Bentazon

240.28

240.28

246-585-8

R4S7ZGZ9CT

0828

DTXSID0023901

Colorless crystals; tech. is an ochre-yellow solid [|White, crystalline powder

2934999027

74.9

-0.46

White Solid

1.41 g/cm³ @ Temp: 20 °C

139.4-141 °C

395.7±25.0 °C at 760 mmHg

2 °C

1.583

Solubility in water: none

APPROX 4°C

Vapour pressure, Pa at 20°C:

Oral-Rat  LD50: 1100 mg/kg

Combustion produces toxic nitrogen oxide and sulfur oxide gas

Odorless

pKa = 3.3 at 24 °C|Dissociation constant: pKa = 2.92 at 20 °C

147.66 Ų [M-H]-

Slightly brown solid /Technical bentazon/|Kow logP = 0.77 (pH 5), -0.46 (pH 7), -0.55 (pH 9)|Very resistant to hydrolysis in both acidic and alkaline media. Decomposed by sunlight

Not corrosive

III

6.1

UN16483/PG2

2

22-36-43-52/53-20/21/22-11

2-24-37-61-36-26-16

DK9900000

Xn,F

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

Very resistant to hydrolysis. In 0.1 N sodium hydroxide and in 0.1 N hydrochloric acid, no degradation observed after 48 hr. In UV light, 50% decomp occurs in 13.3 hr.

P273-P280-P305 + P351 + P338

H302-H317-H319-H412

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. Contact a licensed professional waste disposal service to dispose of this material; Contaminated packaging: Dispose of as unused product.|Group I Containers: Combustible containers from organic or metallo-organic pesticides (except organic mercury, lead, cadmium, or arsenic compounds) should be disposed of in pesticide incinerators or in specified landfill sites. /Organic or metallo-organic pesticides/|Group II Containers: Non-combustible containers from organic or metallo-organic pesticides (except organic mercury, lead, cadmium, or arsenic compounds) must first be triple-rinsed. Containers that are in good condition may be returned to the manufacturer or formulator of the pesticide product, or to a drum reconditioner for reuse with the same type of pesticide product, if such reuse is legal under Department of Transportation regulations (eg 49 CFR 173.28). Containers that are not to be reused should be punctured ... and transported to a scrap metal facility for recycling, disposal or burial in a designated landfill. /Organic or metallo-organic pesticides/

USEPA/Office of Prevention, Pesticides and Toxic Substances; Reregistration Eligibility Decision Document for Bentazon EPA 738-R-94-029 (September 1994). 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 October 26, 2017: http://www.epa.gov/pesticides/reregistration/status.htm]|WHO/IPCS; Pesticide Residues in Food - 1991. Part II - Toxicology (1992)

Liquid formulations containing organic solvents may be flammable. Gives off irritating or toxic fumes (or gases) in a fire. Risk of fire and explosion if formulations contain flammable/explosive solvents.

|Warning|H302: Harmful if swallowed [Warning Acute toxicity, oral]|P261, P264, P270, P272, P273, P280, P301+P312, P302+P352, P305+P351+P338, P321, P330, P333+P313, P337+P313, P363, and P501|H302 (100%): Harmful if swallowed [Warning Acute toxicity, oral]|Aggregated GHS information provided by 346 companies from 2 notifications to the ECHA C&L Inventory. Each notification may be associated with multiple companies.|Danger|P261, P264, P270, P273, P280, P285, P301+P312, P304+P341, P305+P351+P338, P330, P337+P313, P342+P311, and P501

Eye/face protection: Face shield and safety glasses. 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: Complete suit protecting against chemicals. The type of protective equipment must be selected according to the concentration and amount of the dangerous substance at the specific workplace.|Respiratory protection: For nuisance exposures use type P95 (US) or type P1 (EU EN 143) particle respirator. For higher level protection use type OV/AG/P99 (US) or type ABEK-P2 (EU EN 143) respirator cartridges. Use respirators and components tested and approved under appropriate government standards such as NIOSH (US) or CEN (EU).|Chemical-resistant apron when cleaning equipment, mixing, or loading. Chemical-resistant gloves. Protective eyewear. Protective clothing and boots when handling undiluted product.

Suitable extinguishing media: Use water spray, alcohol-resistant foam, dry chemical or carbon dioxide.|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: Avoid contact with skin and eyes. Avoid formation of dust and aerosols. 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 Bentazon (6 total), please visit the HSDB record page.

Bentazone is not a skin irritant but was a moderate eye irritant in rabbits.|Irritating to eyes and mucous membranes.

Do NOT wash away into sewer. Sweep spilled substance into covered containers. If appropriate, moisten first to prevent dusting. Carefully collect remainder. Then store and dispose of according to local regulations. Personal protection: chemical protection suit including self-contained breathing apparatus.

Provision to contain effluent from fire extinguishing. Separated from food and feedstuffs.

Evaporation at 20 °C is negligible; a harmful concentration of airborne particles can, however, be reached quickly on spraying or when dispersed, especially if powdered.

The substance is irritating to the eyes.

AVOID EXPOSURE OF ADOLESCENTS AND CHILDREN!

Avoid inhalation of dust and mist. Use local exhaust or breathing protection.

Protective gloves.

Wear safety goggles.

RURAL/REMOTE: Bentazon was not detected in ambient air samples collected weekly over an 8-week period from May to September 2004 at St. Damase located in the mid-watershed of the Yamaska River, Quebec(1).

moderately

IDENTIFICATION AND USE: Bentazone is a white, crystalline solid. It was formerly used as an herbicide. HUMAN STUDIES: Bentazone is irritating to eyes and mucous membranes. A 50-year-old male who had sprayed corn with a solution of bentazone was admitted to the hospital with sweating, fever, nausea, vomiting of aqueous and hemorrhagic content, and bloody, watery stools. He was treated according to the symptoms including extracorporeal hemodialysis, but eventually suffered from multiorgan failure (acute respiratory failure, acute liver failure, coagulopathy, acute renal failure, metabolic acidosis, and gastrointestinal bleeding) and died 11.35 hr after admittance. In another case, intentional poisoning with 130 g of bentazone resulted in vomiting, fever, sweating, pipe-like muscle rigidity, sinus tachycardia, drowsiness, leukocytosis, rhabdomyolysis and hepatorenal damage. ANIMAL STUDIES: Bentazone is not a skin irritant but was a moderate eye irritant in rabbits. It is a skin sensitizer in guinea-pigs. In a chronic toxicity study, bentazone was administered to rats (50 of each sex per group) via a diet at doses 0, 5, 17 and 76 mg/kg bw per day for 2 years. Statistical analysis of tumor incidence did not reveal any significance among the groups tested. Bentazone was not teratogenic in rabbits or rats. In rat developmental studies, it increased post-implantation loss, skeletal variations (incomplete or absent ossification in the phalangeal nuclei of the extremities, sternebrae and cervical vertebrae) and reduced body weights of fetuses surviving to day 21 at 250 mg/kg bw per day. Dietary administration of bentazone to rats at dose levels of 0, 300, 1000 and 3500 ppm did not result in any indication of neurotoxicity. In vitro genotoxicity studies included bacterial reverse mutation assays on Salmonella typhimurium and Escherichia coli, DNA damage and repair studies on E. coli and Saccharomyces cerevisiae, and chromosomal aberration and forward mutation assays in CHO cells. In vivo studies included chromosome analyses in mice and rats, unscheduled DNA synthesis tests in mice, and mutation assays in germ cells for mice and rats. Bentazone gave negative results in all of these studies. ECOTOXICITY STUDIES: Bentazone affected zebrafish embryos and associated bacterial communities. It was nontoxic to bees.

Maize black Mexican sweet cell suspension cultures were used to study the effects of various cytochrome p450 monooxygenase inhibitors on the uptake and metabolism of the herbicide bentazon. Maize cells rapidly absorbed bentazon and metabolized it via aryl hydroxylation and glycosylation to a glycosyl conjugate of 6-hydroxybentazon. Maize black Mexican sweet cells accumulated bentazon to levels approximately 20 fold greater than those in the external medium. When maize black Mexican sweet cells were incubated in an external medium containing 25 uM bentazon, the formation of the glycosyl conjugate (ca 2 nmol/min/g fresh wt) was rate limited by aryl hydroxylation. Tetcyclacis, a plant growth retardant, phenylhydrazine, a mechanism based cytochrome p450 inhibitor, and piperonyl butoxide, an insecticide synergist, inhibited bentazon metabolism with I50 values of approximately 0.1, 1.0, and 1.0 uM, respectively. Other mechanism based cytochrome p450 inhibitors, 3(2,4-dichlorophenoxy)-1-propyne and aminobenzotriazole, also inhibited bentazon metabolism but were less effective. The results obtained with selected inhibitors are consistent with the hypothesis that aryl hydroxylation of bentazon is catalyzed by a cytochrome p450 monooxygenase.

LD50 Rat oral 850-2470 mg/kg bw /Includes free acid and sodium salt forms; From table/|LD50 Guinea pig oral 1100 mg/kg bw /Free acid and sodium salt forms; From table/|LD50 Rabbit oral 1139 mg/kg bw /From table/|LD50 Rat dermal >5000 mg/kg bw /Acid form; From table/|For more Non-Human Toxicity Values (Complete) data for Bentazon (26 total), please visit the HSDB record page.

/AQUATIC SPECIES/ This study aimed to assess the effects of Basagran on zebrafish (Danio rerio) embryos. The embryos were exposed to Basagran at concentrations ranging from 120.0 to 480.6 mg/L, and the effects on embryo development (up to 96 hr) and bacterial communities of 96 hr-larvae were assessed. The embryo development response was time-dependent and concentration-dependent (106.35 < EC50 < 421.58 mg/L). The sensitivity of embryo-related endpoints decreased as follows: blood clotting in the head and/or around the yolk sac > delay or anomaly in yolk sac absorption > change in swimming equilibrium > development of pericardial and/or yolk sac edema > scoliosis. A PCR-DGGE analysis was used to evaluate changes in the structure, richness, evenness and diversity of bacterial communities after herbicide exposure. A herbicide-induced structural adjustment of bacterial community was observed. In this study, it was successfully demonstrated that Basagran affected zebrafish embryos and associated bacterial communities, showing time-dependent and concentration-dependent embryos' developmental response and structural changes in bacterial community. Thus, this work provides for the first time a complementary approach, which is useful to derive robust toxicity thresholds considering the embryo-microbiota system as a whole. The aquatic hazard assessment will be strengthened by combining current ecotoxicological tests with molecular microbiology tools.|/OTHER TERRESTRIAL SPECIES/ /Nontoxic to bees./|/OTHER TOXICITY INFORMATION/ The toxicological effects of the active ingredients of the herbicides diuron and bentazon on the activity of acetylcholinesterase (AChE) of krait (Bungarus sindanus) venom and electric eel (Electrophorus electricus) were studied. The diuron and bentazon caused non-competitive inhibition of AChE from both species. For the venom AChE, the calculated IC50 for diuron and bentazon were found to be 3.25 and 0.14 uM, while for eel AChE, the respective IC50 values were 3.6 and 0.135 uM. In comparison, bentazon was a more potent inhibitor than diuron of AChE from both species. The insecticide lindane did not have any inhibitory effect on AChE activity in either species, even when tested at high concentrations (200-800 uM).

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

TERRESTRIAL FATE: Based on a classification scheme(1), a Koc range of 0 to 46(2,3) indicates that bentazon is expected to have very high to high mobility in soil(SRC). The pKa of bentazon is 3.3(4), indicating that this compound will exist almost entirely in 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 from moist soil is not expected because the compound exists as an anion and anions do not volatilize. Bentazon is not expected to volatilize from dry soil surfaces(SRC) based upon a vapor pressure of 4.05X10-8 mm Hg at 20 °C(2). In aerobic soils, reported degradation half-lives of 6.7 to 50 days(2,6) suggests that under certain conditions biodegradation may be an important environmental fate process in soil(SRC).|FIELD STUDY: Field dissipation studies were conducted in Texas on sandy soil (0.5% OM) planted with peanuts, Mississippi on a Commerce silt loam soil planted with soybeans and peanuts, Mississippi on a Sharkey silty clay loam soil planted with soybeans, North Carolina on acidic, sandy loam soil (2.8% OM) planted to peanuts, Minnesota on clay soil planted to soybeans, and Idaho on a sandy loam soil. Bentazon, applied as a wettable powder or soluble concentrate at cumulative rates of 1.0 to 10 lbs a.i./A, had field dissipation half-lives of 7 to 33 days. The degradate AIBA was detected (< 0.05 ppm) in the North Carolina, Mississippi, Alabama, and Idaho field dissipation studies. Bentazon and 2-amino-N-isopropylbenazamide were not detected in deep soil samples (> 12 inches of soil) in field studies.|AQUATIC FATE: Based on a classification scheme(1), a Koc range of 0 to 46(2,3) indicates that bentazon is not expected to adsorb to suspended solids and sediment(SRC). A pKa of 3.3(4) indicates bentazon 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). According to a classification scheme(5), a whole body BCF of 3.7 in bluegill sunfish(6), suggests the potential for bioconcentration in aquatic organisms is low(SRC). Complete photolysis of bentazon took place within 16 hours in distilled water at pH 6.8 when irradiated with UV light(7,8). Bentazon was not degraded in biodegradation experiments anaerobic aquifer conditions(9) but the available soil studies would suggest that biodegradation may 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), bentazon, which has a vapor pressure of 4.05X10-8 mm Hg at 20 °C(2), is expected to exist solely in the particulate phase in the ambient atmosphere. Particulate-phase bentazon may be removed from the air by wet and dry deposition(SRC). Bentazon absorbs light at wavelengths between 330 and 335 nm(3) and, therefore, may be susceptible to direct photolysis by sunlight, since sunlight consists of wavelengths above 290 nm(SRC).

Based on its vapor pressure of 4.05X10-8 at 20 °C(1), bentazon is expected to exist solely in the particulate phase in the ambient atmosphere. Particulate-phase bentazon will be removed from the air by wet and dry deposition. Bentazon is not expected to undergo hydrolysis in the environment; bentazon was stable to hydrolysis in pH 5, 7, and 9 buffer solutions(2). Bentazon absorbs light at wavelengths between 330 and 335 nm(3) and, therefore, is expected to be susceptible to direct photolysis by sunlight, since sunlight consists of wavelengths above 290 nm(SRC). Bentazon undergoes rapid degradation in sunlight, ultimately to CO2(1). Photodegration half-lives in soil and water have been measured as 63 hours and 941 hours, respectively(2).

Following an EPA guideline study, a whole body BCF of 3.7 was reported for bentazon in bluegill fish (Lepomic macrochirus) exposed for 28 days(1). According to a classification scheme(2), this BCF suggests the potential for bioconcentration in aquatic organisms is low(SRC). The BCF for 14C-bentazon residues in bluegill sunfish was 0.4 in edible fish tissue, 2.3 in non-edible fish tissues, and 1.4 in the whole body. In channel catfish, the maximum concentration of 14C-bentazon residues was 11.39 ug/g in non-edible tissues, 8.84 ug/g in whole tissues, and 2.47 ug/g in edible tissues(3).

33.11 L/kg|The Koc of bentazon is reported as 13.3-176 mL/g with an average of 42 mL/g(1). Experimental soil adsorption coefficients of 0(2) and 33(3) have been reported. According to a classification scheme(4), these Koc values suggest that bentazon is expected to have very high to high mobility in soil. The pKa of bentazon is 3.3(5), indicating that this compound will exist almost entirely in anion form in the environment and anions generally do not adsorb more strongly to soils containing organic carbon and clay than their neutral counterparts(6). It has been reported that, when used according to good agricultural practice, bentazone is degraded more quickly than it can leach; in lysimeter studies, average annual leachates contained <0.1 ug/L(1). Batch equilibrium studies, using conventional-till Dundee silt loam soil, with an organic carbon content of 0.64 and a pH of 5.77, reveal limited sorption of bentazon(7). Bentazon sorption was not affected by small differences in soil organic matter(7). Bentazon was poorly adsorbed in ten soils from Spain(8). A Pesticide Leaching Potential(PLP) Index of 50 for foliar application was calculated for bentazon using commonly reported Koc, persistence (half-life), and rate of application values(9,10). PLP values of 0 and 100 indicate no leaching potential and maximum leaching potential, respectively(9).|Based on Kd values of 0.176 to 3.056, binding affinity to soil expected to be low. Bentazon may be expected to leach into ground and enter runoff to surface waters. Bentazon degradates N-methyl-bentazon and 8-chlorobentazon are relatively immobile in soil. The degradate 2-amino-N-isopropylbenazamide (AIBA) is mobile and nonpersistent in soil. Terrestrial field studies indicate bentazon dissipates rapidly in soils with reported half-lives of < 33 days under typical use conditions and leaching did not appear to be a major route of dissipation(1).

A pKa of 3.3(1) indicates bentazon 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. Bentazon is not expected to volatilize from dry soil surfaces(SRC) based upon a vapor pressure of 4.05X10-8 mm Hg(2).

GROUND WATER: A pesticide detection study conducted in the Arkansas Delta analyzed groundwater samples collected from 77 irrigation wells between July 29 and September 23, 1996(1). Bentazon was the most frequently detected pesticide, accounting for 37% of total detections, with concentrations ranging from 0.0144 to 0.1153 ug/L. In a study seeking to characterize potential pesticide contamination of groundwater in eastern Arkansas, 231 wells located within 14 counties were sampled(2). Of the 231 wells sampled, only 17 had detectable pesticide concentrations. Bentazon was the most commonly detected pesticide occurring in 11 of the 17 contaminated wells with a concentration range of 0.2 to 152.1 ug/L. Bentazon was detected in 26 upper groundwater (below 3 meters) samples in the Netherlands at an average concentration of 0.2 ug/L(3). Bentazon has been detected in groundwater (maximum concentration in ug/L) in Germany(0.04), Italy(40), and in the Netherlands(1.1)(4). In a review of published Italian water monitoring papers from 1997 to 2013, bentazon was identified as one of the most detected herbicides in Italian ground waters with a maximum concentration of 16000 ng/L(5).|GROUND WATER: Bentazon has been detected at concentrations ranging from 0.01 to 120 parts per billion (ppb) in 11% (83 out of 750) of wells sampled from California, with the greatest number of detections (64 out 0f 200; from 0.01 to 20.0 ug/L), Florida, Missouri, and Virginia; wells were sampled without detections in Louisiana (0 out of 3) , Mississippi (0 out of 120) , Oregon (0 out of 44) , and Washington (0 out of 81); dates were not reported. In Florida, bentazon was detected at concentrations of 3.3 to 120 ug/L in 3 of 24 samples collected from four shallow wells located near greens and tees at six golf courses; dates not reported. In the 3700 acre Nomini Creek Watershed, Westmoreland County, VA, bentazon was detected at concentrations of 0.07 to 0.547 ug/L in 5 of 12 wells (4 household wells and 8 monitoring wells). In Missouri, bentazon was detected at concentrations from 0.6 to 1.0 ug/L in 5 out of 266 private rural wells located in three agricultural counties(1).|GROUND WATER: Water quality data compiled from the Retrieval (STORET) Data Warehouse and the USGS National Water Information System (NWIS) reports ground water monitoring data. USGS Water Science Center monitoring sites in several states as well as sites such as the Minnesota Department of Agriculture - Pesticide Monitoring report data for bentazon. Select data from the 2010 to 2017 monitoring years follows(1).[Table#4598]|DRINKING WATER: Bentazon was detected in 4 out of 240 well water samples from rural Illinois, at concentrations ranging from 1.7 to 10 ug/L(1). In the National Survey of Pesticides in Drinking Water Wells, conducted by the U.S. EPA, it was estimated that 7160 rural domestic wells contain bentazon(2). Bentazon was detected in 64 water wells in California between 1975-1991 with a maximum concentration of 20 ug/L(3). Bentazon was detected in well water in rural Missouri at a concentrations of 1 ppb(4). In a U.S. national survey of wells, bentazon was detected in a total of 80 water samples between 1981-1990 with concentrations ranging from 0.1 to 41.89 ug/L(5).|For more Environmental Water Concentrations (Complete) data for Bentazon (8 total), please visit the HSDB record page.

Bentazon was not included in the U.S Food and Drug Administration Total Diet Study Market Baskets 2004 through 2005(1).

In 2010, bentazone was not detected in bovine raw milk (n=100) from a local farm, and full-fat milk (n=30), half-skimmed milk (n=20), and skimmed milk (n=20) from a local supermarket, near Shenyang Agricultural University, China(1).

Occupational exposure to bentazon may occur through inhalation of dust and dermal contact with this compound at workplaces where bentazon is produced or used. Limited monitoring and use data indicate that the general population may be exposed to bentazon via ingestion of contaminated water. (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.)

Toxicokinetic studies performed on mice, rats and rabbits indicate that bentazone is rapidly and almost completely absorbed via the oral route (> 99%), and maximum blood concentrations of radioactivity are achieved in approximately 15 minutes at low doses (4 mg/kg bw) and by 1 hour at high doses (200 mg/kg bw). Administration of bentazone either as the sodium salt or as the free acid did not result in any significant differences in absorption. There was no evidence of penetration into the central nervous system or spinal cord, and elimination from other tissues was rapid, with no indication of bioaccumulation. Elimination was almost exclusively via the urine (approximately 91% within 24 hours); 5 days after dosing, less than 2% was found in feces and less than 0.02% in expired air. Biliary excretion of radioactivity was minimal. No significant differences were found in absorption and elimination among the different species investigated (rat, rabbit, mouse).|The dermal penetration of [14C]bentazone sodium salt (batch no. 210-2201, radiochemical purity 97.3%) through human skin was assessed by a single topical application of about 4933, 49.3 or 8.22 ug/sq cm of active ingredient formulated in BAS 351 32 H to split thickness skin membranes mounted on Franz-type diffusion cells. The doses represent the formulation concentrate or two representative spray dilutions (1:100 and 1:600) for field use, respectively. The study was performed using five diffusion cells per dose. ... It can be concluded that in vitro dermal penetration of bentazone formulated as an aqueous soluble (liquid) concentrate formulation of bentazone sodium through human skin is appropriately calculated as per cent absorbed dose. Considering the amount of radiolabeled substance associated with the skin (remaining skin and tape strips 3-6) after washing as absorbable and combining this with the absorbed amount detected in the receptor, the extent of dermal penetration through human epidermis is about 0.06% for the concentrate, 1.31% for the 1:100 spray strength dilution and 1.23% for the 1:600 dilution. /Bentazone sodium salt/|A case of fatal suicidal bentazone poisoning was presented along with a description of the different analytical methods involved. A 56-year-old farmer was examined by the family doctor 1 hour after voluntarily ingesting 500 mL of FIGHTER (about 250 g bentazone). He presented a Glasgow score of 15, polypnea, diarrhea and vomiting. During transport by ambulance to the hospital, he tossed, sweated and suddenly presented breathing difficulty followed by heart failure. The patient died within 2 hours post-ingestion. Blood and urine samples were taken just before death. Bentazone plasma and urine levels were 1500 and 1000 mg/L, respectively.|A 59-year-old woman who intentionally ingested 100-200 mL Basagran (about 50-100 g bentazone) was taken to the hospital with cardiac arrest 2 days after she had consumed the herbicide. During this period, she suffered vomiting, urination and diarrhoea, and she was drowsy with a muddled speech. Biological samples obtained at the autopsy were analysed, and the presence of bentazone, alcohol and an active metabolite of citalopram was detected. Blood concentrations of bentazone, alcohol and desmethyl-citalopram were 625 mg/kg, 0.62 g/L and 0.03 mg/kg, respectively.

The metabolism of bentazone was investigated in a number of toxicokinetic studies following oral (rat and rabbit) or intravenous administration (mouse) ... . Bentazone was only poorly metabolized, with the parent compound being the predominant excretion product. Only small amounts of 6-hydroxybentazone and 8-hydroxybentazone could be detected. In rats, rabbits and mice, no conjugated products were found.|6-Hydroxybentazone and 8-hydroxybentazone are major plant metabolites of bentazone. Because crops of treated plants can be consumed by humans, farm animals or pets, an exposure to both of these compounds might be expected in principle. Although both metabolites have been demonstrated to be formed in mammals and therefore can be regarded as included in toxicological testing of the parent compound, specific toxicological studies were performed. It has been shown that the 8-hydroxy and 6-hydroxy metabolites of bentazone are of comparable toxicity by the oral route of administration and are both less toxic than the parent compound. Additionally, both metabolites were negative in the Ames assay for the potential to induce point mutations in bacteria. As it is unlikely that a hydroxy group shift in the bentazone ring system dramatically changes the toxicity, it was decided to perform further investigations on 8-hydroxybentazone as a reference substance. Therefore, 8-hydroxybentazone was investigated in a subchronic feeding study, in several mutagenicity studies and in a prenatal developmental study. These investigations revealed that the metabolites have no mutagenic or teratogenic potential and are less toxic than the parent substance.|In studies with soybeans [Glycine max (Leguminatae) Merr.] and navy beans (Phaseolus vulgaris Leguminatae), four unidentified conjugates were observed. After foliar or root absorption, bentazon was rapidly metabolized by soybeans with hydroxylation at the 6 and 8 position. These were conjugated. Analysis of soybean field samples showed hydroxylation of bentazon in early growth stages.|Although absorption and translocation of bentazon was not markedly different in resistant rice and susceptible C. serotinus, metabolism differed markedly. In rice, there was 80% metabolism of absorbed bentazon within 24 hr and 85% conversion to a major water soluble metabolite within 7 days. In C. serotinus, there was only 25-50% metabolism of bentazon in 7 days. Similar results were obtained with other resistant and susceptible plant species indicating that ability to metabolize this compound is the primary mechanism of selectivity. The primary metabolite in rice was identified by GC-MS, NMR and IR as 6-(bentazon)-O-beta-glucopyranoside. Other studies showed that the 6- and 8-hydroxybentazon were formed in about equal amounts in soybeans and that the 6-hydroxy analog predominates in wheat, rice, peanuts, Senecio sp., and Chenopodium sp.|For more Metabolism/Metabolites (Complete) data for Bentazon (8 total), please visit the HSDB record page.

Inhibition of photosynthesis at photosystem II.

Fresh air, rest. Refer for medical attention.

Remove contaminated clothes. Rinse and then wash skin with water and soap.

First rinse with plenty of water for several minutes (remove contact lenses if easily possible), then refer for medical attention.

/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 ... . /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/|Decontaminate skin promptly by washing with soap and water. Treat contamination of the eyes immediately by prolonged flushing with copious amounts of clean water. If dermal or ocular irritation persists, medical attention should be obtained without delay. /Other herbicides/|For more Antidote and Emergency Treatment (Complete) data for Bentazon (7 total), please visit the HSDB record page.

/SIGNS AND SYMPTOMS/ Irritating to eyes and mucous membranes.|/CASE REPORTS/ This study presents two cases of lethal bentazone poisonings, their clinical presentation, the course of the disease and the autopsy findings. The first is a 50-year-old male who had sprayed corn with a solution of bentazone and was admitted to the hospital with sweating, fever, nausea, vomiting of aqueous and hemorrhagic content, and bloody, watery stools. He was treated according to the symptoms including extracorporeal hemodialysis, but eventually suffered from multiorgan failure (acute respiratory failure, acute liver failure, coagulopathy, acute renal failure, metabolic acidosis, and gastrointestinal bleeding) and died 11.35 hr after admittance. The cause of death was probable bentazone intoxication. The second case, also a male, aged 49 who committed suicide by ingesting a bentazone solution. He was transferred to the hospital prostrated and cyanotic and died 14.15 hr after admittance despite all efforts by the hospital staff. The cause of death was acute bentazone intoxication.|/CASE REPORTS/ A 27-year-old robust man, without any medical or surgical history, attempted to commit suicide by consuming 300 mL Basagran (about 130 g bentazone). This poisoning resulted in vomiting, fever, sweating, pipe-like muscle rigidity, sinus tachycardia, drowsiness, leukocytosis, rhabdomyolysis and hepatorenal damage. Empirical treatment with bromocriptine was temporally associated with resolution of the above signs and symptoms. His clinical presentations and the effect of bromocriptine may be indicative that Basagran poisoning mimicks neuroleptic malignant syndrome.|/CASE REPORTS/ A case of fatal suicidal bentazone poisoning was presented along with a description of the different analytical methods involved. A 56-year-old farmer was examined by the family doctor 1 hour after voluntarily ingesting 500 mL of FIGHTER (about 250 g bentazone). He presented a Glasgow score of 15, polypnea, diarrhea and vomiting. During transport by ambulance to the hospital, he tossed, sweated and suddenly presented breathing difficulty followed by heart failure. The patient died within 2 hours post-ingestion. Blood and urine samples were taken just before death. Bentazone plasma and urine levels were 1500 and 1000 mg/L, respectively.|For more Human Toxicity Excerpts (Complete) data for Bentazon (9 total), please visit the HSDB record page.

Basagran

The substance can be absorbed into the body by inhalation and by ingestion.

Redness. Pain.

UPI Bentazon Technical (United Phosphorus, Inc.): Active ingredient: bentazon 98.6%.|Bentazon Technical (Sharda Cropchem Limited): Active ingredient: bentazon 98.6%.|Sharda Bentazon 5L (Sharda USA LLC): Active ingredient: bentazon 53.0%%.|Bentazon Technical (Redeagle International LLC): Active ingredient: bentazon 98.9%.|For more Formulations/Preparations (Complete) data for Bentazon (7 total), please visit the HSDB record page.

1H-2,1,3-Benzothiadiazin-4(3H)-one, 3-(1-methylethyl)-, 2,2-dioxide: ACTIVE|The WHO Recommended Classification of Pesticides by Hazard identifies bentazone (technical grade) as Class II: moderately hazardous; Main Use: herbicide.

Method: USGS-NWQL O-2060-01; Procedure: high performance liquid chromatography-mass spectrometry; Analyte: bentazon; Matrix: water; Detection Limit: 0.0055 ug/L.|Method: USGS-NWQL O-1131-95; Procedure: high performance liquid chromatography; Analyte: bentazon; Matrix: natural water; Detection Limit: 0.014 ug/L.|Method: EPA-TSC/NERL 515.1; Procedure: gas chromatography with an electron capture detector; Analyte: bentazon; Matrix: ground water and finished drinking water; Detection Limit: 0.11 ug/L.|Method: EPA-RCA 8151A; Procedure: gas chromatography with an electron capture detector; Analyte: bentazon; Matrix: water, soil, and waste samples; Detection Limit: 0.2 ug/L.|For more Analytic Laboratory Methods (Complete) data for Bentazon (17 total), please visit the HSDB record page.

Agrochemicals -> Herbicides|Pharmaceuticals|Herbicides|Environmental transformation -> Pesticides (parent, predecessor)

Bentazone has known environmental transformation products that include 2-amino-N-isopropylbenzamide and N-methyl bentazone.|Bentazone has known environmental transformation products that include 6-OH-bentazone, 6-bromo-bentazone, 6-chloro-bentazone, 8-OH-bentazone, 8-bromo-bentazone, 8-chloro-bentazone, and N-methyl Bentazone.