Isoxaben

Pesticide -> EPA IRIS

Herbicides

Active substance -> EU Pesticides database: Approved

Pesticides -> Herbicides, Other

Herbicides

Pesticide (Isoxaben) -> USDA PDB

log Kow = 3.94 at 25 °C

3.0

White crystalline solid

Light tan granule

Slight solubility in organic solvents (methanol, ethyl acetate, dichloromethane, acetonitrile)

At 25 °C, methanol and ethyl acetate 50-100 mg/mL; acetonitrile 30-35 mg/mL; toluene 4-5mg/mL; hexane 0.07-0.08 mg/mL; and water 0.001-0.002 mg/mL

In water, 1.42 mg/L at pH 7 and 20 °C

H413: May cause long lasting harmful effects to aquatic life [Hazardous to the aquatic environment, long-term hazard]

P273, and P501 (click each P-code to see the statement)

Warning

H400 (64%): Very toxic to aquatic life [Warning Hazardous to the aquatic environment, acute hazard]

P273, P391, and P501 (click each P-code to see the statement)

Aggregated GHS information provided per 86 reports by companies from 3 notifications to the ECHA C&L Inventory. Each notification may be associated with multiple companies.

Regulation (EC) No 396/2005 (amended)

Isoxaben is listed in the dataset of EPA Human Health Benchmarks for Pesticides under the Safe Drinking Water Act (40 eCFR 141)

2011/32/EU, Reg. (EU) 2020/2007, Reg. (EU) 2024/1206, Reg. (EU) No 2018/1266, Reg. (EU) No 540/2011

Status: Active Update: 15-12-2008 https://echa.europa.eu/registration-dossier/-/registered-dossier/4864

Isoxaben: Does not have an individual approval but may be used as a component in a product covered by a group standard. It is not approved for use as a chemical in its own right.

The New Jersey Worker and Community Right to Know Act requires public and private employers to provide information about hazardous substances at their workplaces. (N.J.S.A. 34:5A-1 et. seq.)

... No longer have registered food uses, and EPA has begun the process of proposing to revoke the tolerances associated with these pesticides. Isoxaben is included on this list.

New Active Ingredients ... includes pesticide active ingredients initially registered after November 1, 1984, that currently have active product registrations. By law, these newer pesticides are not subject to the reregistration program. They must, however, meet the new safety standard of the FQPA, and will be reviewed on a 15-year cycle under the registration review program. ... Active Ingredient Number: 125851; Type of Pesticide: conventional-herbicide; Use Site: food use, ornamentals, turf use; Year: 1989.

Aquatic Chronic 4 (100%)

Aquatic Acute 1 (64%)

Hazardous to the aquatic environment (chronic) - category 4

Skin corrosion/irritation - Category 2

Carcinogens

Aquatic Chronic 4

Store in a cool, dry, well ventilated, secure area out of reach of children and animals.

Safe Storage of Pesticides. Always store pesticides in their original containers, complete with labels that list ingredients, directions for use, and first aid steps in case of accidental poisoning. Never store pesticides in cabinets with or near food, animal feed, or medical supplies. Do not store pesticides in places where flooding is possible or in places where they might spill or leak into wells, drains, ground water, or surface water.

If a spill occurs, clean it up promptly. Don't wash it away. Instead, sprinkle the spill with sawdust, vermiculite, or kitty litter. Sweep it into a plastic garbage bag, and dispose of it as directed on the pesticide product label.

After Applying a Pesticide, Indoors or Outdoors. To remove pesticide residues, use a bucket to rinse tools or equipment three times, including any containers or utensils that you used when mixing the pesticide. Then pour the rinsewater into the pesticide sprayer and reuse the solution by applying it according to the pesticide product label directions. After applying any pesticide wash your hands and any other parts of your body that may have come in contact with the pesticide..To prevent tracking pesticides inside, remove or rinse your boots or shoes before entering your home. Wash any clothes that have been exposed to a lot of pesticide separately from your regular wash.

Safe Disposal of Pesticides. The best way to dispose of small amounts of excess pesticides is to use them - apply them - according to the directions on the label. If you cannot use them, ask your neighbors whether they have a similar pest control problem and can use them. If all of the remaining pesticide cannot be properly used, check with your local solid waste management authority, environmental agency, or health department to find out whether your community has a household hazardous waste collection program or a similar program for getting rid of unwanted, leftover pesticides. These authorities can also inform you of any local requirements for pesticide waste disposal.

Safe Disposal of Pesticides. An empty pesticide container can be as hazardous as a full one because of residues left inside. Never reuse such a container. When empty, a pesticide container should be rinsed carefully three times and the rinsewater thoroughly drained back onto the sprayer or the container previously used to mix the pesticide. Use the rinsewater as a pesticide, following label directions. Replace the cap or closure securely. Dispose of the container according to label instructions. Do not puncture or burn a pressurized container like an aerosol - it could explode. Do cut or puncture other empty pesticide containers made of metal or plastic to prevent someone from reusing them. Wrap the empty container and put it in the trash after you have rinsed it.

SRP: The most favorable course of action is to use an alternative chemical product with less inherent propensity for occupational exposure 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, aquatic, and plant life; and conformance with environmental and public health regulations.

/For applying the product/ wear the items of protective clothing the label requires: for example, non-absorbent gloves (not leather or fabric), rubber footwear (not canvas or leather), a hat, goggles, or a dust-mist filter. If no specific clothing is listed, gloves, long-sleeved shirts and long pants, and closed shoes are recommended. You can buy protective clothing and equipment at hardware stores or building supply stores.

Outdoor Applications. Never apply pesticides outdoors on a windy day (winds higher than 10 mph). Position yourself so that a light breeze does not blow pesticide spray or dust into your face.

SRP: Contaminated protective clothing should be segregated in such a manner so that there is no direct personal contact by personnel who handle, dispose, or clean the clothing. Quality assurance to ascertain the completeness of the cleaning procedures should be implemented before the decontaminated protective clothing is returned for reuse by the workers. Contaminated clothing should not be taken home at end of shift, but should remain at employee's place of work for cleaning.

LC50 Anas platyrhynchos (Mallard duck, 2 days old) dietary >5000 ppm/8 days

LD50 Apis mellifera (Honey bee) topical >101.7 ug/bee

LD50 Colinus virginianus (Bobwhite quail) oral >2000 mg/kg

LC50 Colinus virginianus (Northern bobwhite, 12 days old) dietary >5000 ppm/8 days

For more Ecotoxicity Values (Complete) data for ISOXABEN (12 total), please visit the HSDB record page.

TERRESTRIAL FATE: Based on a classification scheme(1), an estimated Koc value of 3,300(SRC), determined from a log Kow of 3.94(2) and a regression-derived equation(3), indicates that isoxaben is expected to have slight mobility in soil(SRC). Volatilization of isoxaben from moist soil surfaces is not expected to be an important fate process(SRC) given a Henry's Law constant of 1.27X10-9 atm-cu m/mole(2). Isoxaben is not expected to volatilize from dry soil surfaces(SRC) based upon its vapor pressure(2). Reported half-lives of isoxaben in soil range from 2.07 to 6.6 months with the largest half-lives noted in soils treated with various fertilizers such as green manure, cow manure and pig slurry: 4.03, 4.75 and 6.6 months, respectively(4). The main biodegradation metabolite of isoxaben was demethoxyisoxaben(5). When applied to soil at rates of 0.56, 0.84, and 1.12 kg/hectare, 50% of isoxaben remained after 3 months, 6 months, and 3 months, respectively(6).

TERRESTRIAL FATE: Isoxaben's half-life in soils that were previously treated with the insecticide were about half of the that of soil not previously treated with the insecticide. Of 5 soils from pear tree orchards in Europe used in a field study, only 2 had previously been treated with isoxaben. Isoxaben half-life in the 3 soil samples that had been treated with other pesticides ranged from 2.7-6.1 months(1). Isoxaben has been found in the runoff water from containerized plant production facilities 4 days after application. The other pesticides in this study, trifluralin, chlorpyrifos and thiophanate methyl were primarily only detected on the day of application(2).

TERRESTRIAL FATE: In winter wheat fields treated with isoxaben from 1990-1991 and 1991-1992 the main metabolite detected was demethoxyisoxaben and appeared in the soil within 34-41 days after treament. It was found in the soil after 282 days(1). The second main isoxaben metabolite found in the soil was 5-aminoisoxazole which appeared within 83 days of treatment. The products did not accumulate in the soil. Isoxaben in concentrations ranging from 9-16% of the concentration found on day 3 was still found in the soil after 282 days after treatment(1).

AQUATIC FATE: Based on a classification scheme(1), an estimated Koc value of 3,300(SRC), determined from a log Kow of 3.94(2) and a regression-derived equation(3), indicates that isoxaben is expected to adsorb to suspended solids and sediment(SRC). Volatilization from water surfaces is not expected(3) based upon a Henry's Law constant of 1.27X10-9 atm-cu m/mole(2). According to a classification scheme(4), an estimated BCF of 215(SRC), from its log Kow(2) and a regression-derived equation(5), suggests the potential for bioconcentration in aquatic organisms is high(SRC). Biodegradation data on isoxaben in water were not located; however based on data from soil studies(6-8), isoxaben may biodegrade slowly in aquatic environments(SRC).

ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), isoxaben, which has a vapor pressure of 4.13X10-9 mm Hg at 25 °C(2), is expected to exist solely in the particulate phase in the ambient atmosphere. Particulate-phase isoxaben may be removed from the air by wet and dry deposition(SRC). Aqueous solution of isoxaben have be shown to be susceptible to photodegradation(2).

Isoxaben has been found in the runoff water from containerized plant production facilities 4 days after application. The other pesticides in this study, trifluralin, chlorpyrifos and thiophanate methyl, were primarily only detected on the day of application(1).

Isoxaben

Cardiovascular

5 x 10 ^-2 mg/kg-day

The Koc of isoxaben is estimated as 3,300(SRC), using a log Kow of 3.94(1) and a regression-derived equation(2). According to a classification scheme(3), this estimated Koc value suggests that isoxaben is expected to have slight mobility in soil.

AEROBIC: Reported half-lives of isoxaben in soil range from 2.07 to 6.6 months with the largest half-lives noted in soils treated with various fertilizers such as green manure, cow manure and pig slurry: 4.03, 4.75 and 6.6 months, respectively(1). The main biodegradation metabolite of isoxaben was demethoxyisoxaben(2). When applied to soil at rates of 0.56, 0.84, and 1.12 kg/hectare, 50% of isoxaben remained after 3 months, 6 months, and 3 months, respectively(3).

An estimated BCF of 215 was calculated for isoxaben(SRC), using a log Kow of 3.94(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), provided the compound is not metabolized by the organism(SRC).

The Henry's Law constant for isoxaben is 1.27X10-9 atm-cu m/mole(1). This Henry's Law constant indicates that isoxaben is expected to be essentially nonvolatile from moist soil and water surfaces(SRC). Isoxaben is not expected to volatilize from dry soil surfaces(SRC) based upon its vapor pressure(1).

... No longer have registered food uses, and EPA has begun the process of proposing to revoke the tolerances associated with these pesticides. Isoxaben is included on this list.

New Active Ingredients ... includes pesticide active ingredients initially registered after November 1, 1984, that currently have active product registrations. By law, these newer pesticides are not subject to the reregistration program. They must, however, meet the new safety standard of the FQPA, and will be reviewed on a 15-year cycle under the registration review program. ... Active Ingredient Number: 125851; Type of Pesticide: conventional-herbicide; Use Site: food use, ornamentals, turf use; Year: 1989.

In rats, following oral administration, 90% is excreted in the feces within 48 hours; about 10% of the absorbed isoxaben undergoes conversion into about 15-20 metabolites, which are excreted in the urine. There is no accumulation of either parent or metabolites in cell tissue.

Used as selective pre-emergence herbicide for control of broad-leaved weeds and annual grasses; [Merck Index] Used for cereals, turf, and ornamentals; [HSDB]

Farming (Pesticides) [Category: Industry]

For isoxaben (USEPA/OPP Pesticide Code: 125851) 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./

Herbicide; For annual broadleaf weeds in turf, ornamentals.

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

Dry flowable, suspension concentrate.

Discontinued products: Snapshot

Trade Names: Flexidor, El 107.