANTS GROWN IN NUTRIENT SOLN ACCUMULATE MORE (14)C-LABELED CHLOROXURON IN THE ROOTS THAN IN THE STEMS OR LEAVES. THE MAIN SITE OF ENTRY OF CHLOROXURON IS THE APICAL HALF OF ROOTS.|Following foliar application, chloroxuron is not translocated appreciably by the assimilate stream. It is strongly absorbed by root tissues once it has been carried into the root zone by water movement.

Following oral admin, metabolism proceeds by oxidative demethylation & 90-95% elimination occurs within 24 hr.|ZEA MAYS, VICIA FABA, PHASEOLUS VULGARIS, GALINSOGA PARVIFLORA, POLYGONUM CONVOLVULUS WERE EXPOSED TO LABELED N'-(4-CHLOROPHENOXY)-PHENYL-N,N-DIMETHYLUREA. ... N'-(4-CHLOROPHENOXY)-PHENYL-N-METHYLUREA AND N'-(4-CHLOROPHENOXY)-PHENYLUREA WERE IDENTIFIED BY INFRA RED.|OXIDATIVE REACTION TAKING PLACE WITH HERBICIDES IN PLANTS ARE, FOR EXAMPLE, DEMETHYLATION REACTIONS THAT HAVE BEEN REPORTED FOR CHLOROXURON ... THESE ... REACTIONS PROCEED PROBABLY VIA CORRESPONDING METHYLOL COMPOUNDS WHICH ... WILL DECOMP WITH FORMATION OF A METHYLAMINE & FORMALDEHYDE.|CHLOROXURON IS ENZYMATICALLY DEGRADED BY PLANTS TO THE MONOMETHYLATED & DEMETHYLATED DERIVATIVES, FOLLOWED BY DECARBOXYLATION OF THE PHENOXYPHENYLUREA TO FORM (4-CHLOROPHENOXY)ANILINE. THE ANILINE DERIVATIVE MAY BE FORMED BY DIRECT HYDROLYSIS OF CHLOROXURON. THERE IS NO EVIDENCE THAT CONJUGATION OF CHLOROXURON DEGRADATION PRODUCTS OCCUR.

Their herbicidal activity depends on inhibition of photosynthesis by blocking of electron transport in Photosystem II. /Ureas/

This is highly toxic by ingestion. Under certain conditions, chloroxuron will form carcinogenic dimethylnitrosamine. (EPA, 1998)

Signs and Symptoms of Chloroxuron Exposure: Acute exposure to chloroxuron may produce the following signs and symptoms: dilated pupils, visual disturbances, methemoglobinemia, cyanosis, chest pain, irregular heartbeat, abdominal pain, nausea, vomiting, diarrhea, anorexia, dehydration, urinary retention, and urinary tract irritation. Muscular weakness, aching, tremors, mental confusion, and central nervous system depression may also be noted. Contact with chloroxuron dust may produce irritation of the eye and mucous membranes of the respiratory system. Emergency Life-Support Procedures: Acute exposure to chloroxuron may require decontamination and life support for the victims. Emergency personnel should wear protective clothing appropriate to the type and degree of contamination. Air-purifying or supplied-air respiratory equipment should also be worn, as necessary. Rescue vehicles should carry supplies such as plastic sheeting and disposable plastic bags to assist in preventing spread of contamination. Inhalation Exposure: 1. Move victims to fresh air. Emergency personnel should avoid self-exposure to chloroxuron. 2. Evaluate vital signs including pulse and respiratory rate, and note any trauma. If no pulse is detected, provide CPR. If not breathing, provide artificial respiration. If breathing is labored, administer 100% humidified oxygen or other respiratory support. 3. Obtain authorization and/or further instructions from the local hospital for administration of an antidote or performance of other invasive procedures. 4. Transport to a health care facility. Dermal/Eye Exposure: 1. Remove victims from exposure. Emergency personnel should avoid self-exposure to chloroxuron. 2. Evaluate vital signs including pulse and respiratory rate, and note any trauma. If no pulse is detected, provide CPR. If not breathing, provide artificial respiration. If breathing is labored, administer 100% humidified oxygen or other respiratory support. 3. Remove and isolate contaminated clothing as soon as possible. 4. If eye exposure has occurred, eyes must be flushed with lukewarm water for at least 15 minutes. 5. Wash exposed skin areas thoroughly with soap and water. 6. Obtain authorization and/or further instructions from the local hospital for administration of an antidote or performance of other invasive procedures. 7. Transport to a health care facility. Ingestion Exposure: 1. Evaluate vital signs including pulse and respiratory rate, and note any trauma. If no pulse is detected, provide CPR. If not breathing, provide artificial respiration. If breathing is labored, administer 100% humidified oxygen or other respiratory support. 2. Obtain authorization and/or further instructions from the local hospital for administration of an antidote or performance of other invasive procedures. 3. Vomiting may be induced with syrup of Ipecac. If elapsed time since ingestion of chloroxuron is unknown or suspected to be greater than 30 minutes, do not induce vomiting and proceed to Step 4. Ipecac should not be administered to children under 6 months of age. Warning: Syrup of Ipecac should be administered only if victims are alert, have an active gag-reflex, and show no signs of impending seizure or coma. If ANY uncertainty exists, proceed to Step 4. The following dosages of Ipecac are recommended: children up to 1 year old, 10 mL (1/3 oz); children 1 to 12 years old, 15 mL (1/2 oz); adults, 30 mL (1 oz). Ambulate (walk) the victims and give large quantities of water. If vomiting has not occurred after 15 minutes, Ipecac may be readministered. Continue to ambulate and give water to the victims. If vomiting has not occurred within 15 minutes after second administration of Ipecac, administer activated charcoal. 4. Activated charcoal may be administered if victims are conscious and alert. Use 15 to 30 g (1/2 to 1 oz) for children, 50 to 100 g (1-3/4 to 3-1/2 oz) for adults, with 125 to 250 mL (1/2 to 1 cup) of water. 5. Promote excretion by administering a saline cathartic or sorbitol to conscious and alert victims. Children require 15 to 30 g (1/2 to 1 oz) of cathartic; 50 to 100 g (1-3/4 to 3-1/2 oz) is recommended for adults. 6. Transport to a health care facility. (EPA, 1998)

1. SKIN CONTAMINATION SHOULD BE REMOVED PROMPTLY BY WASHING WITH SOAP AND WATER. CONTAMINATION OF THE EYES SHOULD BE TREATED IMMEDIATELY BY PROLONGED FLUSHING OF THE EYES WITH COPIOUS AMOUNTS OF CLEAN WATER. IF DERMAL OR OCULAR IRRITATION PERSISTS, MEDICAL ATTENTION SHOULD BE OBTAINED WITHOUT DELAY. /OTHER HERBICIDES/|2. INGESTIONS OF THESE HERBICIDES ARE LIKELY TO BE FOLLOWED BY VOMITING AND DIARRHEA DUE TO THE IRRITANT PROPERTIES OF MOST OF THE TOXICANTS. ... A. IF LARGE AMOUNTS OF HERBICIDE HAVE BEEN INGESTED, AND IF THE PATIENT IS FULLY ALERT, INDUCE EMESIS WITH SYRUP OF IPECAC, FOLLOWED BY SEVERAL GLASSES OF WATER. DOSAGE FOR ADULTS AND CHILDREN OVER 12 YEARS: 30 ML; DOSAGE FOR CHILDREN UNDER 12 YEARS 15 ML. WHEN VOMITING HAS STOPPED, GIVE ACTIVATED CHARCOAL. ADD SORBITOL TO THE CHARCOAL SLURRY UNLESS DIARRHEA HAS ALREADY COMMENCED. IF, FOR SOME REASON, THE PATIENT IS NOT FULLY ALERT, PUT IN PLACE A CUFFED ENDOTRACHEAL TUBE TO PROTECT THE AIRWAY, THEN ASPIRATE AND LAVAGE THE STOMACH WITH A SLURRY OF ACTIVATED CHARCOAL. LEAVE A QUANTITY OF CHARCOAL, WITH SORBITOL, IN THE STOMACH BEFORE WITHDRAWING THE STOMACH TUBE. REPEATED ADMINISTRATION OF CHARCOAL AT HALF OR MORE THE INITIAL DOSAGE EVERY 2-4 HOURS MAY BE BENEFICIAL. /OTHER HERBICIDES/|2. B. IF THE AMOUNT OF INGESTED HERBICIDES WAS SMALL, IF EFFECTIVE EMESIS HAS ALREADY OCCURRED, OR IF TREATMENT IS DELAYED, ADMINISTER THE ACTIVATED CHARCOAL AND SORBITOL BY MOUTH. C. IF SERIOUS DEHYDRATION AND ELECTROLYTE DEPLETION HAVE OCCURRED AS A RESULT OF VOMITING AND DIARRHEA, MONITOR BLOOD ELECTROLYTES AND 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. FLUIDS SERVE TO SUPPORT EXCRETION OF THE TOXICANTS. D. SUPPORTIVE MEASURES ARE ORDINARILY SUFFICIENT FOR SUCCESSFUL MANAGEMENT OF EXCESSIVE EXPOSURES TO THESE HERBICIDES. /OTHER HERBICIDES/

Symptoms of intoxication: Depression, peripheral vasoconstriction, locomotion, hyperpnea, gasping, coma, death.

chloroxuron

HERBICIDE, OF WHICH APPROXIMATELY 80% IS USED ON SOYBEANS, 10% ON DECIDUOUS FRUITS, AND 10% ON VEGETABLES (1975)|Use in US agriculture (1000 pounds AI/yr): 1982 - 18; 1989 - 62

Mixed formulations: (chloroxuron +) iron sulfate; dichlorophen + iron sulfate.|'Tenoran' WP, wettable powder, 500 g ai/kg.

COMPATIBLE WITH OTHER HERBICIDES.|APPLICATION METHODS: PREEMERGENCE BROADCAST OR BAND TREATMENTS TO THE SURFACE OF THE SOIL AT PLANTING; SOIL INCORPORATION OF CHLOROXURON DOES NOT IMPROVE PERFORMANCE. POSTEMERGENCE TO CROPS & POSTEMERGENCE TO WEEDS; FOR BEST RESULTS APPLY JUST AFTER WEED EMERGENCE BUT CERTAINLY BEFORE WEEDS ARE 2 INCHES HIGH. MAKE APPLICATION WITH CONVENTIONAL SPRAY EQUIPMENT. RATES: RANGE: 1-4 LB/ACRE; 1-1.5 LB/ACRE FOR SOYBEANS; 3-4 LB/ACRE FOR CARROTS & ONIONS. USUAL CARRIER: WATER AT 25 TO 40 GPA, CONSTANT AGITATION, SCREEN SIZE 50 MESH OR LARGER.|CHLOROXURON IS ABSORBED BY BOTH ROOTS AND LEAVES, RECOMMENDED FOR CONTROL OF WEEDS IN STRAWBERRIES AT 3.5-4.5 KG AI/HA, PRE-EMERGENCE OR AFTER TRANSPLANTING, OR IN SOYBEANS, ORNAMENTALS & CONIFERS @ SIMILAR RATES. AT THESE RATES IT DISSIPATES TO NON-PHYTOTOXIC CONCN WITHIN 2 MONTHS.|Discontinued by Ciba-Geigy Ltd.

CHLOROXURON WAS EXTRACTED FROM GRAIN, SOIL & AQUEOUS SAMPLES & DETERMINED BY HPLC. DETECTION LIMITS WERE 0.2 PPM FOR WHEAT & SOIL, 0.01 PPM FOR WATER.|PRODUCT ANALYSIS IS BY DETERMINATION OF THE DIMETHYLAMINE PRODUCED BY HYDROLYSIS. RESIDUES MAY BE DETERMINED BY HYDROLYSIS TO 4-(4-CHLOROPHENOXY) ANILINE, OF WHICH ARE MEASURED COLORIMETRICALLY OR BY GLC WITH ECD. ALTERNATIVELY, GLC WITH ECD MAY BE USED DIRECT.|CHLOROXURON RESIDUES ON SPINACH WERE CONVERTED TO CORRESPONDING CHLOROPHENYL CARBAMATE BY SOXHLET EXTRACTION WITH ETHANOL. CONVERSION ALSO OCCURRED WHEN MONURON WAS REFLUXED WITH OTHER ALCOHOLS, SUCH AS ISOPROPYL & BUTANOL. ALTHOUGH THE CONVERSION DID NOT AFFECT THE ACCURACY OF MONURON DETERMINATION BY THE BRATTON-MARSHALL REACTION, IT WILL AFFECT THE ACCURACY IF THE MEASUREMENT IS CARRIED OUT BY TLC OR PAPER CHROMATOGRAPHY.|Determination of chloroxuron in pesticide formulations by using thin layer chromatographic method. Limit of detection is 0.1% for each byproduct.|For more Analytic Laboratory Methods (Complete) data for CHLOROXURON (8 total), please visit the HSDB record page.

Agrochemicals -> Herbicides|Pharmaceuticals|HERBICIDES