Terbutryn

WHITE, CRYSTALLINE

White powder

Readily soluble in organic solvents

Solubilities in organic solvents at 20 °C [Table#3219]

READILY SOL IN ETHYLGLYCOL MONOETHYL ETHER, ISOPROPANOL AND XYLENE AT 20-25 °C

Also readily soluble in dioxane, diethyl ether, xylene, chloroform, carbon tetrachloride, dimethylformamide. Slightly soluble in petroleum ether.

In water, 25 mg/L at 20 °C

35.9 [ug/mL] (The mean of the results at pH 7.4)

0.00000169 [mmHg]

1.69X10-6 mm Hg at 25 °C

Stable under normal conditions. The methylthio group is hydrolized in the presence of strong acids or alkalis.

Estimated shelf life of 80w formulation at least 5 yr, with only slight sensitivity to natural light & extreme temp which would occur normally.

This chemical does not meet GHS hazard criteria for 1.5% (5 of 343) of reports.

Warning

H302 (52.2%): Harmful if swallowed [Warning Acute toxicity, oral]；H317 (59.5%): May cause an allergic skin reaction [Warning Sensitization, Skin]；H319 (11.4%): Causes serious eye irritation [Warning Serious eye damage/eye irritation]；H332 (10.8%): Harmful if inhaled [Warning Acute toxicity, inhalation]；H400 (95.9%): Very toxic to aquatic life [Warning Hazardous to the aquatic environment, acute hazard]；H410 (86.6%): Very toxic to aquatic life with long lasting effects [Warning Hazardous to the aquatic environment, long-term hazard]

P261, P264, P264+P265, P270, P271, P272, P273, P280, P301+P317, P302+P352, P304+P340, P305+P351+P338, P317, P321, P330, P333+P317, P337+P317, P362+P364, P391, and P501 (click each P-code to see the statement)

Aggregated GHS information provided per 343 reports by companies from 22 notifications to the ECHA C&L Inventory. Each notification may be associated with multiple companies.；Reported as not meeting GHS hazard criteria per 5 of 343 reports by companies.；There are 21 notifications provided by 338 of 343 reports by companies with hazard statement code(s).；Information may vary between notifications depending on impurities, additives, and other factors. The percentage value in parenthesis indicates the notified classification ratio from companies that provide hazard codes. Only hazard codes with percentage values above 10% are shown. For more detailed information, please visit ECHA C&L website.

Chemical: 1,3,5-Triazine-2,4-diamine, N-(1,1-dimethylethyl)-N'-ethyl-6-(methylthio)-

2002/2076

Terbutryn: Does not have an individual approval but may be used under an appropriate group standard

For the triazine herbicides, systemic toxicity unlikely unless large amounts are ingested; May cause irritation; [EPA Pesticides, p. 121] Causes ataxia, dyspnea, and convulsions in lethal-dose animal experiments; [HSDB] An eye irritant; [MSDSonline]

The major hazards encountered in the use and handling of terbutryne stem from its toxicologic properties. Toxic by all routes (ie, inhalation, ingestion, dermal contact), exposure to this colorless to white, crystalline substance may occur from its manufacture, formulation, and use as an herbicide. Effects from exposure may include skin and eye irritation, nausea, diarrhea, shortness of breath, muscle spasms, ataxia, and anorexia. In activities and situations where over exposure may occur, wear a self-contained breathing apparatus and personal protective clothing. If contact should occur, immediately flush affected skin or eyes with running water for at least 15 minutes. Remove contaminated clothing and shoes at the site. While terbutryne does not ignite easily, it may burn with the production of irritating and poisonous gases. For fires involving terbutryne, extinguish with dry chemical, CO2, Halon, water spray, fog, or standard foam. Terbutryne may be shipped domestically via air, rail, road, and water, in containers bearing the label "Poison". Small dry spills of terbutryne may be placed into a clean, dry, covered container for later disposal (liquid solutions are first absorbed in sand or other noncombustible absorbent). Large liquid spills should be diked far ahead to prevent terbutryne from entering water sources and sewers. Before implementing land disposal of terbutryne, consult with regulatory agencies for guidance.

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 future use. Under this pesticide reregistration program, EPA examines health and safety data for pesticide active ingredients initially registered before November 1, 1984, and determines whether they are eligible for reregistration. In addition, all pesticides must meet the new safety standard of the Food Quality Protection Act of 1996. Terbutryn is found on List A, which contains most food use pesticides and consists of the 194 chemical cases (or 350 individual active ingredients) for which EPA issued registration standards prior to FIFRA, as amended in 1988. Case No: 0085; Pesticide type: herbicide; Registration Standard Date: 09/17/86; Case Status: No products containing the pesticide are actively registered ... The case /is characterized/ as "cancelled." Under FIFRA, pesticide producers may voluntarily cancel their registered products. EPA also may cancel pesticide registrations if registrants fail to pay required fees or make/meet certain reregistration commitments, or if EPA reaches findings of unreasonable adverse effects.; Active ingredient (AI): Terbutryn; AI Status: The active ingredient is no longer contained in any registered pesticide products ... "cancelled."

No person may /transport,/ offer or accept a hazardous material for transportation in commerce unless that person is registered in conformance ... and the hazardous material is properly classed, described, packaged, marked, labeled, and in condition for shipment as required or authorized by ... /the hazardous materials regulations (49 CFR 171-177)./

The International Air Transport Association (IATA) Dangerous Goods Regulations are published by the IATA Dangerous Goods Board pursuant to IATA Resolutions 618 and 619 and constitute a manual of industry carrier regulations to be followed by all IATA Member airlines when transporting hazardous materials.

The International Maritime Dangerous Goods Code lays down basic principles for transporting hazardous chemicals. Detailed recommendations for individual substances and a number of recommendations for good practice are included in the classes dealing with such substances. A general index of technical names has also been compiled. This index should always be consulted when attempting to locate the appropriate procedures to be used when shipping any substance or article.

If material on fire or involved in fire: Extinguish fire using agent suitable for type of surrounding fire. (Material itself does not burn or burns with difficulty.) Use water in flooding quantities as fog. Use "alcohol" foam, carbon dioxide or dry chemical. /Triazine pesticides, solid, NOS/

Environmental considerations- land spill: Dig a pit, pond, lagoon, holding area to contain liquid or solid material. /SRP: If time permits, pits, ponds, lagoons, soak holes, or holding areas should be sealed with an impermeable flexible membrane liner./ Cover solids with a plastic sheet to prevent dissolving in rain or fire fighting water. Dike surface flow using soil, sand bags, foamed polyurethane, or foamed concrete. /Triazine pesticides, solid, NOS/

Environmental considerations- water spill: Use natural barriers or oil spill control booms to limit spill travel. Use natural deep water pockets, excavated lagoons, or sand bag barriers to trap material at bottom. Remove trapped material with suction hoses /Triazine pesticides, solid, NOS/

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.

Noncombustible containers should be crushed & buried under more than 40 cm of soil. /Herbicides/

Group I Containers: Combustible containers from organic or metallo-organic pesticides (except organic mercury, lead, cadmium, or arsenic compounds) should be disposed of in pesticide incinerators or in specified landfill sites. /Organic or metallo-organic pesticides/

Group II Containers: Noncombustible containers from organic or metallo-organic pesticides (except organic mercury, lead, cadmium, or arsenic compounds) must first be triple rinsed. Containers that are in good condition may be returned to the manufacturer or formulator of the pesticide product, or to a drum reconditioner for reuse with the same type of pesticide product, if such reuse is legal under Department of Transportation regulations (eg 49 CFR 173.28). Containers that are not to be reused should be punctured ... and transported to a scrap metal facility for recycling, disposal or burial in a designated landfill. /Organic or metallo-organic pesticides/

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.

Avoid contact with eyes, contact with skin, inhalation of dust, & contamination of food & feed.

Only clean clothing ... should be worn & clothing should be changed daily ... Adequate sanitary facilites & washing water should be provided for workers to wash before meals. Smoking & consumption of alcoholic drinks before & during the handling of herbicides should be forbidden. Contaminated clothing should be removed immediately & a hot bath taken if possible. Personal hygiene should be encouraged. /Herbicides/

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.

For more Preventive Measures (Complete) data for TERBUTRYNE (6 total), please visit the HSDB record page.

The use of personal protective equipment such as glasses, synthetic gloves & /NIOSH/ approved breathing apparatus/ ... is important. /Herbicides/

Personnel protection: ... Wear appropriate chemical protective gloves, boots and goggles. ... Wear positive pressure self-contained breathing apparatus when fighting fires involving this material. /Triazine pesticides, solid NOS/

LD50 Anas platyrhynchos (mallard ducks) oral greater than 2000 mg/kg, 3-4 mo old female /Sample purity 97.8%/

LD50 Pheasant oral greater than 2000 mg/kg, 3 mo old female /Sample purity 97.8%/

LC50; Species: Oncorhynchus mykiss (Rainbow trout, length 2-10 cm, weight 0.5-14 g); Conditions: freshwater; static, 14 °C, pH 6.8-7.6, hardness 5.0-6.0 mg/L CaCO3, dissolved oxygen 12 mg/L; Concentration: 3.0 mg/L for 48 hr

LC50 Oncorhynchus mykiss (Rainbow trout, weight 0.8 g) 0.82 mg/L/96 hr at 13 °C (95% confidence limit: 0.56-1.20 mg/L) /static bioassay/

For more Ecotoxicity Values (Complete) data for TERBUTRYNE (16 total), please visit the HSDB record page.

TERRESTRIAL FATE: Based on a classification scheme(1), Koc values of 366 - 41,757(2) indicate that terbutryne is expected to have moderate mobility to immobility in soil(SRC). Terbutryne volatilized 6% and <1% in 50 days from a sandy soil (pH 7.9, 97% sand, 0.3% clay, 1.0% organic matter) at 25 and 15 °C, respectively(3). Terbutryne volatilized 3% and <1% in 50 days from another soil (pH 8.9, 49% sand, 29% clay, 1.3% organic matter) at 25 and 15 °C, respectively(3). Terbutryne is not expected to volatilize from dry soil surfaces(SRC) based upon its vapor pressure, 1.69X10-6 mm Hg(4). Terbutryne may be susceptible to biodegradation based upon half-lives of 2 and 11 weeks in unfumigated and fumigated soil, respectively(5).

AQUATIC FATE: Based on a classification scheme(1), Koc values of 366 - 41,757(2) indicate that terbutryne 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 2.1X10-8 atm-cu m/mole(SRC), derived from its vapor pressure, 1.69X10-6 mm Hg(4), and water solubility, 25 mg/L(5). Sensitized photolysis and photooxidation of terbutryne with photochemically produced hydroxyl radicals may be important removal mechanisms(6-7). According to a classification scheme(8), an estimated BCF of 72(SRC) from its log Kow, 3.74(9) and a regression-derived equation(10) and a reported BCF of 25 in catfish(11) suggest the potential for bioconcentration in aquatic organisms is low to moderate(SRC). Terbutryne had a degradation half-lives of 6.9 - 30 days in river and pond waters under different conditions(12,1).

AQUATIC FATE: HALF-LIFE OF TERBUTRYN IN POND WATER WAS 20-30 DAYS. IN BOTTOM SEDIMENT, CORRESPONDING VALUE WAS 400 DAYS.

ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), terbutryne, which has a vapor pressure of 1.69X10-6 mm Hg at 25 °C(2), will exist in both the vapor and particulate phases in the ambient atmosphere. Vapor-phase terbutryne 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 36 hours(SRC), calculated from its rate constant of 1.1X10-11 cu cm/molecule-sec at 25 °C(SRC) that was derived using a structure estimation method(3). Terbutryne may be susceptible to sensitized photolysis(4) and photooxidation by photochemically produced hydroxyl radicals(5) based upon data for other methylthio-s-triazine herbicides such as prometryne(5) and ametryne(4).

/BIRDS and MAMMALS/ Practically nontoxic. Bird: Practically nontoxic to upland game birds.

/BIRDS and MAMMALS/ The effect of terbutryne on the vitamin A content in the liver of pheasants (Phasianus colchicus colchicus L.) was studied. One hundred forty 10-18 week old pheasants were fed grains treated with terbutryne ad libitum for 4 to 20 days. A significant decrease in the vitamin A content of the liver was observed starting from the 20th day, and reaching 56% of the initial level by 2 weeks after treatment. The reduction of the liver vitamin A level is indicative of the harmful effect of terbutryne.

/AQUATIC SPECIES/ Igran in aquatic environment had adverse effect on its population, especially fish. The median lethal effect on carp of exposure for 1-4 days was 8-9 mg/cu m. the toxicity to Leucaspius delineatus was twice that to Carp.

/AQUATIC SPECIES/ The effects of the herbicide terbutryn on a simple lotic food web were investigated during a 72-day exposure period in five artificial indoor streams in a greenhouse. The model compound terbutryn, an s-triazine and an inhibitor of photosynthesis, was applied once in each stream at nominal concentrations of 0.6, 6, 60, or 600 ug/L. Terbutryn concentrations in the water were analyzed by gas chromatography/mass spectrometry, and an overall time to 50% dissipation (DT50) of 28 days was calculated. The development of aufwuchs and the population growth and development of the oligochaete Lumbriculus variegatus were investigated. ... Terbutryn was toxic to L. variegatus at 23.7 mg/L (96-hr median lethal concentration (LC50)) and 16.5 mg/L (96-hr median effective concentration (EC50)) in static acute toxicity tests. Terbutryn decreased aufwuchs production at 0.6 ug/L in the experimental streams. Population growth of L. variegatus was decreased by 50% at 6 ug/L. The effect of terbutryn on the aufwuchs was a direct effect of decreases in the periphyton. However, the effects on L. variegatus were an indirect effect of terbutryn as a consequence of decrease in the aufwuchs food source and occurred at three-orders-of-magnitude-lower concentrations of terbutryn than the acute toxicity effects. Our study demonstrates the utility of indoor lotic microcosm studies for evaluating both direct and indirect effects of contaminants on aquatic ecosystems.

For more Ecotoxicity Excerpts (Complete) data for TERBUTRYNE (10 total), please visit the HSDB record page.

Terbutryn

Hematologic

1 x 10 ^-3 mg/kg-day

Data from the UK data base as of 1993 gave Koc value ranges from 700 to 11,660 with a mean value of 2863.11(1). Koc values were measured for two Kishon River, Israel sediments; Kfar Yehushua was 389.57 (7.1 pH, 30% sand, 30% silt 40% clay 1.63% TOC) and Haifa industrial area was 729.60 (6.8 pH, 30 % sand, 20% silt, 50% clay, 1.25% TOC)(2). Koc values were analyzed for terbutryne in 5 EUROSOILS (country, %Clay, % organic carbon, pH); EUROSOIL1- 41,757 (Italy, 75, 1.3, 5.1), EUROSOIL2- 372.7 (Greece, 22.6, 3.7, 7.4), EUROSOIL3- 788 (United Kingdom, 17.0, 3.45, 5.2), EUROSOIL4- 366.2 (France, 20.3, 1.55, 6.5), EUROSOIL5- 3539 (Germany, 6.0, 9.25, 3.2)(3). Another measured Koc value of 700 was given for an unspecified soil type(4). According to a classification scheme(5), Koc values of 150 to 500 indicate moderate mobility and >5,000 indicate immobility in soil(SRC).

Terbutryne was classified as immobile in soil thin-layer and thick-layer chromatography and soil-column leaching experiments with sandy loam and silty clay soils in which the Rf range for terbutryne was 0.00-0.10(1). Adsorption of 96-98% and 86-97%, respectively, of the terbutryne applied to an unlimed and limed silt loam soil has been observed(2). Evidence has been reported that indicates that the basicity of s-triazine herbicides, such as terbutryne, is not the main factor governing adsorption to soil humic acids(3). It has been shown that the ability of s-triazines herbicides to act as electron donors to electron acceptor quinone-like units of humic acids also plays an important role in the adsorption(4). Adsorption of terbutryne is favored in soils containing higher concn of clay and organic matter and leaching is limited by adsorption to certain soil constituents(5). Adsorption is reversible and desorption can occur readily depending on conditions including temperature, moisture, and pH(5). Simulated field conditions for a loam soil (pH 7.8, 63.4% sand, 24.6% silt, 12.0% clay, 1.01% organic matter), under saturated field conditions and an application rate of 10 kg/ha of terbutryne gave leaching results of; 5.25, 0.30, 0.03, <0.01, and <0.01 ppm at depths of 0 to 6, 6 to 12, 12 to 18, 18 to 24, and 24 to 30 cm, respectively, after 10 days(6). Terbutryne was found at 0.3% of the applied amount in runoff water and sediment from a rain water simulated sample after 12 hours from unlimed soil(7).

/SIGNS AND SYMPTOMS/ Adverse effects have occurred only rarely as result of ... contact with these herbicides. Most injuries reported have been skin irritation after prolonged contact. In varying degrees these herbicides are likely to produce irritation of gut if ingested in substantial quantity. ... Some compounds of these classes cause irritation of eyes and mucous membranes, particularly if direct contact is protracted. Nausea, vomiting, and diarrhea can be expected to result from ingestion of large quantities. /Urea-, uracil- and triazine-based herbicides/

/GENOTOXICITY/ ... In this study, the DNA-damaging ability of the herbicide was evaluated in the alkaline single-cell microgel-electrophoresis ("comet") assay by testing terbutryn in the presence of S9 mix (rat liver homogenate containing microsomal enzymes plus cofactors) prepared with liver homogenate from both uninduced (basal) and Aroclor 1254-induced rats. DNA damage was recorded in freshly isolated human peripheral blood leukocytes. A statistically significant increase in the extent of primary DNA damage, more pronounced in the absence of S9 mix, took place only when terbutryn concentrations were high (100 and 150 ug/mL), in the presence of a concomitant mild cytotoxic effect.

Terbutryne's production may result in its release to the environment through various waste streams; its use as a selective herbicide for control of annual broadleaf and grassy weeds(1) will result in its direct release to the environment(SRC).

Residues of terbutryne can enter the environment (soil & water) from runoffs from irrigated fields.

AEROBIC: Degradation of terbutryne was analyzed in soil (pH 6.68, 11.54% clay, 64.81% sand, 1.75% organic matter) using a packed core method to give a half-life of 161 (4 °C and 10% moisture content), 31 (25 °C and 10% moisture content), 17 (32 °C and 10% moisture content), 36 (25 °C and 7% moisture content), and 17 days (25 °C and 13% moisture content)(1). In another soil (pH 7.69, 18.22% clay, 44.34% sand, 0.97% organic matter) also using a packed core method half-lives of 227 (4 °C and 10% moisture content), 19 (25 °C and 10% moisture content), 14 (32 °C and 10% moisture content), 31 (25 °C and 7% moisture content), and 14 days (25 °C and 13% moisture content) were given(1). Degradation of terbutryne was analyzed in soil (pH 6.68, 11.54% clay, 64.81% sand, 1.75% organic matter) using a flask method to give a half-life of 17 (4 °C and 10% moisture content), 13 (25 °C and 10% moisture content), 7 (32 °C and 10% moisture content), 9 (25 °C and 7% moisture content), and 9 days (25 °C and 13% moisture content)(1). In another soil (pH 7.69, 18.22% clay, 44.34% sand, 0.97% organic matter), also using a flask method, half-lives of 58 (4 °C and 10% moisture content), 13 (25 °C and 10% moisture content), 8 (32 °C and 10% moisture content), 19 (25 °C and 7% moisture content), and 8 days (25 °C and 13% moisture content) were given(1). Terbutryne degradation in soil which was sterilized by methyl bromide (fumigated) or by solar heating was much slower (half-life approx 11 weeks) than in the soil which was not sterilized (half-life approx 2 weeks)(2). The suppression of terbutryne degradation in the fumigated soil was still evident 8 months after fumigation, similar to the behavior found in autoclaved soil(2). Addition of fungicides also strongly inhibited the degradation of terbutryne in soil(2). These observations suggest that biodegradation accounted for the majority of the terbutryne degradation in soil in these experiments(2). Data from the UK data base as of 1993 gave

AEROBIC: Half-lives of 240 and 180 days have been reported for degradation of terbutryne in pond and river sediment under static aerobic conditions (loosely capped flasks), respectively(1). Terbutryne had a degradation half-life of 18.2 days following a 40 day lag phase in Nile River water and a 6.9 day half-life after a 38 day lag phase in Nile River water with domestic settled sewage added(2). Terbutryne was applied to 2 farm ponds (A and C) near Winnipeg, Canada, in June 1978 to give 100 ug/L water concentrations(3). The half-life for terbutryne in the ponds ranged from 3 wk in pond C, which contained growths of cattails and duckweed to 30 days in pond A which was free from aquatic macrophytes(3). Biological oxidation of the methylthio-sulfur in terbutryne may occur based upon the report that the methylthio group of the structurally similar herbicide prometryne is oxidized by soil microorganisms to the sulfoxide and sulfone(4). Adaptation and enrichment of viable microbial populations may be necessary for the degradation of methylthio-s-triazines such as terbutryne(5).

Chemical: 1,3,5-Triazine-2,4-diamine, N-(1,1-dimethylethyl)-N'-ethyl-6-(methylthio)-

2002/2076

Terbutryn: Does not have an individual approval but may be used under an appropriate group standard

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 future use. Under this pesticide reregistration program, EPA examines health and safety data for pesticide active ingredients initially registered before November 1, 1984, and determines whether they are eligible for reregistration. In addition, all pesticides must meet the new safety standard of the Food Quality Protection Act of 1996. Terbutryn is found on List A, which contains most food use pesticides and consists of the 194 chemical cases (or 350 individual active ingredients) for which EPA issued registration standards prior to FIFRA, as amended in 1988. Case No: 0085; Pesticide type: herbicide; Registration Standard Date: 09/17/86; Case Status: No products containing the pesticide are actively registered ... The case /is characterized/ as "cancelled." Under FIFRA, pesticide producers may voluntarily cancel their registered products. EPA also may cancel pesticide registrations if registrants fail to pay required fees or make/meet certain reregistration commitments, or if EPA reaches findings of unreasonable adverse effects.; Active ingredient (AI): Terbutryn; AI Status: The active ingredient is no longer contained in any registered pesticide products ... "cancelled."

... Their chief mode of action appears to involve carbohydrate metabolism. The chlorinated s-triazines inhibit starch accumulation by blocking the prodn of sugars. Similar behavior has been shown for the methoxy & methylthio-s-triazines. It has been reported that the s-triazines affect the tricarboxylic acid cycle with activation of phospho-phenyl pyruvate-carboxylase causing the disappearance of sucrose & glyceric acid with the formation of aspartic & malic acids. /S-triazines/

Inhibition of photosynthesis by disruption of light reactions and blockade of electron transport is the mechanism of action of the 1,3,5-triazine herbicides. /1,3,5-Triazines, from table/

The influence of some s-triazine herbicides on acid phosphatase and phosphodiesterase from corn (Zea mays) roots were investigated. Terbutryn stimulated both phosphatases, whereas prometryn stimulated only the phosphodiesterase. Atrazine desmetryn, prometon, and simazine inhibited acid phosphatase. No effect was exerted by ametryn. The enzyme assays and the kinetic parameters demonstrated that the interferences observed were due to an action on the synthesis of one or both enzymes rather than on the enzyme reactions. The types of the N-alkyl and the chlorine-subsitutuent groups in the structures of the s-triazines tested appear important in determing the degree of the interference.

Terbutryn ... was metabolized by both rats and goats after a single oral dose by one or more of the following pathways: S-demethylation, conversion of thiomethyl into hydroxyl, N-de-ethylation, oxidation of the terminal carbon of the ethyl group to a carboxylic acid, oxidation of a terminal carbon of the t-butyl group to an alcohol or a carboxylic acid, or conjugation with glucuronic acid.

Carbon-labeled terbutryn was admin as single oral doses to rats and goats. Urine was collected at intervals up to 72 hr and then analyzed ... after isolation of glucuronides by chromatographic procedures. Five conjugates isolated and identified were: 2-amino-4-(t-butylamino)-6-(S-glucuronyl)-s-triazine; 2-(t-butylamino)-4-ethylamino-6-(S-glucuronyl)-s-triazine; 2-ethyl-amino-(2-methyl)glucuronylpropyl)amino-6-(S-methylthio)-s-triazine; 2-amino-4-(2-(1-glucuronyl-2-methylpropyl)amino)-6-methylthio-s-triazine; 2-ethylamino-4-(2-(2-methyl propan-1-olyl)amino)-6-(S-glucuronyl)-s-triazine.

After administration of terbutryne to rats, urinary metabolites observed ... included: 2-hydroxy terbutryne; 2-amino-4-hydroxy-6-t-butylamino-s-triazine; 2-amino-4-t-butylamino-6-mercapto-s-triazine; two S-glucuronides and two t-butyl-O-glucuronides. Other metabolites were formed by one or a combination of the following reactions: N-alkyl oxidation to alcohols or acids: S-demethylation; N-deethylation; and disulfide formation.

Microsomes prepared from livers from 30 to 70 year old patients undergoing liver resection were incubated with 6.3 to 1,000 uM atrazine, terbuthylazine, terbutryne, or ametryne , and the incubation mixtures were analyzed for metabolites. The compounds produced a variety of metabolites indicative of S-oxidation, N-dealkylation, and side chain C-oxidation. The metabolites were formed by processes showing biphasic kinetics, Michaelis constants for the first and second phases varying from 1.4 to 20 uM and from 54 to 530 uM, respectively. Atrazine, terbuthylazine, ametryne, or terbutryne at 25 uM was incubated with human liver microsomes containing substrates for cytochrome-P4501A2 (CYP1A2), cytochrome-P4502A6, cytochrome-P4502D6, cytochrome-P4502C9, cytochrome-P4502C19, cytochrome-P4502E1, or cytochrome-P4503A4 (CYP3A4) isozymes. Other microsomal preparations were incubated with 25 or 600 uM of the S-triazines in the presence or absence of alpha-naphthoflavone (aNF), furafylline, quinidine, sulfaphenazole, diethyl-dithiocarbamate, gestodene, or ketoconazole, inhibitors of various specific cytochrome-P450 (P450) isozymes, at concentrations 5 to 10 times greater than their inhibition constants. Microsomal preparations containing substrates for CYP1A2 and CYP3A4 showed the best correlation with the rates of metabolism of the S-triazines. Only aNF and furafylline, inhibitors of CYP1A2, inhibited metabolism of the S-triazines. A human liver microsomal preparation with demonstrated high levels of flavin containing monooxygenase (FMO) activity and purified recombinant human FMO-3 were incubated with ametryne and terbutryne. The extent of sulfoxidation of the two compounds was determined. No significant formation of sulfoxide metabolites was detected, indicating that the FMO system was not involved in the metabolism of S- triazines by human liver microsomes. The authors conclude that these results clearly identify CYP1A2 as the major phase-I P450 isozyme that is involved in the

For more Metabolism/Metabolites (Complete) data for TERBUTRYNE (7 total), please visit the HSDB record page.

Terbutryn has known human metabolites that include 2-Hydroxyethylterbutryn, t-Butylhydroxy-terbutryn, and Terbutrynsulfoxide.

They are efficiently absorbed from intestine, and presumably there is some absorption across the skin and lung. /Urea-, uracil- and triazine-based herbicides/

Absorbed through both foliage and roots. It appears to penetrate foliage rapidly, minimizing removal from foliage by rain. /It is/ translocated acropetally through xylem from roots and foliage, accumulating in apical meristems.

In mammals, following oral admin, 73-85% is eliminated in metabolized form in feces within 24 hr.

Used as selective herbicide for control of annual broadleaf and grass weeds in cereals, sugar cane, maize, other crops, and fallow land; Also used to control algae and submerged plants in waterways, reservoirs, and fish ponds; [HSDB]

Cancelled--no longer registered as a pesticide for use in the US; [HSDB]

Farming (Pesticides) [Category: Industry]

The active ingredient is no longer contained in any registered pesticide products ... "cancelled."

For terbutryn (USEPA/OPP Pesticide Code: (080813) there are 0 labels match. /SRP: Not registered for current 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./

Selective herbicide for control of annual broadleaf & grass weeds in winter wheat, winter barley, sorghum ... (use for wheat is restricted to Washington, Oregon, Idaho, & Utah and use for barley is restricted to Washington, Oregon and Idaho). /Former use/

React 2-chloro-4-ethylamino-6-t-butylamino-1,3,5-triazine with methyl mercaptan in presence of equivalent of sodium hydroxide. Reacting 2-mercapto-4-ethylamino-6-t-butylamino-1,3,5-triazine with methylating agent in presence of sodium hydroxide.

Terbutryne may be made by reacting terbuthylazine ... with methyl mercaptan in the presence of an equivalent amount of caustic.

Terbutryn is produced by reaction of 2-chloro-4-ethylamino-4,6-butylamino-1,3,5-triazine with methyl mercaptan in the presence of sodium hydroxide.

'Igran' 50wp & 80wp, wettable powder (500 or 800 g active ingredient /kg); 'igram' 500fw, 'clarosan 500fw, prebane 500 fw, soluble concentrate (500 g/L) ...

Mixed formulations: (terbutryn +) linuron; ... metobromuron; ... neburon; MCPA + simazine: mecoprop + simazine.

MIXTURES INCLUDE: DICURAN EXTRA, TERBUTRYNE + CHLORTOLURON (1:6); GESAPRIM COMBI (REG NUMBER 8063-10-2), (TERBUTRYNE + ATRAZINE (1:1)); IGRATER (REG NUMBER 52080-96-3), (TERBUTRYNE + METOBROMURON (1:1)); LEXTRA (PAN BRITANNICA IND), (TERBUTRYN + TRIFLURALIN); OPOGARD, SORGOPRIM (1:1), TOPOGARD (7:3) (REG NO 8066-11-3), (TERBUTRYN + TERBUTHYLAZINE); PEAWEED (PAN BRITANNICA IND), (TERBUTRYN + PROMETRYN); PIOTAL, (TERBUTRYN + CHLOROTOLURON + TERBUTHYLAZINE (1:5:4); TEMPO (FARM PROTECTION), SC (150 G TERBUTRYN + 150 G LINURON/L).

Herbicides, Transformation products

Pesticides -> Herbicides -> Triazine herbicides -> Methylthiotriazine herbicides

Pharmaceuticals

HERBICIDES

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

Applications may be made preemergence or post-emergence in fall or early spring in winter wheat & postemergence in fall or early spring in winter barley. It may be applied preemergence, alone or with aatrex or milogard in grain sorghum. Applications can be made with ground & aerial equipment. ... /It is/ compatible with most other pesticides & fertilizers when used at normal rates.

Registration notes: Discontinued in USA.

/In 1995/ Terbutryn /was/ a General Use Pesticide (GUP). The U.S. Environmental Protection Agency had proposed the revocation of all tolerances for residues of terbutryn in or on barley, sorghum, and wheat. They /did/ not plan to recommend action levels to replace the tolerances (Federal Register 59(138):37019). Many terbutryn product registrations had been cancelled. The EPA has classified it as Toxicity Class III-slightly toxic. Products containing terbutryn bear the Signal Word "Caution".

For more General Manufacturing Information (Complete) data for TERBUTRYNE (6 total), please visit the HSDB record page.