Oxadiazon

345.22100

345.22

243-215-7

C6U0E0YTP6

3077|2588

DTXSID3024239

White crystals|Colorless crystals

2934999010

57.26000

4.21700

Oxydiazon is a crystalline solid. Used as an herbicide.

1 x 10^-6 g/cm³

90 °C

417ºC at 760 mmHg

206ºC

1.569

In water, 0.7 mg/l @ 24 deg C

0-6ºC

3.65E-07mmHg at 25°C

LD50 orally in rats, bobwhite quail, mallard duck: 8000, 6000, 1000 mg/kg (Lim)

Odorless

182.17 Ų [M+H]+ [CCS Type: TW]

Dust may form an explosive mixture in air.

Azo, Diazo, Azido, Hydrazine, and Azide Compounds

Explosive

OXYDIAZON is a diazo compound. Azo, diazo, azido compounds can detonate. This applies in particular to organic azides that have been sensitized by the addition of metal salts or strong acids. Toxic gases are formed by mixing materials of this class with acids, aldehydes, amides, carbamates, cyanides, inorganic fluorides, halogenated organics, isocyanates, ketones, metals, nitrides, peroxides, phenols, epoxides, acyl halides, and strong oxidizing or reducing agents. Flammable gases are formed by mixing materials in this group with alkali metals. Explosive combination can occur with strong oxidizing agents, metal salts, peroxides, and sulfides.

UN3077 9/PG 3

2

R50/53

S60-S61

RO0874000

N

Stable under normal storage conditions.

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.

Excerpt from ERG Guide 171 [Substances (Low to Moderate Hazard)]: Some may burn but none ignite readily. Containers may explode when heated. Some may be transported hot. For UN3508, be aware of possible short circuiting as this product is transported in a charged state. (ERG, 2016)

|Warning|H400: Very toxic to aquatic life [Warning Hazardous to the aquatic environment, acute hazard]|P273, P391, and P501|H400 (100%): Very toxic to aquatic life [Warning Hazardous to the aquatic environment, acute hazard]|Aggregated GHS information provided by 146 companies from 4 notifications to the ECHA C&L Inventory. Each notification may be associated with multiple companies.|H410: Very toxic to aquatic life with long lasting effects [Warning Hazardous to the aquatic environment, long-term hazard]|H361: Suspected of damaging fertility or the unborn child [Warning Reproductive toxicity]|P201, P202, P260, P281, P308+P313, P314, P405, and P501

Excerpt from ERG Guide 171 [Substances (Low to Moderate Hazard)]: SMALL FIRE: Dry chemical, CO2, water spray or regular foam. LARGE FIRE: Water spray, fog or regular foam. Do not scatter spilled material with high-pressure water streams. Move containers from fire area if you can do it without risk. Dike fire-control water for later disposal. FIRE INVOLVING TANKS: Cool containers with flooding quantities of water until well after fire is out. Withdraw immediately in case of rising sound from venting safety devices or discoloration of tank. ALWAYS stay away from tanks engulfed in fire. (ERG, 2016)

Excerpt from ERG Guide 171 [Substances (Low to Moderate Hazard)]: As an immediate precautionary measure, isolate spill or leak area in all directions for at least 50 meters (150 feet) for liquids and at least 25 meters (75 feet) for solids. SPILL: Increase, in the downwind direction, as necessary, the isolation distance shown above. FIRE: If tank, rail car or tank truck is involved in a fire, ISOLATE for 800 meters (1/2 mile) in all directions; also, consider initial evacuation for 800 meters (1/2 mile) in all directions. (ERG, 2016)

Excerpt from ERG Guide 171 [Substances (Low to Moderate Hazard)]: Do not touch or walk through spilled material. Stop leak if you can do it without risk. Prevent dust cloud. Avoid inhalation of asbestos dust. SMALL DRY SPILL: With clean shovel, place material into clean, dry container and cover loosely; move containers from spill area. SMALL SPILL: Pick up with sand or other non-combustible absorbent material and place into containers for later disposal. LARGE SPILL: Dike far ahead of liquid spill for later disposal. Cover powder spill with plastic sheet or tarp to minimize spreading. Prevent entry into waterways, sewers, basements or confined areas. (ERG, 2016)

Excerpt from ERG Guide 171 [Substances (Low to Moderate Hazard)]: Wear positive pressure self-contained breathing apparatus (SCBA). Structural firefighters' protective clothing will only provide limited protection. (ERG, 2016)

SRP: The scientific literature for the use of contact lenses in industry is conflicting. The benefit 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.

Slightly irritating to eyes, negligible irritant to skin.

SEDIMENT: Oxadiazon was detected in river sediment (organic carbon contents of 0.49-4.05 mg/g) samples collected from the Koise River tributaries in Japan during a rice cultivation period between May and September 1985 at a maximum concn of 10 ug/kg during August(1).

URBAN/SUBURBAN: Oxadiazon was not detected in the air in Kitakyashu City, Japan, an urban area 10 miles from an agricultural area, in samples collected during July 1991 and April 1992 using a single 24-hr sampling at a flow rate of 500 L/min(1).

LD50 Rat oral (acute) >3,500 mg/kg|LD50 Rat oral >5000 mg/kg|LD50 Rat percutaneous >2000 mg/kg

Oxadiazon's production and use as an herbicide(1) is expected to result in its release to the environment through various waste streams(SRC).

TERRESTRIAL FATE: Based on a classification scheme(1), reported Koc values ranging from 676 to 3,236(2-4), indicate that oxadiazon is expected to have only low or slight mobility in soil(SRC). In laboratory studies using TLC(5) and column leaching(6) methods, oxadiazon was determined to be immobile in a total of six soils. Volatilization of oxadiazon from moist soil surfaces is not expected to be an important fate process(4). Oxadiazon is not expected to volatilize from dry soil surfaces(SRC) based upon its vapor pressure of 1.15X10-7 mm Hg(7). Oxadiazon photodegrades on soil in natural sunlight with a half-life of 4.65 days(8). The photodegradation of oxadiazon results in three photoproducts with the loss of chlorine as the dominant process and the participation of hydroxyl(8). Biodegradation in soil is not expected to be an important fate process with a reported half-life of oxadiazon in aerobic soil of 3-6 months(9).|AQUATIC FATE: Based on a classification scheme(1), reported Koc values ranging from 676 to 3,236(2-4) indicate that oxadiazon is expected to adsorb to suspended solids and sediment(SRC). Volatilization from water surfaces is not expected(5) based upon an estimated Henry's Law constant of 7X10-8 atm-cu m/mole(SRC), estimated based on its vapor pressure, 1.15X10-7 mm Hg(6), and water solubility, 0.7 mg/l(7). According to a classification scheme(8), BCF values in the range of 24.1 to 708 measured in fish(9,10), suggests bioconcentration in aquatic organisms is low to high(SRC). Oxadiazon (1 ppm) photodegrades in water in natural sunlight with a half-life of 2.65 days(11). The photodegradation of oxadiazon results in three photoproducts with the loss of chlorine as the dominant process and the participation of hydroxyl(11). Oxadiazon is stable to hydrolysis at neutral and acidic pHs, but degrades slowly at pH 9, with a half-life of 38 days(12). Only 7% biodegradation was observed in a river die-away test using water from Ashai River, Japan after 50 days(13), suggesting biodegradation is slow in water.|ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), oxadiazon, which has a vapor pressure of 1.15X10-7 mm Hg at 22 °C(2), is expected to exist in both the vapor and particulate phases in the ambient atmosphere. Vapor-phase oxadiazon 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 16 hours(SRC), calculated from its rate constant of 24.3X10-12 cu cm/molecule-sec at 25 °C(SRC) determined using a structure estimation method(3). Particulate-phase oxadiazon is removed from the air by wet and dry deposition(SRC). There is the potential for the photodegradation of oxadiazon in air based upon its photodegradation in water(4); however, the rate at which this may occur is not known.

The rate constant for the vapor-phase reaction of oxadiazon with photochemically-produced hydroxyl radicals has been estimated as 24X10-12 cu cm/molecule-sec at 25 °C(SRC) using a structure estimation method(1). This corresponds to an atmospheric half-life of about 16 hours at an atmospheric concentration of 5X10+5 hydroxyl radicals per cu cm(1). Oxadiazon is stable to hydrolysis at neutral and acidic pHs, but degrades slowly at pH 9, with a half-life of 38 days(2). Oxadiazon photodegrades in natural sunlight in water (1 ppm) and on soil, with respective half-lives of 2.65 days and 4.65 days; rate differences were attributed to the attenuation of light in soil(3). The photodegradation of oxadiazon results in three photoproducts with the loss of chlorine as the dominant process and the participation of hydroxyl(3).

1.20e+03|Oxadiazon was detected in fish tissue (flesh) samples of crucian carp (Carassius cuvieri) collected from Lake Kojima in Japan at 2,4 and 9 months postapplication at concns of 0.442 ppm, 0.046 ppm and 0.017 ppm, respectively(4). At the final sampling period, the concn of oxadiazon in the surface water (0.024 ppb) was much lower than that detected in the fish samples, indicating that bioconcentration (BCF = 708 based on the point-in-time values reported) had occurred(1). In a study in which oxadiazon was introduced into a model ecosystem, adsorbed to soil (at 1 and 10 ppm), for 48 days, total residues in algae, snails and daphnids accumulated with BCFs of approximately 39-58 at both treatment rates while the respective BCFs in fish were approximately 198-248; the final concns in the water were 5.3 ppb and 44.4 ppb, respectively(2). However, in the study, only 35%, 50%, 57% and 63% of the residues recovered from the snails, fish, water and algae samples were parent oxadiazon, indicating that metabolism/degradation had occurred; the presence of the oxadiazon metabolites found in the water may have affected the bioaccumulation results(2). BCF values of 24.1-26.7 were measured in carp exposed to 40 ug/l of oxadiazon over an 8 week incubation period(3).According to a classification scheme(4), the BCF data suggests the potential for bioconcentration in aquatic organisms is low to high(SRC).

3.24e+03 L/kg|The Koc of oxadiazon is reported as ranging from 676 to 3236(1-3). According to a classification scheme(4), this estimated Koc value suggests that oxadiazon is expected to have only low or slight mobility in soil. In laboratory studies using TLC(5) and column leaching(6) methods, oxadiazon was determined to be immobile in a total of six soils. In a study of the adsorption of oxadiazon (concn of 0.1-100 ppm) to soil and container (potting) media, 98-99% of the applied oxadiazon was adsorbed at all treatment rates, indicating that adsorption was not dependent on concn(7).

The Henry's Law constant for oxadiazon is estimated as 7X10-8 atm-cu m/mole(SRC) based upon its vapor pressure, 1.15X10-7 mm Hg(1), and water solubility, 0.7 mg/l(2). This Henry's Law constant indicates that oxadiazon is expected to be essentially nonvolatile from water surfaces(3). Oxadiazon's estimated Henry's Law constant indicates that volatilization from moist soil surfaces will not occur(4). Oxadiazon is not expected to volatilize from dry soil surfaces(SRC) based upon its vapor pressure(1).

SURFACE WATER: Oxadiazon was detected in river water samples collected from the Koise River tributaries in Japan during a rice cultivation period between May and September 1985 at a maximum concn of 6.3 ug/l(1). Oxadiazon was not detected (detection limit = 0.01 ug/ml) in water samples (500 ml) collected monthly from the mouth of the Shinano River in Niigata Prefecture, Japan, during May to September 1996(2). Oxadiazon was detected (detection limit = 0.01 ug/l) in water samples collected from the Arno River, Italy, during 1992-1995, at yearly maximums of 0.11 ug/l in 1993 and 0.06 ug/l in 1995; oxadiazon was not detected in river water samples in 1992 or 1994(3).

In a 1992-1993 FDA monitoring study of oxadiazon residues in pears, the compound was not detected in any of the 710 domestic or 949 imported pear samples tested(1). Oxadiazon was not detected in a monitoring study of 6970 samples (80% domestic, 20 % foreign) of 81 commodities, including 71 pear samples, collected in Texas during 1989-1991(2).

Occupational exposure to oxadiazon may occur through inhalation and dermal contact with this compound at workplaces where oxadiazon is produced or used. (SRC)

5.89 Days

Excerpt from ERG Guide 171 [Substances (Low to Moderate Hazard)]: Inhalation of material may be harmful. Contact may cause burns to skin and eyes. Inhalation of Asbestos dust may have a damaging effect on the lungs. Fire may produce irritating, corrosive and/or toxic gases. Some liquids produce vapors that may cause dizziness or suffocation. Runoff from fire control may cause pollution. (ERG, 2016)|Teratogens

Excerpt from ERG Guide 171 [Substances (Low to Moderate Hazard)]: Ensure that medical personnel are aware of the material(s) involved and take precautions to protect themselves. Move victim to fresh air. Call 911 or emergency medical service. Give artificial respiration if victim is not breathing. Administer oxygen if breathing is difficult. Remove and isolate contaminated clothing and shoes. In case of contact with substance, immediately flush skin or eyes with running water for at least 20 minutes. (ERG, 2016)

Skin decontamination. Skin contamination should be treated promptly by washing with soap and water. Contamination of the eyes should be treated immediately by prolonged flushing of the eyes with large amounts of clean water. If dermal or ocular irritation persists, medical attention should be obtained without delay. /Other herbicides/|Gastrointestinal decontamination. Ingestions of these herbicides are likely to be followed by vomiting and diarrhea due to their irritant properties. Management depends on: (1) the best estimate of the quantity ingested, (2) time elapsed since ingestion, and (3) the clinical status of the subject. Activated charcoal is probably effective in limiting irritant effects and reducing absorption of most or all of these herbicides. Aluminum hydroxide antacids may be useful in neutralizing the irritant actions of more acidic agents. Sorbitol should be given to induce catharsis if bowel sounds are present and if spontaneous diarrhea has not already commenced. Dehydration and electrolyte disturbances may be severe enough to require oral or intravenous fluids. ... If large amounts of herbicide have been ingested and the patient is seen within an hour of the ingestion, gastrointestinal decontamination should be considered ... . If the amount of ingested herbicides was small, if effective emesis has already occurred, or if treatment is delayed, administer activated charcoal and sorbitol by mouth. /Other herbicides/|Intravenous fluids. If serious dehydration and electrolyte depletion have occurred as a result of vomiting and diarrhea, monitor blood electrolytes and fluid balance and administer intravenous infusions of glucose, normal saline, Ringer's solution, or Ringer's lactate to restore extracellular fluid volume and electrolytes. Follow this with oral nutrients as soon as fluids can be retained. /Other herbicides/|Supportive measures are ordinarily sufficient for successful management of excessive exposures to these herbicides ... . If the patient's condition deteriorates in spite of good supportive care, the operation of an alternative or additional toxicant should be suspected. /Other herbicides/|For more Antidote and Emergency Treatment (Complete) data for OXADIAZON (6 total), please visit the HSDB record page.

2-(tert-butyl)-4-(2,4-dichloro-5-isopropyloxy-phenyl) delta(2)-1,3,4-oxadiazoline-5-one

USEPA/OPP Pesticide Code 109001; Trade Names: Ronstar; RP-17623; G315.|Emulsifiable concentrates, granules, flowable, wettable powder|Tech. is greater than/equal to 94% pure

Not to be used on red fescue, bentgrass turf, dichronda or centipedegrass.

FDA Method 212.2. Organochlorine Residues (Nonionic) General Method for Nonfatty Foods Including Acetone Extraction, Isolation in Organic Phase, and Optional Florisil Column Cleanup.|FDA Method 231.1. Organophosphorous Residues General Methods for Fatty Foods Including Extraction of Fat, Acetonitrile Partition, and Florisil Column Cleanup.|HERL Method HERL_001. Modification of Mills, Onley, Gaither Method for the Determination of Multiple Organochlorine Pesticides and Metabolites in Human or Animal Adipose Tissue.|Metabolites can be determined by GLC with thermal-conductivity detection. Oxadiazon residues can be determined by GLC with electrical conductivity detection or by mass spectrometry. Residues in hops can be determined by GLC.

Agrochemicals -> Herbicides|Health Hazards -> Teratogens|Herbicides