Bifenox

342.13

342.13

255-894-7

KSB85XT26Y

DTXSID1040320

Solid|Yellow tan crystals

2918990090

81.4

4.48

1.155 g/cm³

85 °C

421.0±45.0 °C at 760 mmHg

208.4±28.7 °C

1.608

In water, 0.398 mg/l @ 25 deg C

0-6°C

2.4X10-6 mm Hg @ 25 deg C

Oral-Rat LD50: 6400 mg/kg; Oral-Mouse LD50: 4556 mg/kg

Combustion produces toxic nitrogen oxides and chloride gases

Slightly aromatic odor

Relatively stable to light|Thermally stable up to 175 °C; total decomposition occurs above 290 °C.

...Virtually noncorrosive to most spray equipment materials, but is mildly corrosive to aluminum.

UN30779/PG3

2

50/53

60-61

DG7890000

N

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

Compatible with many other herbicides.

P273-P501

H410

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.

California Environmental Protection Agency/Department of Pesticide Regulation; Toxicology Data Review Summaries. Available from: http://www.cdpr.ca.gov/docs/toxsums/toxsumlist.htm on Bifenox as of March 13, 2003. Provides a summary of available toxicological information for pesticides currently or previously registered for use in California.

|Warning|H400 (100%): Very toxic to aquatic life [Warning Hazardous to the aquatic environment, acute hazard]|P273, P391, and P501|Aggregated GHS information provided by 199 companies from 2 notifications to the ECHA C&L Inventory. Each notification may be associated with multiple companies.|Aggregated GHS information provided by 35 companies from 1 notifications to the ECHA C&L Inventory. Each notification may be associated with multiple companies.

SEDIMENT: Bifenox was detected in the Teufelsweiher pond sediments (pH, 7.8 to 8.1; DOC 41.5 to 50.2) in Scheyern, Upper Bavaria, Germany from 1992-1994 at concns ranging from 4.1 to 18.3 ug/kg in sediment(1).

practically nontoxic

LD50 Rat oral >5000 mg tech./kg|LD50 Mouse oral 4556 mg/kg|LD50 Rabbit percutaneous >2000 mg/kg|LD50 Rat oral >6400 mg/kg

/BIRDS and MAMMALS/ ...American kestrel (Falco sparverius) nestlings were orally dosed for 10 days with 5 ul/g of corn oil (controls) or one of the diphenyl ether herbicides (nitrofen, bifenox, or oxyfluorofen). At 500 mg/kg ...bifenox /resulted/ in high (66%) mortality... . .../For/ bifenox at 250 mg/kg ...crown-rump, humerus, radius-ulna and femur lengths were significantly less than controls. ...Bifenox ingestion (> or =50 mg/kg) resulted in increased hepatic GSH peroxidase activity. ...

Bifenox's production may have resulted in its release to the environment through various waste streams; it's former(2) use as a herbicide(1) resulted in its direct release to the environment(SRC).

TERRESTRIAL FATE: Based on a classification scheme(1), Koc values ranging from 2,658 to 3,107(2), indicates that bifenox is expected to have slight to no mobility in soil(SRC). Volatilization of bifenox from moist soil surfaces is expected to be an environmental fate process(SRC) given an estimated Henry's Law constant of 2.7X10-6 atm-cu m/mole(SRC), based upon its vapor pressure, 2.4X10-6 mm Hg(3), and water solubility, 0.398 mg/l(4); however, adsorption to soil is expected to attenuate volatilization(SRC). Bifenox is not expected to volatilize from dry soil surfaces(SRC) based upon a vapor pressure of 2.4X10-6 mm Hg(3). Bifenox exhibited a half-life of 3 to 7 days following preemergence application to a greenhouse soil(5) and, therefore, biodegradation may be an important environmental fate process in soil.|AQUATIC FATE: Based on a classification scheme(1), Koc values ranging from 2,658 to 3,107(2) indicate that bifenox is expected to adsorb to suspended solids and sediment(SRC). Volatilization from water surfaces is expected(5) based upon a estimated Henry's Law constant of 2.7X10-6 atm-cu m/mole(SRC), derived from its vapor pressure, 2.4X10-6 mm Hg(3), and water solubility, 0.398 mg/l(4). Using this Henry's Law constant and an estimation method(5), volatilization half-lives for a model river and model lake are 25 and 190 days, respectively(SRC). However, volatilization from water surfaces is expected to be attenuated by adsorption to suspended solids and sediment in the water column. The estimated volatilization half-life from a model pond is 3 years if adsorption is considered(10). The major photoreaction pathways observed following solution-phase irradiation at 300 nm of bifenox at 0.25 to 1.0 g/l were decarbomethoxylation, reduction of the nitro substituent to the amino, and cleavage of the ether linkage(11). According to a classification scheme(6), an estimated BCF of 560(SRC), from its log Kow of 4.48(7) and a regression-derived equation(8), suggests the potential for bioconcentration in aquatic organisms is high(SRC). Based on a half-life of 4 days from a field study involving flooded rice paddy soils(9), biodegradation may be an important fate process in anoxic aquatic environments.|ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), bifenox, which has a vapor pressure of 2.4X10-6 mm Hg at 25 °C(2), will exist in both the vapor and particulate phases in the ambient atmosphere. Vapor-phase bifenox is degraded in the atmosphere by reaction with photochemically-produced hydroxyl radicals(SRC); the half-life for this reaction in air is estimated to be 15 days(SRC), calculated from its rate constant of 1.1X10-12 cu cm/molecule-sec at 25 °C(SRC) that was derived using a structure estimation method(3). Particulate-phase bifenox may be removed from the air by wet and dry deposition(SRC).

The rate constant for the vapor-phase reaction of bifenox with photochemically-produced hydroxyl radicals has been estimated as 1.1X10-12 cu cm/molecule-sec at 25 °C(SRC) using a structure estimation method(1). This corresponds to an atmospheric half-life of about 15 days at an atmospheric concentration of 5X10+5 hydroxyl radicals per cu cm(1). A base-catalyzed second-order hydrolysis rate constant of 1.3X10-1 L/mole-sec(SRC) was estimated using a structure estimation method(2); this corresponds to half-lives of 1.6 years and 60 days at pH values of 7 and 8, respectively(2). Radiolabeled bifenox, introduced to a 3-day model rice paddy at a concn of 0.3 ppm, readily hydrolyzed to the corresponding 2,4-dichlorophenyl 3'-carboxy-4'-nitrophenyl ether and was also reduced to 2,4-dichlorophenyl 3'-carboxymethyl-4'-aminophenyl ether(4). A field half-life range of 7-14 days has been reported(5). Products of the photolysis of bifenox include 2,4-dichloro-3'carboxy-4'-nitrodiphenyl ether, nitrofen, p-nitrophenol, p-aminophenol(6). The major photoreaction pathways observed following solution-phase irradiation at 300 nm of bifenox at 0.25 to 1.0 g/l were decarbomethoxylation, reduction of the nitro substituent to the amino, and cleavage of the ether linkage(7).

An estimated BCF of 560 was calculated for bifenox(SRC), using a log Kow of 4.48(1) and a regression-derived equation(2). According to a classification scheme(3), this BCF suggests the potential for bioconcentration in aquatic organisms is high(SRC). However, hydrolysis may attenuate this process(4). Radiolabeled bifenox, introduced to a model 33-day rice paddy ecosystem sand at a 1.29 kg/ha dosage, exhibited a comparatively low ecological magnification value of 49 in mosquito fish (Gambusia) as compared with the other rice paddy herbicides examined in this study, for example 1,546 for nitrofen and 867 formethoxy-nitrofen(4).

1.00e+04 L/kg|Kocs for bifenox have been reported ranging from 2,658 to 3,107(1). According to a classification scheme(2), these Koc values suggest that bifenox is expected to have slight to no mobility in soil. The sorption kinetics for bifenox were characterized by immediate rapid sorption with 30-70% of the added chemical adsorbed within the first 4 hrs, followed by a slow sorption over a longer time period(3). Slight desorption (10%) was noted after 24 hrs(3). In runoff experiments, it was shown that poorly soluble compounds like bifenox are only removed from fields as a result of heavy, erosive rainfalls on areas with a slope >10%; concn in soil before irrigation was 0.78 mg/kg in the 0-5 cm layer, after irrigation concns were in 0.77, 0.01, and 0.01 mg/kg at soil depths of 0-5, 5-10, and 10-15 cm, respectively(4).

The Henry's Law constant for bifenox is estimated as 2.7X10-6 atm-cu m/mole(SRC) derived from its vapor pressure, 2.4X10-6 mm Hg(1), and water solubility, 0.398 mg/l(2). This Henry's Law constant indicates that bifenox is expected to volatilize from water surfaces(3). Based on this Henry's Law constant, the volatilization half-life from a model river (1 m deep, flowing 1 m/sec, wind velocity of 3 m/sec)(3) is estimated as 25 days(SRC). The volatilization half-life from a model lake (1 m deep, flowing 0.05 m/sec, wind velocity of 0.5 m/sec)(3) is estimated as 190 days(SRC). However, volatilization from water surfaces is expected to be attenuated by adsorption to suspended solids and sediment in the water column. The estimated volatilization half-life from a model pond is 3 years if adsorption is considered(4). Bifenox has been shown to hydrolyze rapidly(5) which may negate volatilization as an important fate process. Bifenox did not volatilize from distilled water nor river water under experimental conditions(6). Bifenox's estimated Henry's Law constant indicates that volatilization from moist soil surfaces may occur(SRC). Bifenox is not expected to volatilize from dry soil surfaces(SRC) based upon its vapor pressure(1).

SURFACE WATER: Bifenox was detected in the Teufelsweiher pond in Scheyern, Upper Bavaria, Germany from 1992-1994 at concns ranging from 9.5 to 23 ng/l in pore water(1). A linear correlation was drawn between concentration and dissolved organic carbon(1). Bifenox was not detected (detection limit not specified) in water samples collected at the mouth of the Shinano River in Niigata Prefecture, Japan, where the total amounts of pesticides used annually were 19,000 tons in cultivated areas and 520 tons in noncultivated ares in fiscal year 1995(2).

Bifenox was not detected, detection limit = 0.25 ppm, in 6,970 produce samples (80% domestic, 20% foreign) surveyed in the US from 1989-1991(1).

Occupational exposure and general population exposure should be low or non-existent(SRC) since bifenox is no longer produced or used in the US(1) .|Average concentrations of bifenox on work clothing of tree nursery workers involved in conifer seedling production from 2 different nurseries were 34 (4 of 311 samples pos, scouts whose job it was to examine treated beds daily), 55 (6 of 385 samples pos, weeders), ug/test patch(1). For applicators from both nurseries, results were 109 (9 or 340 samples pos) and 53 (4 of 523 samples pos) ug/test patch(1).

Concentrations of bifenox in urine samples of tree nursery workers (applicators) involved in conifer seedling production ranged from 0.0066 to 0.0287 mg/kg(1).

Bifenox is relatively rapidly absorbed and eliminated from the body; 5-(2,4-dichlorophenyl)-2-nitrobenzoic acid was the major urinary metabolite, with no bifenox detected. Bifenox together with 5-(2,4-dichlorophenyl)anthranilate were detected in feces.|...Bifenox technical grade (98% purity) was administered orally after suspending in 1% carboxymethyl cellulose at 2 g/kg to 6 young adult goats of both sexes for oral kinetics. Blood samples were collected at different time intervals from each goat and concn of bifenox in blood were estimated by GLC. Bifenox in blood was detected at 2 hr (1.32 + or - 0.07 ug/ml) which attained max at 12 hr (6.76 + or - 0.17 ug/ml) followed by gradual decr in concn and reaching at min blood concn at 24 hr. The kinetic behavior of bifenox followed "two compartment open model". The .../volume of distribution/ area and /blood clearance/ values were ...2.73 + or - 0.28 l/kg and 0.88 + or - 0.07 l/kg/hr respectively, indicating wide distribution and shorter persistence in the body.

...Bifenox technical grade (98% purity) was administered orally after suspending in 1% carboxymethyl cellulose at 2 g/kg to 6 young adult goats of both sexes for oral kinetics. ...The t1/2... /was/ 2.04 + or - 0.04 hr... .

Basic treatment: Establish a patent airway. 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 normal saline 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 ... . /Poison A and B/|Advanced treatment: Consider orotracheal or nasotracheal intubation for airway control in the patient who is unconscious, has severe pulmonary edema, or is in respiratory arrest. Positive pressure ventilation techniques with a bag valve mask device may be beneficial. Monitor cardiac rhythm and treat arrhythmias as necessary ... . Start an IV with D5W /SRP: "To keep open", minimal flow rate/. Use lactated Ringer's if signs of hypovolemia are present. Watch for signs of fluid overload. Consider drug therapy for pulmonary edema ... . For hypotension with signs of hypovolemia, administer fluid cautiously. Watch for signs of fluid overload ... . Treat seizures with diazepam (Valium) ... . Use proparacaine hydrochloride to assist eye irrigation ... . /Poison A and B/

2,4-dichlorophenyl-3'-carboxymethyl-4'-nitrophenyl ether

Principal tradename 'Modown' (Rhone-Poulenc), 'Tolkam Fox' (Rhone-Poulenc). Mixtures (bifenox +) mecoprop; linuron; chlortoluron; propanil; clopuralid + mecoprop; isoproturon + mecoprop; ioxynil + mecoprop; isoproturon + neburon.

The WHO Recommended Classification of Pesticides by Hazard identifies Bifenox (technical grade) as unlikely to present an acute hazard in normal use; Main Use: herbicide.|Based on 1987 usage data, 125,224 lbs active ingredient were applied to 3% of the rice crop in Louisiana.

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

Bifenox has known environmental transformation products that include bifenox acid.|Bifenox has known environmental transformation products that include LS 825055 Bifenox acid, RPA 405912, and RPA 408354.