Terbacil

216.66

216.66

227-595-1

S0017J6E25

2588

DTXSID8024317

White crystalline solid|Colorless crystals

49.4

1.89

Off-white Solid

1.34 g/cm³ @ Temp: 25 °C

175-177 °C

Sublimation begins below the melting point

1.536

In water, 710 mg/L at 25 deg C

0-6°C

4.7X10-7 mm Hg at 29.5 deg C

Oral-Rat LD50: 5000 mg/kg

Combustion produces toxic chloride and nitrogen oxide gases

Like most organic powders or crystals, under severe dusting conditions, this material may form explosive mixtures in air. /Sinbar Herbicide/

Odorless

Henry's Law constant = 1.9X10-10 atm-cu m/mol at 25 °C (est)

pKa = 9.00

146.51 Ų [M-H]-

Stable to hydrolysis in water.|Hydroxyl radical reaction rate constant = 7.49X10-12 cu cm/molec-sec at 25 °C (est)

Water soluble.

Amides and Imides

A uracil derivative.

Noncorrosive

None assigned

22

YQ9360000

Xn

Warehouse ventilated, low temperature and dry

Stable up to its m.p. Stable in aqueous alkaline media at room temperature. Stable 31 d in the dark in aqueous solution (c. pH 6, 25 deg C), and in an aqueous solution containing 0.05 M ferric chloride (c. pH 2). Stable 14 days in artificial sunlight (continuous exposure, 25 deg C). Stable 14 days in the dark (25 deg C, 54 deg C).

P264, P270, P273, P301+P312, P330, P391, P501

H302

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.|SRP: Wastewater from contaminant suppression, cleaning of protective clothing/equipment, or contaminated sites should be contained and evaluated for subject chemical or decomposition product concentrations. Concentrations shall be lower than applicable environmental discharge or disposal criteria. Alternatively, pretreatment and/or discharge to a permitted wastewater treatment facility is acceptable only after review by the governing authority and assurance that "pass through" violations will not occur. Due consideration shall be given to remediation worker exposure (inhalation, dermal and ingestion) as well as fate during treatment, transfer and disposal. If it is not practicable to manage the chemical in this fashion, it must be evaluated in accordance with EPA 40 CFR Part 261, specifically Subpart B, in order to determine the appropriate local, state and federal requirements for disposal.|PESTICIDE DISPOSAL: Wastes resulting from the use of this product may be disposed of on sit or at an approved waste disposal facility. /Sinbar Herbicide/|CONTAINER DISPOSAL: Non refillable container. Do Not reuse or refill this container. Offer for recycling, if available. Completely empty bag into application equipment. Then dispose of empty bag in a sanitary landfill or by incineration, or, if allowed by State and local authorities, by burning. If burned, stay out of smoke. /Sinbar Herbicide/|For more Disposal Methods (Complete) data for TERBACIL (7 total), please visit the HSDB record page.

USEPA/Office of Pesticide Programs; Reregistration Eligibility Decision Document - Terbacil, EPA 738-R-97-011 (January 1998). The RED summarizes the risk assessment conclusions and outlines any risk reduction measures necessary for the pesticide to continue to be registered in the U.S.[Available from, as of January 6, 2011: http://www.epa.gov/pesticides/reregistration/status.htm]

|Warning|H302 (100%): Harmful if swallowed [Warning Acute toxicity, oral]|P264, P270, P273, P301+P312, P330, P391, and P501|Aggregated GHS information provided by 55 companies from 4 notifications to the ECHA C&L Inventory. Each notification may be associated with multiple companies.|H227: Combustible liquid [Warning Flammable liquids]|P210, P260, P273, P280, P314, P370+P378, P403+P235, and P501

Applicators and other handlers must wear: Long-sleeved shirt and long pants. Chemical-resistant gloves made of any waterproof material such as polyethylene or polyvinyl chloride. Shoes plus socks. /Sinbar Herbicide/|... Restricted entry interval (REI) of 12 hours. PPE required for early entry to treated areas that is permitted under the Worker Protection Standard and that involves contact with anything that has been treated, such as plants, soil, or water, is: Coveralls. Chemical-resistant gloves made of any waterproof material. Shoes plus socks. /Sinbar Herbicide/|When handlers use closed systems, enclosed cabs or aircraft in a manner that meets the requirements listed in the Worker Protection Standard (WPS) for agricultural pesticides [40 CFR 170.240 (d)(4-6)], the handler PPE requirements may be reduced or modified as specified in the WPS. /Sinbar Herbicide/|Chemical-resistant gloves.

Nonflammable|May be ignited by heat or open flame. /Sinbar Herbicide/

Like most organic powders or crystals, under severe dusting conditions, this material may form explosive mixtures in air. /Sinbar Herbicide/

Extinguishing Media: Use extinguishing media as appropriate for combustibles involved in fire. /Sinbar Herbicide/|Wear self-contained breathing apparatus, pressure demand, MSHA/NIOSH (approved or equivalent) and full protective gear. /Sinbar Herbicide/

Do not contaminate water when cleaning of equipment or disposing of equipment washwaters or rinsate. /Sinbar Herbicide/|Small Releases: Clear area. Shut off leak if safely possible. Do not wash small spills away. Ensure adequate ventilation. Do not discharge into drains or surface waters/groundwater. Shovel material into a suitable container for disposal. If spill area is on ground near trees or other valuable plants, remove top two inches of soil after initial cleanup. Dispose as directed by pesticide product. /Sinbar Herbicide/|Large Releases: Cordon off area of spillage and dike area with dirt, sand or other inert material to prevent any further migration. Recover as much of usable product for application (best disposal practice). Handle remaining material as a small spill. /Sinbar Herbicide/|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./Residential users/|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. /Residential users/

Use this product only in accordance with its labeling and with the Worker Protection Standard, 40 CFR part 170. /Sinbar Herbicide/|Do not apply this product in a way that will contact workers or other persons, either directly or through drift. Only protected handlers may be in the area during application. /Sinbar Herbicide/|User should: Wash hands before eating, drinking, chewing gum, using tobacco or using the toilet. Users should remove clothing/PPE immediately if pesticide gets inside. Then wash thoroughly and put on clean clothing. Users should remove PPE immediately after handling this product. As soon as possible, wash thoroughly and change into clean clothing. /Sinbar Herbicide/|Do not apply directly to water, to areas where surface water is present or to intertidal areas below the mean high water mark. /Sinbar Herbicide/|For more Preventive Measures (Complete) data for TERBACIL (16 total), please visit the HSDB record page.

Terbacil may irritate the skin, eyes, and mucous membranes of the nose and throat.

Levels and total discharge of terbacil after application at rate of 4.5 kg/ha to field at Fort Pierce, FL, were measured in drainage water for 13 days. Overflow water vol highest in surface tillage (st) plots. Only 1-2% of amt applied was detected in drainage waters.

URBAN/SUBURBAN: Terbacil was not detected in 24 urban air samples from a South Jackson residential area of Hinds County, MS(1). All samples were taken April to September, 1995(1).|RURAL/REMOTE: Terbacil was not detected in 21 agricultural air samples from Rolling Fork, MS(1). All samples were taken April to September, 1995(1).

moderately toxic

LD50 Rat oral >5000 mg/kg|LD50 Rat acute oral >5,000 and <7,500 mg/kg|LD50 Rat oral 7500 mg/kg|LD50 Rabbit dermal > 5,000 mg/kg/day

/AQUATIC SPECIES/ Aquatic toxicity (TLm 48 hr, tlm= median tolerance limit): sunfish 86 ppm, carp greater than 10 (rank a--lowest toxicity category of materials tested); water flea greater than 0.5 (rank a--lowest toxicity category of materials tested); grass shrimp 42 ppm; fiddler crab 1000 ppm (highest concn tested); oyster larvae 4.9 ppm (highest concn tested). Wildlife lc50 (8-day oral): pheasant 31,450 ppm. /from table/

Terbacil's production may result in its release to the environment through various waste streams; its use as a herbicide(1) will result in its direct release to the environment(SRC).

TERRESTRIAL FATE: Based on a classification scheme(1), Koc values of 41 to 89(2-5), indicate that terbacil is expected to have very high to high mobility in soil(SRC). Volatilization of terbacil from moist soil surfaces is not expected to be an important fate process(SRC) given an estimated Henry's Law constant of 1.9X10-10 atm-cu m/mole(SRC), based upon its vapor pressure, 4.7X10-7 mm Hg(6), and water solubility, 710 mg/L(7). Terbacil is not expected to volatilize from dry soil surfaces(SRC) based upon its vapor pressure(6). Based on soil biodegradation studies where terbacil has reported half-lives of 60(8) to 653 days(2) under aerobic conditions and 235 days(2) under anaerobic conditions, biodegradation of terbacil is expected to be very slow(SRC). Extrapolated first-order photodegradation half-lives of 46 and 61 days have been reported(2).|TERRESTRIAL FATE: Terbacil was lost from orchard soil by degradation and leaching. The time required for loss of 50% in soil concentration was 5-7 months.|AQUATIC FATE: Based on a classification scheme(1), Koc values of 41 to 89(2-5), indicate that terbacil is not expected to adsorb to suspended solids and sediment(SRC). Volatilization from water surfaces is not expected(6) based upon an estimated Henry's Law constant of 1.9X10-10 atm-cu m/mole(SRC), derived from its vapor pressure, 4.7X10-7 mm Hg(7), and water solubility, 710 mg/L(8). According to a classification scheme(9), a BCF of 6(10), measured in bluegill, suggests the potential for bioconcentration in aquatic organisms is low(SRC). Based on soil biodegradation studies where terbacil exhibited reported half-lives of 60(11) to 653 days(2) under aerobic conditions and 235 days(2) under anaerobic conditions, biodegradation of terbacil is expected to be very slow(SRC). Terbacil is not expected to undergo hydrolysis in the environment due to the lack of functional groups that hydrolyze under environmental conditions(2). Radio-labeled terbacil, under natural sunlight, exhibited first-order photodegradation half-lives of 29 days in laboratory water, 37 days in river water (Brandywine River) and 54 days in water with suspended sediment (Brandywine River)(2).|ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), terbacil, which has a vapor pressure of 4.7X10-7 mm Hg at 29.5 °C(2), will exist in both the vapor and particulate phases in the ambient atmosphere. Vapor-phase terbacil 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 51 hours(SRC), calculated from its rate constant of 7.5X10-12 cu cm/molecule-sec at 25 °C(SRC) that was derived using a structure estimation method(3). Vapor-phase terbacil is also degraded in the atmosphere by reaction with ozone(SRC); the half-life for this reaction in air is estimated to be 7 days(SRC), calculated from its rate constant of 1.6X10-18 cu cm/molecule-sec at 25 °C(SRC) that was derived using a structure estimation method(3). Particulate-phase terbacil may be removed from the air by wet or dry deposition(SRC). Terbacil contains chromophores that absorb at wavelengths >290 nm(4) and therefore may be susceptible to direct photolysis by sunlight(SRC).

The rate constant for the vapor-phase reaction of terbacil with photochemically-produced hydroxyl radicals has been estimated as 7.5X10-12 cu cm/molecule-sec at 25 °C(SRC) using a structure estimation method(1). This corresponds to an atmospheric half-life of about 51 hours at an atmospheric concentration of 5X10+5 hydroxyl radicals per cu cm(1). The rate constant for the vapor-phase reaction of terbacil with ozone has been estimated as 1.6X10-18 cu cm/molecule-sec at 25 °C(SRC) that was derived using a structure estimation method(1). This corresponds to an atmospheric half-life of about 7 days at an atmospheric concentration of 7X10+11 ozone molecules per cu cm(2). Terbacil is not expected to undergo hydrolysis in the environment due to the lack of functional groups that hydrolyze under environmental conditions(3). Radio-labeled terbacil, under natural sunlight, had first-order photodegradation half-lives of 29 days in standard reference water, 37 days in river water (Brandywine River) and 54 days in water with suspended sediment (Brandywine River)(4). Under UV light from fluorescent and black lights, radio-labeled terbacil had first-order photodegradation half-lives of 44 days in laboratory water and 83 days in river water (Brandywine)(4). Major photodegradation products (>10% of applied) were 5-chloro-6-methyluracil, 3-tert-butyl-6-methyluracil, and 6-chloro-2,3-dihydro-3,3,7-trimethyl-5H oxazolo (3,2-a)-pyrimidine-5-one(4). Terbacil, at 250 ppm, was photolytically stable in non-buffered aqueous solutions (pH 4-10) irradiated with a mercury vapor lamp at 25 °C(4). Humic acid was not an effective sensitizer of terbacil in aqueous solutions(4). Radio-labeled terbacil (1.2 lbs/acre) had an extrapolated first-order degradation half-life of 61 days on a Drummer silty clay loam when continuously irradiated for 15 days with a xenon arc lamp at 25 °C(4). In an ancillary study, radio-labeled terbacil had a first-order degradation half-life of 46 days on a Keyport silt loam when continuously irradiated with fluorescent sun lamps and black light (1500 uW/cm ) for 8 weeks(4). The major degradate (>10% of applied) was 5-chloro-6-methyluracil(4).|Terbacil is rapidly decomposed by sunlight in the presence of sensitizers like methylene blue (1.0 ppm), rose Bengal (2.0 ppm) and riboflavin (4.0 ppm). The best results were obtained in the alkaline range of pH. At least 70 or 75% (at pH 9.1) and 25 or 60% (at pH 8.2) of the initial amounts of terbacil decomposed in the first 2 hr of irradiation, using the sensitizers(1).

A BCF of 6 was reported for terbacil in bluegill (Lepomis macrochirus) which were exposed over a 4-week period(1). According to a classification scheme(2), this BCF suggests bioconcentration in aquatic organisms is low(SRC). Radio-labeled terbacil (0.01 and 1.00 ug/mL) was accumulated, respectively, at concentrations of 0.11 and 7.9 ug/g in viscera, 0.02 and 1.8 ug/g in head, 0.07 and 4.4 ug/g in the livers, and 0.02 and 1.7 ug/g in edible tissues of bluegill sunfish over 4 week exposure period(3). Terbacil residues in all fish tissues declined below the detection limit (<0.01 ug/g) during a 3 day depuration period(3).

45.71 L/kg|The Koc of terbacil ranges from 41 to 89(1-4). According to a classification scheme(5), these Koc values suggest that terbacil is expected to have high to very high mobility in soil(SRC). Radio-labeled terbacil (0.3-6.3 ug/mL) had a Freundlich adsorption coefficient of 0.39 ml/g (Koc = 61) in Woodstown sandy loam, 0.71 mL/g (Koc = 58) in Cecil sandy loam; 1.3 mL/g (Koc = 52), 1.2 mL/g (Koc = 44) in a Keyport silt loam(1). Radio-labeled terbacil had Freundlich adsorption coefficient of 2.46 mL/g (Koc = 64) in a Webster silty clay loam, 0.38 mL/g (Koc = 42) in a Cecil sandy loam, 0.38 mL/g (Koc = 76) in a Glendale sandy clay loam, and 0.12 mL/g (Koc = 21) in Eustis fine sand(1). Radio-labeled terbacil, at 1 ug/mL, had Freundlich adsorption coefficients ranging from 0.7-1.6 mL/g (Koc = 58-85) for twelve mineral soils(1).

The Henry's Law constant for terbacil is estimated as 1.9X10-10 atm-cu m/mole(SRC) derived from its vapor pressure, 4.7X10-7 mm Hg(1) at 29.5 °C, and water solubility, 710 mg/L(2). This Henry's Law constant indicates that terbacil is expected to be essentially nonvolatile from moist soil and water surfaces(3). Terbacil is not expected to volatilize from dry soil surfaces(SRC) based upon its vapor pressure(1).

GROUNDWATER: Terbacil was detected in 28 of 5043 groundwater samples, collected under the National Water Quality Assessment program run 1992 to 2001, at a maximum concentration of 0.891 ug/L, <0.034 ug/L was the reported detection limit(1). The EPA Pesticides in Ground Water Database reports 6 detections of terbacil (ranging from 0.3-8.9 ug/L) out of 288 wells tested in six states (CA, LA, MS, OR, WA, WV)(2). Terbacil was detected in 0.5% of groundwater samples collected from agricultural and urban areas in the United States, as part of the Nation Water Quality Assessment Program, at a max concentration of 0.33 ug/L(3). Terbacil was not detected in 18 row crop, 20 orchard and 34 public supply groundwater wells sampled 1993 to 1995 from the Central Columbia Plateau, WA(4). Terbacil was detected in one of the 20 orchard wells when the same wells were tested again 2002 to 2003, detection limits varied and were not reported as this was a trend study(4). Of 20 wells sampled in WV apple and peach orchards May to Oct 1985, five contained terbacil at 0.3 to 1.2 ppb; the same 20 wells were sampled again April to Oct 1986, no terbacil was detected in these samples(5). Terbacil was detected in <2% of samples from 208 wells located in 9 urban land use studies(6).|SURFACE WATER: Terbacil was detected in 121 of 3810 surface water samples, collected under the National Water Quality Assessment program run 1992 to 2001, at a maximum concentration of 0.54 ug/L, <0.034 ug/L was the reported detection limit(1). Terbacil was detected in one of 142 samples from four locations in the San Joaquin River basin at a concentration of 0.008 ug/L (detection limit 0.007 ug/L), samples were taken from Jan to Dec 1993(2). Terbacil was detected in 40 of 98 surface water samples taken from the Yakima River basin, WA at concentrations of <0.007 to 0.448 ug/L in samples taken May 1999 to Jan 2000(3). Terbacil was detected in 0.9% of 215 surface water samples taken from 8 urban US streams (Norwalk, CT; Denver, CO; Washington, DC; Tallahassee, FL; Atlanta, GA; Las Vegas, NV; Albany, NY; Portland, OR) at a maximum of 0.035 ug/L in samples taken 1993 to 1995(4). Surface water samples taken from US streams in the Great Lakes basin tested positive in 76% of 165 samples taken 1994 to 2000 at concentrations of 0.001 to 0.106 ug/L(5).|RAIN: Terbacil was detected in one of 21 agricultural rain samples and not detected in 24 urban rain samples, samples were taken April to September 1995, from Hinds County, MS(1).

At manufacturing level, industrial exposure is rather limited due to normal control measures. However, industrial (ie, railroad) and agricultural workers are exposed to the wettable powders and aqueous emulsions. There are two primary routes of exposure--inhalation of dusts and sprays and skin contact with dusts and emulsions and sprays.|Occupational exposure to terbacil may occur through inhalation and dermal contact with this compound at workplaces where terbacil is produced or used(SRC). Workers involved in agricultural spraying operations may be exposed to terbacil via dermal contact and inhalation of dust(1). Monitoring and use data indicate that the general population may be exposed to terbacil via dermal contact with contaminated water or products containing terbacil(SRC).

... Beagle dogs ... fed diets containing terbacil. ... Main metabolite /in urine/ was 3-tert-butyl-5-chloro-6-hydroxymethyluracil. ... Other/s/ ... observed: 6-chloro-2,3-dihydro-7-(hydroxymethyl)-3,3-dimethyl-5h-oxazolo- (3,2-a)pyrimidin-5-one; 6-chloro-2,3-dihydro-3,3,7-trimethyl- 5H-oxazolo(3,2-a)pyrimidin-5-one; 3-tert-butyl-6-hydroxymethyluracil /&/ 3-tert-butyl-6-formyluracil ... .|Terbacil is metabolized to 3-tert-butyl-5-chloro-6-(hydroxymethyl) uracil, excreted in dogs fed with a diet incorporating terbacil.|Oxidation of a methyl group and the tert-butyl group gives the oxidative products of terbacil, which are than cyclized to form an oxazolidine ring.|Orange seedlings were grown in solutions containing (14)C-terbacil. Analysis of plant tissues showed the presence of the 6-hydroxymethyl analog and a conjugate believed to be the beta-glucoside.|For more Metabolism/Metabolites (Complete) data for TERBACIL (7 total), please visit the HSDB record page.

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/|Activated charcoal is probably effective in limiting irritant effects and reducing absorption of most or all of these herbicides. /Other herbicides/|If serious dehydration and electrolyte depletion have occurred as a result of vomiting and diarrhea, monitor blood electrolytes and 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. Fluids serve to support excretion of the toxicants. Supportive measures are ordinarily sufficient for successful management of excessive exposures to these herbicides. /Other Herbicides/|/SRP:/ Immediate first aid: Ensure that adequate decontamination has been carried out. If patient is not breathing, start artificial respiration, preferably with a demand valve resuscitator, bag-valve-mask device, or pocket mask, as trained. Perform CPR if necessary. Immediately flush contaminated eyes with gently flowing water. Do not induce vomiting. If vomiting occurs, lean patient forward or place on the left side (head-down position, if possible) to maintain an open airway and prevent aspiration. Keep patient quiet and maintain normal body temperature. Obtain medical attention. /Poisons A and B/|For more Antidote and Emergency Treatment (Complete) data for TERBACIL (6 total), please visit the HSDB record page.

3-tert-butyl-5-chloro-6-methyluracil

The estimated annual agricultural use of terbacil during 1992 in the United States was approximately 285,000 lbs.

Wettable powder|Composition: Technical is 97%|Sinbar Herbicide (Tessenderlo Kerley, Inc.) 80% Terbacil|Terbacil Technical Herbicide (Tessenderlo Kerley, Inc.) 97.5% Terbacil|For more Formulations/Preparations (Complete) data for TERBACIL (7 total), please visit the HSDB record page.

The WHO Recommended Classification of Pesticides by Hazard identifies terbacil as unlikely to present an acute hazard in normal use; Main Use: herbicide.

Method: AOAC 991.07; Procedure: gas chromatography using a nitrogen-phosphorus detector; Analyte: terbacil; Matrix: finished drinking water; Detection Limit: 4.5 ug/L.|Method: ASTM D5475; Procedure: gas chromatography with a nitrogen-phosphorus detector; Analyte: terbacil; Matrix: ground water and finished drinking water; Detection Limit: 4.5 ug/L.|Method: EPA-NERL 525.2; Procedure: gas chromatography/mass spectrometry; Analyte: terbacil; Matrix: finished drinking water, source water, or drinking water in any treatment stage; Detection Limit: 2.1ug/L.|Method: EPA-TSC/NERL 507; Procedure: gas chromatography with a nitrogen-phosphorus detector; Analyte: terbacil; Matrix: ground water and finished drinking water; Detection Limit: 0.56 ug/L.|For more Analytic Laboratory Methods (Complete) data for TERBACIL (10 total), please visit the HSDB record page.

Determination of terbacil in biological materials submitted for forensic examination in cases of suspected poisonings by gas chromatography with flame ionization.

Agrochemicals -> Herbicides|Pharmaceuticals