Diflubenzuron

Wear self contained breathing apparatus for fire fighting if necessary.

Fire Extinguishing Media: Water spray, dry chemical.

Use personal protective equipment. Avoid dust formation. Avoid breathing vapors, mist or gas. Ensure adequate ventilation. Evacuate personnel to safe areas. Avoid breathing dust.

Collect spill to prevent product from entering sewage system.

SRP: The most favorable course of action is to use an alternative chemical product with less inherent propensity for occupational harm/injury/toxicity or environmental contamination. 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 soil or water; effects on animal and plant life; and conformance with environmental and public health regulations.

Avoid contact with skin and eyes. Avoid formation of dust and aerosols. Provide appropriate exhaust ventilation at places where dust is formed. Normal measures for preventive fire protection.

SRP: The scientific literature for the use of contact lenses by industrial workers is inconsistent. The benefits or detrimental effects of wearing contact lenses depend not only upon the substance, but also on factors including the form of the substance, characteristics and duration of the exposure, the uses of other eye protection equipment, and the hygiene of the lenses. However, there may be individual substances whose irritating or corrosive properties are such that the wearing of contact lenses would be harmful to the eye. In those specific cases, contact lenses should not be worn. In any event, the usual eye protection equipment should be worn even when contact lenses are in place.

Tolerances are established for residues of diflubenzuron, including its metabolites and degradates, in or on the commodities in the table below. Compliance with the tolerance levels specified below is to be determined by measuring only diflubenzuron (N-[[(4-chlorophenyl)amino]carbonyl]-2,6-difluorobenzamide).[Table#6112]

Tolerances are established for residues of the insecticide diflubenzuron (N-[[(4-chlorophenyl)amino]carbonyl]-2,6-difluorobenzamide), in or on the commodities in the table below. Compliance with the tolerance levels specified below is to be determined by measuring only the sum of diflubenzuron (N-[[(4-chlorophenyl)amino]carbonyl]-2,6-difluorobenzamide), 4-chlorophenylyurea and 4-chloroaniline, calculated as the stoichiometric equivalent of diflubenzuron, in or on the commodity.[Table#6113]

Time-limited tolerances are established for residues of the insecticide diflubenzuron (N-[[(4-chlorophenyl)amino]carbonyl]-2,6-difluorobenzamide) and its metabolites, in connection with use of the pesticide under section 18 emergency exemptions granted by EPA. Compliance with the tolerance levels specified below is to be determined by measuring only the sum of diflubenzuron (N-[[(4-chlorophenyl)amino]carbonyl]-2,6-difluorobenzamide), 4-chlorophenylyurea and 4-chloroaniline, calculated as the stoichiometric equivalent of diflubenzuron, in or on the commodity. The tolerances are specified in the following table, and will expire and are revoked on the dates specified.[Table#6114]

Excerpt from ERG Guide 171 [Substances (Low to Moderate Hazard)]:

Safety glasses with side-shields conforming to EN166 Use equipment for eye protection tested and approved under appropriate government standards such as NIOSH (US) or EN 166(EU).

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).

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.

Handle with gloves. 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.

Although the toxins of Bacillus thuringiensis Berliner (Bt) are frequently used to control lepidopteran pests, the tolerance or resistance of some lepidopteran moth strains may limit Bt applications. In this study, insecticidal cocktails consisting of sublethal doses of Cry1Ab toxin and additive compounds were tested for their suppressive effect on larval relative growth rate (RGR) in Ephestia kuehniella Zeller under laboratory conditions. In the first step, the suppressive effect of diflubenzuron, soybean trypsin inhibitor (STI) and chitinase on RGR was confirmed. In the second step, these compounds were incorporated into a mixture of crushed kernels of Bt maize hybrid MON 810-YieldGard and its isoline with concentrations of Cry1Ab toxin ranging from 0.011 to 0.091 ug/g diet. An additive effect on the suppression of larval RGR in E. kuehniella was found in a combination of diflubenzuron, STI and STI + chitinase as secondary compounds in insecticidal cocktails. Chitinase showed no additive effect on RGR. The highest suppression level was found in cocktails with STI + chitinase as a secondary compound. It is hypothesized that the protease inhibitor (STI) protects both chitinase and Cry1Ab proteins from endogenous proteases in the larval midgut and prolongs their insecticidal activities. The possible application of insecticidal cocktails in the control of E. kuehniella is discussed.

Aedes aegypti mosquito is one of the most notorious vectors of dangerous diseases like dengue hemorrhagic fever and chikangunya. One method of control of the vectors is by the use of semiochemicals or pheromones. The pheromone n-heneicosane (C21) has been proved to be effective in attracting the female Aedes aegypti to lay eggs in the treated water and the growth of the larva is controlled by insect growth regulator diflubenzuron (DB). This study was planned to assess the safety of C21 alone and the combination with DB. Acute toxicity tests were carried out using two doses, viz., 1600 and 3200 mg/kg and two routes of exposure oral and intra-peritoneal. Dermal toxicity test was carried out in both male and female rats at the dose of 3200 mg/kg. Primary skin irritation test was carried out in rabbits. Sub-acute (90 days) dermal toxicity studies in male and female rats at the dose of 1 and 2 mg/kg via the per-cutaneous route were also studied. Sub-acute (90 days) toxicity test through the oral route was carried out, at doses 125, 250 and 500 mg/kg in male and female rats. The calculated LD50 by ip route and dermal route was more than 5 g/kg in mouse and rats of both the sexes. In the primary skin irritation test no significant changes were noted. In the sub-acute toxicity studies even 500 mg/kg dose was not able to produce toxic response in rats when they were dosed daily for 90 days. The established no observed adverse effect level (NOAEL) was more than 500 mg/kg.

One of the metabolites of diflubenzuron, PCA, has severe health effects. It is associated with cancer of the spleen and liver and osteosarcomas in male rats. Another metabolite of diflubenzuron also has carcinogenic potential and the same carcinogenic potency as PCA.

LC50; Species: Agelaius phoeniceus (Red-Winged Blackbird) adult; oral via capsule 3763 mg/kg (95% confidence interval: 3400-4000 ug/L)

LC50; Species: Colinus virginianus (Northern Bobwhite Quail) age 14 days; chemical incorporated into food >4640 ppm for 8 days

LC50; Species: Colinus virginianus (Northern Bobwhite Quail) age 10-15 days; chemical incorporated into food >20000 ppm for 8 days

LC50; Species: Anas platyrhynchos (Mallard Duck) age 14 days; chemical incorporated into food >4640 ppm for 8 days

For more Ecotoxicity Values (Complete) data for DIFLUBENZURON (45 total), please visit the HSDB record page.

TERRESTRIAL FATE: Based on a classification scheme(1), Koc values of 6,790 and 10,600(2) indicate that diflubenzuron is expected to be immobile in soil(SRC). Volatilization of diflubenzuron from moist soil surfaces is not expected to be an important fate process(SRC) given an estimated Henry's Law constant of 4.6X10-9 atm-cu m/mole(SRC), calculated from its vapor pressure of 9X10-10 mm Hg(3) and water solubility of 0.08 mg/L(3). Diflubenzuron is not expected to volatilize from dry soil surfaces(SRC) based upon its vapor pressure. In photodegradation tests on soil surfaces, diflubenzuron has a reported half-life of 11.3 days(2). Microorganisms play a major role in the disappearance of diflubenzuron from soil(4,5). Field dissipation half-lives are reported to range from 2 to 35 days(2). Bare ground dissipation half-lives range from 5.8-13.2 days with half-lives as high as 68.2-78 days in citrus and apple orchards(5). An apparent half-life of 30 days was observed in a forestry study(5).

AQUATIC FATE: Based on a classification scheme(1), a Koc values of 6,790 and 10,600(2) indicate that diflubenzuron is expected to adsorb to suspended solids and sediment(SRC). Volatilization from water surfaces is not expected(3) based upon an estimated Henry's Law constant of 4.6X10-9 atm-cu m/mole(SRC), derived from its vapor pressure of 9X10-10 mm Hg(4) and water solubility of 0.08 mg/L(4). According to a classification scheme(5), bluegill sunfish BCF values of 34-200 for fillet and 78-360 for whole fish(6) suggest the potential for bioconcentration in aquatic organisms is moderate to high(SRC). The hydrolysis half-life of diflubenzuron at pH 5 and pH 7 is >180 days at 25 °C(7); at pH 9, the hydrolysis half-life is 32.5 days(7). The direct photolysis half-life of diflubenzuron in aqueous solution under natural sunlight conditions at 40 deg N latitude is reported to be 80 days(7). Much faster photodegradation half-lives have been observered using river water(8) suggesting diflubenzuron may be susceptible to photo-sensitized photolysis(SRC). Biodegradation half-lives averaged between 14 and 32 days in screening tests using marine-sediment and marine-water(9), suggesting biodegradation is an important fate process in water(SRC). When incubated under flooded anaerobic conditions with a silt loam soil, diflubenzuron had a half-life of 34 days at 24 °C(6).

ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), diflubenzuron, which has a vapor pressure of 9X10-10 mm Hg at 25 °C(2) is expected to exist solely in the particulate phase in the ambient atmosphere. Particulate-phase diflubenzuron may be removed from the air by wet and dry deposition(SRC). Diflubenzuron has been shown to degrade through direct photolysis in sunlight(3,4) suggesting that photolysis may occur in the atmosphere(SRC).

Dislodgeable residues of diflubenzuron were identified 1 and 29 days post-application (March-April, 1978) at respective concentrations of 0.40 and 0.32 ppm on the fruit in an orange grove in Florida(1). Dislodgeable residues of diflubenzuron were identified 1 and 29 days post-application (July-August, 1978) at respective concentrations of 0.18 and 0.07 ppm on the fruit in an orange grove in Florida(1). In a monitoring study in Valencia Spain where 150 orange fruit samples were collected between Sept 1998 and June 1999, diflubenzuron was detected in 20 samples and concentrations ranging from 0.003-1.8 mg/kg(2).

/BIRDS and MAMMALS/ Toxicity to mammals and birds is low (LD50 values in the range of 4500 to 10,000 mg/kg).

/BIRDS and MAMMALS/ A 5-day dietary study on the mallard duck and bobwhite quail with levels of up to 4640 mg/kg did not reveal any observable signs of toxicity. Small songbirds in the forest ecosystem were not affected after aerial application of diflubenzuron at 350 g/ha. Small mammal species in a forest did not show any reductions in numbers after application of diflubenzuron at 67 g/ha.

/AQUATIC SPECIES/ Increasing use of the chitin synthesis inhibitor diflubenzuron against the ectoparasitic salmon louse Lepeophtheirus salmonis in marine aquaculture has raised concerns over its environmental impacts. This study evaluated how diflubenzuron affects Atlantic cod Gadus morhua, a fish species often found near Atlantic salmon Salmo salar farms, focusing on uptake kinetics and hepatic transcriptional responses. Two experiments were conducted, one time-series trial in which the fish were given a daily dose (3 mg/kg fish) of diflubenzuron for 14 d followed by a 3 wk depuration period, and one dose-response trial with increasing concentrations (3, 10 and 50 mg/kg fish). The highest diflubenzuron concentrations were found in the liver at Day 15. No detectable levels of diflubenzuron were found in liver or muscle 3 wk after the end of the treatment. At the molecular level, small effects of diflubenzuron treatment on gene transcription were observed. In the time-series experiment, the strongest effects were seen at Day 8, with 2 transcripts being upregulated (bclx2 and cpt1a) and 8 transcripts being downregulated (gstp1, gstm1, gstt1, ugt1a, nat2, cat, p53 and slc16a9a). Five transcripts (cyp3a, cpt1a, ptgs2, elovl5 and mapk1) responded significantly to diflubenzuron exposure in the dose-response experiment. This study shows that diflubenzuron can be taken up by Atlantic cod, that it is rapidly cleared from the body and that when present this pharmaceutical causes only small effects on the expression of genes involved in detoxification pathways. Taken together, our data suggest that accumulated diflubenzuron at the levels studied would have a relatively small effect on wild Atlantic cod.

/AQUATIC SPECIES/ The effects of diflubenzuron (DFB), an insecticide to control ectoparasites in fish farms, on muscle acetylcholinesterase (AChE), detoxifying and antioxidant enzymes, hematological and physiological parameters, and liver histopathology were evaluated in Prochilodus lineatus after 6, 24 and 96 hr of exposure to 25 mg/L of DFB. The insecticide caused a reduction in the number of erythrocytes and hemoglobin content after 96 hr exposure, probably due to hemolysis. Hyperglycemic response indicated energy mobilization, and may have contributed to the increase in osmolarity after 96 hr exposure to DFB. The induction of glutathione-S-transferase (GST) and catalase activities in liver pointed to the activation of xenobiotic metabolic pathways and antioxidant defenses. The decrease in muscle AChE at all experimental times showed that DFB is an AChE inhibitor. In addition, DFB induced hepatic alterations that might impair normal liver functions. These results show that DFB can cause health disorders in fish and further studies are required to better define its safe use in aquaculture.

During the use of diflubenzuron in the suppression of insect defoliators, residues were detected 21 days after application at a concentration of 0.18 ppm on foliage at Sleepy Creek Public Hunting and Fishing Area, Morgan County, WV(1). Dislodgeable residues of diflubenzuron were identified 1 and 29 days postapplication (March-April, 1978) at respective concentrations of 0.17 and 0.13 ppm on the leaves in an orange grove in Florida(2). Dislodgeable residues of diflubenzuron were identified 1 and 29 days postapplication (July-August, 1978) at respective concentrations of 0.10 and 0.05 ppm on the leaves in an orange grove in Florida(2). Diflubenzuron was detected on leaves in a Pennsylvania forest that was recently sprayed at concentrations of 7.2-235.22 ng/sq cm on the upper canopy and 5.46-131.44 ng/sq cm on leaves of the lower canopy(3). After aerial spraying of the Appalachian forest, West Virginia in 1991, diflubenzuron was detected in foliage of trees at 2.91-75 ng/sq cm (upper canopy) and 1.92-24.9 ng/sq cm (lower canopy)(4). These concentrations decreased roughly 40-47% after a rain event(4).

Tolerances are established for residues of diflubenzuron, including its metabolites and degradates, in or on the commodities in the table below. Compliance with the tolerance levels specified below is to be determined by measuring only diflubenzuron (N-[[(4-chlorophenyl)amino]carbonyl]-2,6-difluorobenzamide).[Table#6115]

Tolerances are established for residues of the insecticide diflubenzuron (N-[[(4-chlorophenyl)amino]carbonyl]-2,6-difluorobenzamide), in or on the commodities in the table below. Compliance with the tolerance levels specified below is to be determined by measuring only the sum of diflubenzuron (N-[[(4-chlorophenyl)amino]carbonyl]-2,6-difluorobenzamide), 4-chlorophenylyurea and 4-chloroaniline, calculated as the stoichiometric equivalent of diflubenzuron, in or on the commodity.[Table#6116]

Time-limited tolerances are established for residues of the insecticide diflubenzuron (N-[[(4-chlorophenyl)amino]carbonyl]-2,6-difluorobenzamide) and its metabolites, in connection with use of the pesticide under section 18 emergency exemptions granted by EPA. Compliance with the tolerance levels specified below is to be determined by measuring only the sum of diflubenzuron (N-[[(4-chlorophenyl)amino]carbonyl]-2,6-difluorobenzamide), 4-chlorophenylyurea and 4-chloroaniline, calculated as the stoichiometric equivalent of diflubenzuron, in or on the commodity. The tolerances are specified in the following table, and will expire and are revoked on the dates specified.[Table#6117]

Based on the reviews of the generic data for the active ingredient diflubenzuron, the Agency has sufficient information on the health effects of diflubenzuron and on its potential for causing adverse effects in fish and wildlife and the environment. The Agency has determined that diflubenzuron products, labeled and used as specified in this Reregistration Eligibility Decision, will not pose unreasonable risks or adverse effects to humans or the environment. ... Therefore, the Agency concludes that products containing diflubenzuron, once labels have been amended to reflect the risk mitigation measures outlined in this RED, are eligible for reregistration.

As the federal pesticide law FIFRA directs, EPA is conducting a comprehensive review of older pesticides to consider their health and environmental effects and make decisions about their continued use. Under this pesticide reregistration program, EPA examines newer health and safety data for pesticide active ingredients initially registered before November 1, 1984, and determines whether the use of the pesticide does not pose unreasonable risk in accordance to newer safety standards, such as those described in the Food Quality Protection Act of 1996. Diflubenzuron is found on List A, which contains most pesticides that are used on foods and, hence, have a high potential for human exposure. List A consists of the 194 chemical cases (or 350 individual active ingredients) for which EPA issued registration standards prior to FIFRA '88. Case No: 0144; Pesticide type: insecticide (larvicide, avicide); Registration Standard Date: 09/10/85; Case Status: RED Approved 05/97; OPP has made a decision that some/all uses of the pesticide are eligible for reregistration, as reflected in a Reregistration Eligibility Decision (RED) document.; Active ingredient (AI): Diflubenzuron; Data Call-in (DCI) Date(s): 09/28/91, 03/09/92; AI Status: OPP has completed a Reregistration Eligibility Decision (RED) document for the case/AI.

Used as insecticide; Inhibits chitin deposition in insect cuticle; [Merck Index] Used as insecticide (larvicide); inhibits molting of larvae of mosquitoes, houseflies, stable flies, and black flies by interfering with chitin synthesis; [HSDB] Used to control leaf-feeding larvae and leaf miners in forestry, top fruit, citrus, and field crops; [INCHEM] Used mainly on cattle, citrus, cotton, mushrooms, ornamentals, standing water, trees, and to control mosquitoes and gypsy moths; [Reference #1]

Farming (Pesticides) [Category: Industry]

For diflubenzuron (USEPA/OPP Pesticide Code: 108201) 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/Insecticide (insect growth regulator)

Restricted Use Pesticide for sale and use by certified pesticide applicators or person under their supervision due to toxicity to aquatic invertebrates.

For control of a wide range of leaf-eating insects in forestry, woody ornamentals and fruit. Controls certain major pests in cotton, soya beans, citrus, tea, vegetables and mushrooms. Also controls larvae of flies, mosquitoes, grasshoppers and migratory locusts. Used as an ectoparasiticide on sheep for control of lice, fleas and blowfly larvae. Due to its selectivity and rapid degradation in soil and water, diflubenzuron has no or only a slight effect on the natural enemies of various harmful insect species. These properties make it suitable for inclusion in integrated control programmes.

2,6-Difluorobenzamide is reacted with 4-chlorophenyl isocyanate in an organic solvent medium. The product isolated from the reaction mixture has a mp of 210-230 °C.

Preparation: K. Wellinga, R. Mulder, German patent 2123236; eidem, United States of America patent 3748356 (1971, 1973 both to Philips).

Granular, oil dispersible concentrate, suspension concentrate, wettable powder, flowable.

Premix Partners: Methomyl.

Dimilin WP-25, wettable powder (250 g ai/kg); Dimilin G1 and G4 granules (10 or 40 g/kg); Dimilin ODC-45, ultra-low volume liquid, hot fogging concentrate (450 g/l).

F793 Insecticide (Farnam Companies, Inc.): Active ingredient: Diflubenzuron 0.24%.

For more Formulations/Preparations (Complete) data for DIFLUBENZURON (41 total), please visit the HSDB record page.

Veterinary Drug -> INSECTICIDE; Veterinary Drug -> -> JECFA Functional Classes

Environmental transformation -> Pesticides (parent, predecessor)

Insecticides

INSECTICIDES

Benzamide, N-[[(4-chlorophenyl)amino]carbonyl]-2,6-difluoro-: ACTIVE

The WHO Recommended Classification of Pesticides by Hazard identifies diflubenzuron (technical grade) as Class III: slightly hazardous; Main Use: larvicide.