Bifenazate

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.

Tolerances are established for residues of bifenazate (1-methylethyl 2-(4-methoxy[1,1'-biphenyl]-3-yl)hydrazinecarboxylate) including its metabolites and degradates, in or on the commodities listed in the following table. Compliance with the tolerance levels specified are to be determined by measuring only the sum of bifenazate and its metabolite, diazinecarboxylic acid, 2-(4-methoxy-[1,1'-biphenyl]-3-yl), 1-methylethyl ester, (calculated as the stoichiometric equivalent of bifenazate) in or on the following food commodities:[Table#6591]

Tolerances are established for residues of bifenazate (1-methylethyl 2-(4-methoxy[1,1'-biphenyl]-3-yl) hydrazinecarboxylate) including its metabolites and degradates, in or on the commodities listed in the following table. Compliance with the tolerance levels specified are to be determined by measuring only the sum of bifenazate and its metabolites diazinecarboxylic acid, 2-(4-methoxy-[1,1'-biphenyl]-3-yl), 1-methylethyl ester; 1,1'-biphenyl, 4-ol; and 1,1'-biphenyl, 4-oxysulfonic acid (calculated as the stoichiometric equivalent of bifenazate) in or on the following food commodities:[Table#6592]

Tolerances with regional registration, as defined in section 180.1(l), are established for residues of bifenazate (1-methylethyl 2-(4-methoxy[1,1'-biphenyl]-3-yl)hydrazinecarboxylate) including its metabolites and degradates, in or on the commodities listed in the following table. Compliance with the tolerance levels specified are to be determined by measuring only the sum of bifenazate and its metabolite, diazinecarboxylic acid, 2-(4-methoxy-[1,1'-biphenyl]-3-yl), 1-methylethyl ester, (calculated as the stoichiometric equivalent of bifenazate) in or on the following food commodities:[Table#6593]

... The ability of well-known organophosphates and carbamates to inhibit the activation of bifenazate and thus compromise its acaricidal potential was tested. Esterase activity determined in vivo after pre-exposure of mites with organophosphates and carbamates revealed-depending on the compound-varying esterase inhibition nicely correlated with the ability of the individual compound to antagonise bifenazate action on mites. The findings illustrate that organophosphates and carbamates interfere with bifenazate efficacy, most probably by inhibiting carboxylesterases responsible for the activation of the pro-drug. As a result of the strong antagonism, mixtures of bifenazate with carbamates or organophosphates should not be used under field conditions. Moreover, there exists a real threat in repeatedly applying organophosphates and bifenazate. The present study again illustrates how important mode of action information is for the proper planning of resistance management strategies.

LD50; Species: /Apis mellifera/ (Bee) contact 8.5 ug/bee for 48 hr

LC50; Species: Anas platyrhynchos (Mallard duck) age 10 days; dietary (in food) 656 ppm for 8 days (95% confidence interval: 463-932 ppm)

LC50; Species: Colinus virginianus (Northern Bobwhite Quail) age 10 days; dietary (in food) 1862 ppm for 8 days (95% confidence interval: 1428-2524 ppm)

LD50; Species: Colinus virginianus (Northern Bobwhite Quail) age 25 weeks; oral via capsule 1032 mg/kg (95% confidence interval: 759-1624 mg/kg)

For more Ecotoxicity Values (Complete) data for Bifenazate (15 total), please visit the HSDB record page.

TERRESTRIAL FATE: Based on a classification scheme(1), Koc values of 1,780 to 6,189(2,3), indicate that bifenazate is expected to have low to no mobility in soil(SRC). The pKa of bifenazate is 12.94(4), indicating that this compound will exist almost entirely in cation form in the environment and cations generally adsorb more strongly to soils containing organic carbon and clay than their neutral counterparts(5). Volatilization of bifenazate from moist soil surfaces is not expected to be an important fate process(SRC) given an estimated Henry's Law constant of 7.9X10-9 atm-cu m/mole(SRC) derived from its vapor pressure, 7.5X10-8 mm Hg(4), and water solubility, 3.76 mg/L(6). Additionally, volatilization from moist soil is not expected because the compound exists as cation and cations do not volatilize. Bifenazate is not expected to volatilize from dry soil surfaces(SRC) based upon its vapor pressure and cationic nature under environmental conditions. Utilizing the Modified Sturm test, 11.7% CO2 evolution was reached in 28 days therefore bifenazate is not considered readily biodegradable. Aerobic half-lives in water/sediment systems are reported as less than 6 hours to 7.3 hours with 18.9 to 33.7% mineralization after 100 days. These data indicate that primary biodegradation is an important fate process in soil, however rapid mineralization is not expected(7).

AQUATIC FATE: Based on a classification scheme(1), Koc values of 1,780 to 6,189(2,3), indicate that bifenazate is expected to adsorb to suspended solids and sediment(SRC). Volatilization from water surfaces is not expected(4) based upon an estimated Henry's Law constant of 7.9X10-9 atm-cu m/mole(SRC) derived from its vapor pressure, 7.5X10-8 mm Hg(5), and water solubility, 3.76 mg/L(6). Additionally, a pKa of 12.94(5) indicates bifenazate will exist almost entirely in the cation 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(7), an estimated BCF of 80(SRC), from a log Kow of 3.4(6), suggests the potential for bioconcentration in aquatic organisms is moderate(SRC). Utilizing the Modified Sturm test, 11.7% CO2 evolution was reached in 28 days therefore bifenazate is not considered readily biodegradable. Aerobic half-lives in water/sediment systems are reported as less than 6 hours to 7.3 hours with 18.9 to 33.7% mineralization after 100 days. These data indicate that primary biodegradation is an important fate process in water, however rapid mineralization is not expected(8).

ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), bifenazate, which has a vapor pressure of 7.5X10-8 mm Hg at 25 °C(2), is expected to exist solely in the particulate phase in the ambient atmosphere. Particulate-phase bifenazate may be removed from the air by wet and dry deposition(SRC). Bifenazate contains chromophores that absorb at wavelengths >290 nm(3) and, therefore, may be susceptible to direct photolysis by sunlight(SRC). Bifenazate undergoes direct photolysis in water with half-lives of 16 to 17 hours at 25 °C(4-6) and on soil with a half-life of less than 30 minutes(4,5).

Residues of bifenazate were detected at concentrations ranging from 0.25 to 5.49 ppm in commercial hop samples taken from Idaho, Oregon, and Washington in 2006 and 2007(1). In an FDA total diet study analyzing foods in 4 market basket studies from the fiscal year 2012, bifenazate was detected in 11 of 159 food items considered to be infant and toddler foods at a range of 0.0001 to 0.003 ppm and in 24 of 912 food items other than infant and toddler foods at a range of 0.0001 to 0.556 ppm(2). In an FDA total diet study analyzing foods in 4 market basket studies from the fiscal year 2013, bifenazate was detected in 25 of 1,070 food items at a range of 0.0004 to 0.024 ppm(3).

IDENTIFICATION AND USE: Bifenazate is a solid. It is used as acaricide/miticide (insecticide). HUMAN EXPOSURE AND TOXICITY: There are no data available. ANIMAL STUDIES: Bifenazate causes slight eye and skin irritant to rabbits. In dogs it caused myeloid hyperplasia and a dose-related decrease in numbers of erythrocytes and increased numbers of platelets and level of serum bilirubin at concentrations of 400 and 1000 ppm. The only developmental effects noted in rats were a slightly delayed balanopreputial separation for the males treated with concentrations of 80 and 200 ppm, and vaginal perforation for the females treated with 200 ppm. It was not mutagenic in S. typhimurium strains TA98, TA100, TA1535, and TA1537 and E. coli strain WP2 uvrA. There was no treatment-related increase in the percentage of cells with chromosomal aberrations in Chinese Hamster Ovary cells. Treatment with bifenazate did not result in an increase in the number of micronuclei in mice. ECOTOXICITY STUDIES: Bifenazate is categorized as slightly toxic to avian species on an acute oral basis (LD50=1032 mg/kg) and as moderately toxic to avian species on a subacute dietary basis (LC50=656-1862 ppm). Bifenazate is categorized as practically nontoxic to small mammals on an acute oral basis (LD50>5000 mg/kg). The available data indicate that bifenazate is categorized as highly toxic to freshwater fish (LC50=0.58-76 ppm) and aquatic invertebrates (LC50/EC50=0.50 ppm) on an acute basis.

/BIRDS and MAMMALS/ Bifenazate is categorized as slightly toxic to avian species on an acute oral basis (LD50=1032 mg/kg) and as moderately toxic to avian species on a subacute dietary basis (LC50=656-1862 ppm). Bifenazate is categorized as practically nontoxic to small mammals on an acute oral basis (LD50>5000 mg/kg).

/AQUATIC SPECIES/ The available data indicate that bifenazate is categorized as highly toxic to freshwater fish (LC50=0.58-76 ppm) and aquatic invertebrates (LC50/EC50=0.50 ppm) on an acute basis.

/OTHER TERRESTRIAL SPECIES/ This project assessed the potential hazards of different classical and novel acaricides against an important non-target and beneficial insect for the pollination of wild flowers and cultivated crops, the bumblebee Bombus terrestris (L). Twenty-three acaricides used commercially in the control of phytophagous mites (Acari) were tested in greenhouses and/or the open field. Side effects included acute mortality and also sublethal effects on nest reproduction. The different compounds were administered in the laboratory via three different worst-case field scenario routes of exposure: dermal contact and orally via the drinking of treated sugar water and via treated pollen. The compounds were tested at their respective maximum field recommended concentration (MFRC), and, when strong lethal effects were observed, a dose-response assay with a dilution series of the MFRC was undertaken to calculate LC(50) values. From the different acaricide classes, several chemistries caused high levels of acute toxicity in bumblebee workers, especially bifenthrin and abamectin which resulted in 100% mortality by contact. In addition, several acaricides tested were found to have a detrimental effect on drone production. For oral exposures via treated sugar water, the dose-response assay showed the LC(50) values for abamectin, bifenazate, bifenthrin and etoxazole to be 1/15 MFRC (1.17 mg AI/L), 1/10 MFRC (9.6 mg AI/L), 1/83 MFRC (0.36 mg AI/L) and 1/13 MFRC (4.4 mg AI/L) respectively, indicating that their use should be carefully evaluated. Overall, the results suggest that most of the acaricides tested are compatible with bumblebees, with the exceptions of abamectin, bifenazate, bifenthrin and etoxazole. However, the risks also depended on the type of treatment. As a result, the sugar water treatment seems to present the worst-case situation of exposure, indicating that this approach is suitable for determining the hazards of pesticides against bumblebees. Finally, it is suggested that future tier testing under more field-related conditions is required for a final decision of their risks.

/OTHER TERRESTRIAL SPECIES/ An analysis of the results indicate that bifenazate is categorized as moderately toxic to bees on an acute contact basis (LD50=7.5 ug/bee).

EPA has released the Interactive Chemical Safety for Sustainability (iCSS) Dashboard. The iCSS Dashboard provides an interactive tool to explore rapid, automated (or in vitro high-throughput) chemical screening data generated by the Toxicity Forecaster (ToxCast) project and the federal Toxicity Testing in the 21st century (Tox21) collaboration. /The title compound was tested by ToxCast and/or Tox21 assays/[USEPA; ICSS Dashboard Application; Available from, as of December 8, 2016: http://actor.epa.gov/dashboard/]

In column leaching experiments, bifenazate was reported to be immobile in silt and clay loams, and have low mobility in sandy loams(1). The Koc of bifenazate has been reported to range from 3,011 to 6,189 in soils(1). Bifenazate has a reported log Koc value of 3.25 (Koc = 1,780) from an adsorption/desorption screening test(2). According to a classification scheme(3), these Koc values suggest that bifenazate is expected to have low to no mobility in soil. The pKa of bifenazate is 12.94(4), indicating that this compound will exist almost entirely in cation form in the environment and cations generally adsorb more strongly to soils containing organic carbon and clay than their neutral counterparts(5).

Bifenazate's production may result in its release to the environment through various waste streams; its use as an acaricide(1) specifically as a selective miticide/insecticide for agricultural, residential, commercial, industrial, and institutional applications(2) will result in its direct release to the environment(SRC).

AEROBIC: Bifenazate exhbited 11.7% degradation, based on carbon dioxide production, after 28 days using a Modified Sturm test and is not considered readily biodegradable(1). Bifenazate has a half-life of less than 6 hours using 14C-labeled bifenazate in a water sediment system with sandy loam and clay loam, where 18.9 to 33.7% mineralization was reported after 100 days(1). An aerobic biodegradation half-life in soil of approximately 7 hours is also reported(2-4). This suggests that bifenazate may biodegrade rapidly in soil and water under certain environmental conditions(SRC). The bifenazate degradation product D1989 has an aerobic soil metabolism half-life of 24.4 days(4).

ANAEROBIC: The anaerobic biodegradation half-life of bifenazate in soil was reported as 77.9 days(1). Anaerobic degradation products include (1,1'-Biphenyl)-4-ol (A1530) and desmethyl (D3598)(2).

Tolerances are established for residues of bifenazate (1-methylethyl 2-(4-methoxy[1,1'-biphenyl]-3-yl)hydrazinecarboxylate) including its metabolites and degradates, in or on the commodities listed in the following table. Compliance with the tolerance levels specified are to be determined by measuring only the sum of bifenazate and its metabolite, diazinecarboxylic acid, 2-(4-methoxy-[1,1'-biphenyl]-3-yl), 1-methylethyl ester, (calculated as the stoichiometric equivalent of bifenazate) in or on the following food commodities:[Table#6594]

Tolerances are established for residues of bifenazate (1-methylethyl 2-(4-methoxy[1,1'-biphenyl]-3-yl) hydrazinecarboxylate) including its metabolites and degradates, in or on the commodities listed in the following table. Compliance with the tolerance levels specified are to be determined by measuring only the sum of bifenazate and its metabolites diazinecarboxylic acid, 2-(4-methoxy-[1,1'-biphenyl]-3-yl), 1-methylethyl ester; 1,1'-biphenyl, 4-ol; and 1,1'-biphenyl, 4-oxysulfonic acid (calculated as the stoichiometric equivalent of bifenazate) in or on the following food commodities:[Table#6595]

Tolerances with regional registration, as defined in section 180.1(l), are established for residues of bifenazate (1-methylethyl 2-(4-methoxy[1,1'-biphenyl]-3-yl)hydrazinecarboxylate) including its metabolites and degradates, in or on the commodities listed in the following table. Compliance with the tolerance levels specified are to be determined by measuring only the sum of bifenazate and its metabolite, diazinecarboxylic acid, 2-(4-methoxy-[1,1'-biphenyl]-3-yl), 1-methylethyl ester, (calculated as the stoichiometric equivalent of bifenazate) in or on the following food commodities:[Table#6596]

New Pesticide Fact Sheet: Name of Chemical: Bifenazate; Year of Initial Registration: 1999. Pesticide Type: Acaricide.

Used as a selective miticide for the control of a variety of mite pests on ornamental plants and fruit trees in greenhouses, nurseries, and landscapes; [HSDB]

Farming (Pesticides) [Category: Industry]

For bifenazate (USEPA/OPP Pesticide Code: 000586) ACTIVE products with label matches. /SRP: Registered for use in the U.S. but approved pesticide uses may change periodically and so federal, state and local authorities must be consulted for currently approved uses./

Acaricide/miticide, insecticide.

Insecticide

This is a man-made compound that is used as a pesticide.

Bifenazate can be prepared by Lewis acid-catalyzed electrophilic aromatic substitution of 4-methoxybiphenyl with diisopropyl azodicarboxylate yielding hydrazine dicarboxylate, which is then transformed into the compound desired by a decarboxylation reaction.

Preparation: M. A. Dekeyser, P. T. McDonald, World Intellectual Property Organization patent 9310083; eidem, United States of America patent 5367093 (1993, 1994 both to Uniroyal).

Bifenazate Technical (Macdermid Agricultural Solutions, Inc): Active ingredient: Bifenazate 96.7%.

Floramite (Macdermid Agricultural Solutions, Inc): Active ingredient: Bifenazate 50.0%.

Acramite-50WS (Macdermid Agricultural Solutions, Inc): Active ingredient: Bifenazate 50.0%.

Floramite SC (Macdermid Agricultural Solutions, Inc): Active ingredient: Bifenazate 22.6%.

For more Formulations/Preparations (Complete) data for Bifenazate (14 total), please visit the HSDB record page.

Acaricides, Insecticides

Environmental transformation -> Pesticides (parent, predecessor)