Tribufos

314.511

314.51

201-120-8

53075G8GRF

2811|2902

DTXSID1024174

Colorless to pale yellow liquid

102.78000

3.23

S,s,s-tributyltrithiophosphate is a colorless to pale yellow liquid with mercaptan-like odor. Insoluble in water. Used as a growth regulator.

1.06 g/cm³ @ Temp: 20 °C

<-25 °C

150 °C @ Press: 0.3 Torr

200.4±24.0 °C

1.517

In water, 2.3 mg/L at 20 deg C

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.

5.3X10-6 mm Hg at 25 deg C

LD50 in male, female rats (mg/kg): 233, 150 orally; 360, 168 dermally (Gaines)

Mercaptan-like odor

2.94e-07 atm-m3/mole|Henry's Law constant = 2.94X10-7 atm-cu m/molc sec at 25 °C

Insoluble in water. Hydrolyzed slowly by alkaline conditions.

Esters, Sulfate Esters, Phosphate Esters, Thiophosphate Esters, and Borate Esters

An organophosphate derivative. Organophosphates are susceptible to formation of highly toxic and flammable phosphine gas in the presence of strong reducing agents such as hydrides. Partial oxidation by oxidizing agents may result in the release of toxic phosphorus oxides.

II

6.1(a)

UN 2811

R24/25

S45;S36/S37

T: Toxic;

Relatively stable to acids and heat. Hydrolysed slowly under alkaline conditions; DT50 (35 deg C) 14 days (pH 4.7 to 9). Photolysed slowly.

P273-P280-P301 + P310-P302 + P350-P310-P501

H301-H310-H410

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.|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.

USEPA/Office of Pesticide Programs; Interim Reregistration Eligibility Decision (IRED) for Tribufos. EPA issues an IRED for a pesticide that is undergoing reregistration, requires a reregistration eligibility decision, and also needs a cumulative assessment under FQPA. The IRED, issued after EPA completes the individual pesticide\'s aggregate risk assessment, may include taking risk reduction measures -- for example, reducing risks to workers or eliminating uses that the registrant no longer wishes to maintain -- to gain the benefits of these changes before the final RED can be issued following the Agency\'s consideration of cumulative risks.[Available from, as of February 7, 2006: http://www.epa.gov/pesticides/reregistration/status.htm]|USEPA, Gulf Breeze Environmental Research Lab. Acephate, Aldicarb, Carbophenthion, DEF, EPN, Ethoprop, Methyl Parathion, & Phorate: Their Acute & Chronic Toxicity, Bioconcentration Potential, & Persistance as Related to Marine Environments. EPA-600/4-81-041. (NTIS PB81-244477). May 1981.

Excerpt from ERG Guide 154 [Substances - Toxic and/or Corrosive (Non-Combustible)]: Non-combustible, substance itself does not burn but may decompose upon heating to produce corrosive and/or toxic fumes. Some are oxidizers and may ignite combustibles (wood, paper, oil, clothing, etc.). Contact with metals may evolve flammable hydrogen gas. Containers may explode when heated. For electric vehicles or equipment, ERG Guide 147 (lithium ion batteries) or ERG Guide 138 (sodium batteries) should also be consulted. (ERG, 2016)

|Danger|H301 (99.24%): Toxic if swallowed [Danger Acute toxicity, oral]|P262, P264, P270, P273, P280, P301+P310, P302+P350, P310, P321, P322, P330, P361, P363, P391, P405, and P501|Aggregated GHS information provided by 132 companies from 4 notifications to the ECHA C&L Inventory. Each notification may be associated with multiple companies.|H301: Toxic if swallowed [Danger Acute toxicity, oral]|P260, P261, P262, P264, P270, P271, P280, P301+P310, P302+P350, P304+P340, P310, P311, P314, P321, P322, P330, P361, P363, P403+P233, P405, and P501

Excerpt from ERG Guide 154 [Substances - Toxic and/or Corrosive (Non-Combustible)]: SMALL FIRE: Dry chemical, CO2 or water spray. LARGE FIRE: Dry chemical, CO2, alcohol-resistant foam or water spray. Move containers from fire area if you can do it without risk. Dike fire-control water for later disposal; do not scatter the material. FIRE INVOLVING TANKS OR CAR/TRAILER LOADS: Fight fire from maximum distance or use unmanned hose holders or monitor nozzles. Do not get water inside containers. 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 154 [Substances - Toxic and/or Corrosive (Non-Combustible)]: 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 154 [Substances - Toxic and/or Corrosive (Non-Combustible)]: ELIMINATE all ignition sources (no smoking, flares, sparks or flames in immediate area). Do not touch damaged containers or spilled material unless wearing appropriate protective clothing. Stop leak if you can do it without risk. Prevent entry into waterways, sewers, basements or confined areas. Absorb or cover with dry earth, sand or other non-combustible material and transfer to containers. DO NOT GET WATER INSIDE CONTAINERS. (ERG, 2016)

Excerpt from ERG Guide 154 [Substances - Toxic and/or Corrosive (Non-Combustible)]: Wear positive pressure self-contained breathing apparatus (SCBA). Wear chemical protective clothing that is specifically recommended by the manufacturer. It may provide little or no thermal protection. Structural firefighters' protective clothing provides limited protection in fire situations ONLY; it is not effective in spill situations where direct contact with the substance is possible. (ERG, 2016)

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.

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.|Indoor Applications. If the label directions permit, leave all windows open and fans operating after the application is completed. If the pesticide product is only effective in an unventilated (sealed) room or house, do not stay there. Put all pets outdoors, and take yourself any your family away from treated areas for at least the length of time prescribed on the label. Apply most surface sprays only to limited areas such as cracks; don't treat entire floors, walls, or ceilings. Don't let pesticides get on any surfaces that are used for food preparation. Wash any surfaces that may have pesticide residue before placing food on them.|Indoor Applications. When using total release foggers to control pests, use no more than the amount needed and to keep foggers away from ignition sources (ovens, stoves, air conditioners, space heaters, and water heaters, for example). Foggers should not be used in small, enclosed places such as closets and cabinets or under tables and counters.|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.

Tribufos is a colorless to pale yellow liquid with a skunk-like odor; it is used only as a defoliant (a chemical that removes leaves) for cotton plants. Removing the leaves keeps certain pests that may be found on the leaves from damaging the cotton before it is picked.

Tribufos was detected in various seed cotton and gin wastes collected from two fields in the San Joaquin Valley, CA, in 1977 at the following avg and max concn (2 and 4 sample modules each category for the 2 fields): 1.78-2.00 ppm avg, 2.39 ppm max in seed cotton; 2.21-3.00 ppm avg, 4.36 ppm max in lint; 0.18-0.24 ppm avg, 0.31 ppm max in seeds; 28.3-34 ppm avg, 43 ppm max in mote waste; 46-60 ppm avg, 81.7 ppm max in whole waste; 31.4-39.6 ppm avg, 47.8 ppm max in coarse fraction; and 93.7-96.8 ppm avg, 113 ppm max in fine fraction(1).

SOIL: In the National Soils Monitoring Program, tribufos was detected in 4 of 1,246 samples of soil (0.3% positive from 37 states at concn ranging from 0.06 to 0.67 ppm dry weight in 1972 (Fiscal Year 1973)(1); in 1971 (Fiscal Year 1972) it was found in 4 of 1,141 samples of soil (0.4% pos) from 37 states at concn ranging from 0.15 to 0.66 ppm(2). In 1972, 2 of the positive soil samples were from the 30 samples from MS (0.06 and 0.67 ppm), 1 of 27 samples from LA contained 0.08 ppm, and 1 of 64 samples from CA contained 0.10 ppm(1). In 1971, 3 of the positive soil samples were from the 31 samples from MS (0.15-0.66 ppm), and 1 of 106 samples from NE contained 0.03 ppm(2).

SOURCE DOMINATED: Tribufos was detected in air 50 m outside of a cotton field during treatment with the compound at an avg concn of 1189 ng/cu m; the concn detected after 24 and 72 hr were 450 and 24 ng/cu m, respectively(1). It was also detected in air 50 m outside the cotton field during treatment with the compound merphos at a max concn of 6080 ng/cu m(1). Ambient air samples from 10 residential areas of Kern County, CA, near cotton fields where tribufos and merphos were being sprayed contained concn of tribufos ranging from 2.7 to 87.4 ng/cu m; tribufos was detected at 2.7 ng/cu m in one of the 40 air samples from the 10 residential areas 2-weeks after application(2). Tribufos was found in 2 of 38 background samples taken from the 10 residential sites near cotton fields prior to the application period; concn were 3.6 and 5.4 ng/cu m(2).|URBAN/SUBURBAN: Tribufos was detected at a concn of 95 ng/cu m in 1 of 123 samples taken at 10 U.S. locations in Fiscal Year 1980(1). Interstitial air in fog at 2 of 4 sites contained concn ranging from <3X10-5 ng/L (Parlier, CA) to 1.4X10-4 ng/L (Corcoran, CA); it was not detected in samples of fog air from Lodi, CA and Beltsville, MD(2). Tribufos was detected in 10% of the air samples (0.04 ng/cu m max concn) collected at various sites along the Mississippi River from New Orleans, LA to St. Paul, MN during the first 10 days of 1994(3).|RURAL/REMOTE: Tribufos was detected in 12 of 98 samples of ambient air collected in 1967 and 1968 in rural areas Stoneville, MS; the max concn was 16 ng/cu m(1).

Tribufos was detected in domestic and imported animal feed at 0.025 ppm during the FDA food monitoring program in 2003; levels of 0.031 to 0.069 ppm (median concn 0.034 ppm)in the FDA food monitoring program in 2002; 0.030 to 0.150 ppm (median concn 0.074 ppm)in the FDA food monitoring program in 2001; 0.042 to 0.095 ppm (median concn 0.057 ppm)in the FDA food monitoring program in 2000; 0.038 to 0.095 ppm (median concn 0.055 ppm)in the FDA food monitoring program in 1999(1).

DEF at doses which had little effect on brain acetylcholinesterase, inhibited mouse and rat tissue carboxylesterases and potentiated acute toxic action of organophosphorus insecticides.|Effect of diazinon (0.002%) against female Lucilia cuprina was potentiated by prior treatment with 1% s,s,s-tributyl phosphorotrithioate.|DEF acted as synergist when used with endrin and methomyl against the Egyptian cotton leafworm Spodoptera littorals.|DEF synergized diflubenzuron and Bay Sir 8514 3319- and 45-fold, respectively, in Platynota stultana, but was not synergistic in Spodoptera exiqua.

LD50 Guinea pig male oral 260 mg/kg|LD50 Rabbit dermal 97 mg/kg|LD50 Mouse ip 290 mg/kg|LD50 Rat ip 210 mg/kg|For more Non-Human Toxicity Values (Complete) data for TRIBUFOS (11 total), please visit the HSDB record page.

/AQUATIC SPECIES/ Partial life cycle toxicity tests (90 days) were conducted to determine the effects of the organophosphorus defoilant S,S,S-tributyl phosphorotrithioate (DEF), on Rainbow trout (Salmo gairdneri) and Channel catfish (Ictalurus punctatus). Exposure concentrations were 0, 0.76, 1.2, 1.7, 2.7, 3.6, 6.5 and 9.5 ug/L for Rainbow trout and 0, 0.77, 2.0, 4.8, 10.0 and 19.6 ug/L for Channel catfish. In Rainbow trout growth was reduced by DEF concentrations greater than or equal to 1.2 and survival by concentrations greater than or equal to 3.6 ug/L; growth and survival of channel catfish were reduced by DEF concentrations greater than or equal to 4.8 and 19.6 ug/L, respectively. DEF adversely affected vertebral biochemical composition and mechanical properties of both species. DEF was not highly accumulative in the tissues of either species and was eliminated rapidly when the fish were transferred to contaminant-free water. The determination of safe environmental concentrations of DEF depends partly on the species tested and the biological response measured. Application factors classically used to estimate safe environmental concentrations of contaminants may not be applicable to some of the new-generation organophosphate compounds in relation to cold water species such as Rainbow trout.|/AQUATIC SPECIES/ The maximum acceptable toxicant concentrations (MATC) at lethal & sublethal concentrations to Dungeness crab were above 0.95 & below 6.9 ug/L for DEF.

S,S,S-Tributyl phosphorotrithioate's (Tribufos) production may result in its release to the environment through various waste streams; it's use as a defoliant for cotton crops(1) will result in its direct release to the environment(SRC). It is also formed in the environment as a result of the release of the defoliant, merphos (S,S,S-tributyl trithiophosphite), which is rapidly oxidized under environmental conditions to tribufos(2).

TERRESTRIAL FATE: Based on a classification scheme(1), Koc values of 4,870 to 12,684 measured in 4 soils(2),indicate that tribufos is expected to be immobile in soil(SRC). Volatilization of tribufos from moist soil surfaces is not expected to be an important fate process(SRC) given a Henry's Law constant of 2.9X10-7 atm-cu m/mole(3). Tribufos is not expected to volatilize from dry soil surfaces(SRC) based upon its vapor pressure of 5.3X10-6 mm Hg(4). Tribufos is very persistent in soils based on an aerobic biodegradation half-life of 745 days in a sandy loam, and an anaerobic biodegradation half-life of 389 days in the same soil(2).|AQUATIC FATE: Based on a classification scheme(1), Koc values of 4,870 to 12,684(2), indicate that tribufos 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 2.9X10-7 atm-cu m/mole(4). According to a classification scheme(5), BCF values of 300 to 1,300 measured in fish(2), suggest bioconcentration in aquatic organisms is high to very high(SRC). Tribufos is stable to hydrolysis at pH 5 and 7; however, the half-life at pH 9 was 124 days(2). Photolysis in sunlit surface waters does not appear to be an important environmental fate process(2). Tribufos degrades slowly in aquatic systems, with half-lives of about 120 to 180 days measured in pond sediment(2).|ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), tribufos, which has a vapor pressure of 5.3X10-6 mm Hg at 25 °C(2), is expected to exist in both the vapor and particulate phases in the ambient atmosphere. Vapor-phase tribufos 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 5 hours(SRC), calculated from its rate constant of 7.9X10-11 cu cm/molecule-sec at 25 °C(SRC) that was derived using a structure estimation method(3).

The rate constant for the vapor-phase reaction of tribufos with photochemically-produced hydroxyl radicals has been estimated as 7.9X10-11 cu cm/molecule-sec at 25 °C(SRC) using a structure estimation method(1). This corresponds to an atmospheric half-life of about 5 hours at an atmospheric concentration of 5X10+5 hydroxyl radicals per cu cm(1).|Tribufos exhibited a slow rate of breakdown in laboratory studies when irradiated with artificial light at wavelengths >290 nm in air containing an unspecified concn of ozone; the reaction was too slow to be observed in field studies using the spray drift technique(1). Since tribufos absorbs light at wavelengths >290 nm(2), direct photolysis may be possible in the atmosphere and surface waters(SRC). In experiments studying the persistence of the pesticide merphos (S,S,S-tributyl trithiophosphite) conducted in water from the Little Miami River in sealed glass jars exposed to sunlight and artificial fluorescent light, the amount of tribufos (formed in an apparently quantitative yield from merphos within 1 hr) recovered was 50%, 30%, 10% and <5% after 1, 2, 4 and 8 weeks, respectively(3). The study did not determine whether the observed degradation of tribufos was due to abiotic processes (such as photolysis or hydrolysis) or biological processes(3). Tribufos was reported to be stable when 1 mg/L sterilized solutions were irradiated with light from a xenon arc lamp (310-740 nm) over a 30 day irradiation period(4). Tribufos was stable at pH 5 and 7 at 24 °C, but had a hydrolysis half-life of 124 days at pH 9 and 24 °C(4).

A BCF of 350 was determined for pinfish (Lagodon rhomboides) in a 96-hr static experiment, but the investigators concluded that the value was a low estimate of the true BCF because the experiment was not run for a long enough time for equilibrium to be reached(1). BCF values of 300, 1,300, and 730 were reported for the edible, viscera, and whole body, respectively of bluegill sunfish exposed to 0.0062 mg/L of tribufos for 14 days(2). According to a classification scheme(3), these BCF values suggest bioconcentration in aquatic organisms is high to very high(SRC).

5.01e+03 L/kg|Koc values of 9,115, 12,684, 10,465, and 4,870 were reported for tribufos in a clay loam, sand, sandy loam, and silt loam, respectively(1). According to a classification scheme(4), these Koc values suggests that tribufos is expected to be immobile in soil(SRC).

The Henry's Law constant for tribufos is 2.9X10-7 atm-cu m/mole(1). This Henry's Law constant indicates that tribufos is expected to essentially be non-volatile from water and moist soil surfaces(2). Tribufos is not expected to volatilize from dry soil surfaces(SRC) based upon its vapor pressure of 5.3X10-6 mm Hg at 25 °C(3). Evaporation losses of tribufos (as measured by the amount found in an exiting-air trap) were observed to be 12% after 7 days in a laboratory experiment utilizing 1 ug of tribufos in 100 mL of seawater that was aerated at a rate of 50 mL/min in a 150 mL centrifuge tube(4). No volatilization losses were observed in the above experiment when 10 g (wet wt) of sediment were added to the tubes(4).

DRINKING WATER: Tribufos was identified, not quantified, in unspecified samples of Japanese raw and finished drinking water derived from rivers under the influence of agriculture and industry at almost the same unspecified parts/trillion concentration throughout the year(1).|GROUNDWATER: One verified detection of tribufos was made in samples of groundwater from 28 of California's 58 counties tested through Nov 1984(1). It was detected at 1 sample from an unspecified number of samples of groundwater taken in CA at a concn of 1.7 ug/L(2).|RAIN/SNOW: Fogwater at 2 of 4 sites contained terbufos at concentrations ranging from 250 ng/L (Parlier, CA) to 800 ng/L (Corcoran, CA); it was not detected in samples of fogwater from Lodi, CA and Beltsville, MD(1).

In the FDA Adult Total Diet studies for Oct 1980 to March 1982, tribufos was detected in 1 sample of an unspecified number of samples of potatoes; no detections were made in (Fiscal Year 1978) nor in any of the foods from the other 12 food groups tested(1). In the FDA study for Oct 1978 to Sept 1979 (Fiscal Year 1979), tribufos was detected in 1 sample of an unspecified number of samples of potatoes at 0.002 ppm; no detections were made in any of the foods from the other 12 food groups tested(2). In FDA studies conducted between Fiscal Years 1982 and 1986, tribufos was detected in 2 of 6,391 samples of U.S. domestic agricultural commodities at a concn of 0.10-0.50 and >2.0 ppm in the 2 samples; it was not detected in 1,239 imported agricultural commodities(3). Tribufos was identified, not quantified, in unspecified food items in the FDA 1999 Pesticide Monitoring program(4). It was not detected in any food items during the 2000 to 2003 monitoring years(4).

The metabolism and residue levels of the defoliant S,S,S-tributyl-phosphorotrithioate (78488) (DEF) were investigated in urine, selected tissue, and milk from a French-Alpine-goat. ... The main route of excretion for the DEF metabolites was the urinary tract, accounting for 52% of the total dose. Fecal excretion accounted for 13% of the total dose. ... The total radioactive residue in fat and milk was composed 31% and 5% respectively of DEF. Less than 1% of the total radioactive residue was contained in the DEF found in the liver, kidney and muscle. The tissue, milk, and urine contained 3-hydroxybutylmethyl-sulfone, a major metabolite. Two minor components of the urine were S,S-dibutyl-phosphorodithioate and S-butyl-phosphorothioate.

NIOSH (NOES Survey 1981-1983) has statistically estimated that 3,110 workers are potentially exposed to tribufos in the USA(1). The NOES Survey does not include farm workers. Occupational exposure to tribufos may occur through inhalation of dusts or dermal contact with this compound at workplaces where it is produced or used(SRC). The greatest potential for dermal and inhalation exposure to tribufos is expected for applicators and farm workers that have frequent contact with this compound when used as a defoliant for cotton crops. Monitoring data indicate that the general population may be exposed to tribufos via inhalation of ambient air and ingestion of food(SRC).|Air samples collected adjacent to two operations with cotton gin waste contained the following concns of tribufos (ng/cu m): screening process, prescreening 5.0 and 9.0 by XAD-4 resin and glass fiber filter analytical methods, respectively; during screening, 6-31 and 220-340, respectively; precomposting, 3.0 and 0.66, respectively; and during turning of compost, <2.0-6.0 and <0.10-1.0, respectively(1). Tribufos was detected in high volume air samples using an air filter and a resin analytical method for various work sites at a cotton farm(2). The concns at various job stations were as follows (ng/cu m): flagger 5,434-80,790 by filter, 58.6-2,409 by resin; mixer/loader, 115-933 and 19.1-265; cotton gin, 7.0-17.8 and not detected(2). Personal air samples for workers at the cotton farm contained the following tribufos levels (ug/cu m): outside harvester cab 539-13,305; inside harvester cab, 147-882; cockpit of spray aircraft, 784-6,961; flagger, 7,353-13,529(2). Cloth patches on workers at the cotton fields contained the following ranges of tribufos (ng/sq cm): flagger (0.8-7 hr sampling time), 85-224; mixer/loader (1-7 hr), 23-131; harvester operator (1-3 hr), 3-96; tramper (4 hr), 20-60; ginner (3 hr), trace; pressman (3 hr), trace-5; and janitor (3 hr), trace-5(2).

Herbicides that remove leaves from trees and growing plants. They may be either organic or inorganic. Several of the more persistent types have been used in military operations and many are toxic. (From Hawley's Condensed Chemical Dictionary, 11th ed) (See all compounds classified as Defoliants, Chemical.)|Chemicals that, while not possessing inherent pesticidal activity, nonetheless promote or enhance the effectiveness of other pesticides when combined. (See all compounds classified as Pesticide Synergists.)|Compounds or agents that combine with an enzyme in such a manner as to prevent the normal substrate-enzyme combination and the catalytic reaction. (See all compounds classified as Enzyme Inhibitors.)

Tribufos is rapidly absorbed and metabolised /in animals/; 96% of the administered radioactivity was excreted within 72 hours.

/In animals/ metabolism proceeds by hydrolysis followed by methylation and successive oxidation of butylmercaptan, yielding the main metabolite (3-hydroxy)-butylmethylsulfone.|The data presented here indicate that rodents metabolize and excrete delayed neurotoxic organophosphorus esters with great efficiency. By contrast, the adult chicken seems to have difficulty carrying out these processes. The cat is intermediate between rodents and chickens. Although further studies are needed, these results suggest that the hen model may exaggerate the effect of neurotoxic organophosphorus esters. Extrapolation of findings from the chicken may thus overestimate the risk or hazard of organophosphorus esters to humans. This may explain why no human case of O-ethyl-O-nitrophenyl phenylphosphonothioate induced delayed neurotoxicity has been reported despite the fact that it has been in use for over a quarter of a century. Other neurotoxicity data from our laboratory seem to support the suggestion that the cat may be a better model to extrapolate neurotoxicity results to humans. The data presented in this review suggest that the phrmacokinetics and metabolism of organophosphorus esters may play a prominent role in species and age sensitivities for organophosphorus-induced delayed neurotoxicity. Animals that are sensitive to delayed neurotoxicity have a higher accumulation rate, coupled with slower elimination of the neurotoxic agent. These studies, however, do not rule out the possibility that the target tissue of organophosphorus delayed neurotoxicity itself is species or age specific.|The metabolism and residue levels of the defoliant S,S,S-tributyl-phosphorotrithioate (78488) (DEF) were investigated in urine, selected tissue, and milk from a French-Alpine-goat. ... The main route of excretion for the DEF metabolites was the urinary tract, accounting for 52% of the total dose. Fecal excretion accounted for 13% of the total dose. ... The total radioactive residue in fat and milk was composed 31% and 5% respectively of DEF. Less than 1% of the total radioactive residue was contained in the DEF found in the liver, kidney and muscle. The tissue, milk, and urine contained 3-hydroxybutylmethyl-sulfone, a major metabolite. Two minor components of the urine were S,S-dibutyl-phosphorodithioate and S-butyl-phosphorothioate.

Excerpt from ERG Guide 154 [Substances - Toxic and/or Corrosive (Non-Combustible)]: TOXIC; inhalation, ingestion or skin contact with material may cause severe injury or death. Contact with molten substance may cause severe burns to skin and eyes. Avoid any skin contact. Effects of contact or inhalation may be delayed. Fire may produce irritating, corrosive and/or toxic gases. Runoff from fire control or dilution water may be corrosive and/or toxic and cause pollution. (ERG, 2016)

Excerpt from ERG Guide 154 [Substances - Toxic and/or Corrosive (Non-Combustible)]: 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. Do not use mouth-to-mouth method if victim ingested or inhaled the substance; give artificial respiration with the aid of a pocket mask equipped with a one-way valve or other proper respiratory medical device. 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. For minor skin contact, avoid spreading material on unaffected skin. Keep victim calm and warm. Effects of exposure (inhalation, ingestion or skin contact) to substance may be delayed. (ERG, 2016)

Airway protection. Insure that a clear airway exists. Intubate the patients and aspirate the secretions with a large-bore suction device if necessary. Administer oxygen by mechanically assisted pulmonary ventilation if respiration is depressed. Improve tissue oxygenation as much as possible before administering atropine, so as to minimize the risk of ventricular fibrillation. In severe poisonings, it may be necessary to support pulmonary ventilation mechanically for several days. /Organophosphate pesticides/|Atropine sulfate. Administer atropine sulfate intravenously, or intramuscularly if intravenous injection is not possible. Remember that atropine can be administered through an endotracheal tube if initial IV access if difficult to obtain. ... Atropine does not reactivate the cholinesterase enzyme or accelerate disposition of organophosphate. Recrudescence of poisoning may occur if tissue concentrations of organophosphate remain high when the effect of atropine wears off. Atropine is effective against muscarinic manifestations, but it is ineffective against nicotinic actions, specifically muscle weakness and twitching, and respiratory depression. Despite the limitations, atropine is often a life-saving agent in organophosphate poisonings. ... The adjunctive use of nebulized atropine has been reported to improve respiratory distress, decrease bronchial secretions, and increase oxygenation. /Organophosphate pesticides/|Glycopyrolate has been studied as an alternative to atropine and found to have similar outcomes using continuous infusion. Ampules of ... glycopyrolate were added to ... saline and this infusion was titrated to the desired effects of dry mucous membranes and heart rate above 60 beats/min. During this study, atropine was used as a bolus for a heart rate less than 60 beats/min. The other apparent advantage to this regimen was a decreased number of respiratory infections. ... /Organophosphate pesticides/|Pralidoxime. Before administration of pralidoxime, draw a blood sample (heparinized) for cholinesterase analysis (since pralidoxime tends to reverse the cholinesterase depression). Administer pralidoxime (Protopam, 2-PAM), a cholinesterase reactivator, in cases of severe poisoning by organophosphate pesticides in which respiratory depression, muscle weakness, and/or twitching are severe. When administered early (usually less than 48 hours after poisoning) pralidoxime relieves the nicotinic as well as the muscarinic effects of poisoning. Pralidoxime works by reactivating the cholinesterase and also by slowing the "aging" process of phosphorylated cholinesterase to a non-reactivatable form. ... Dosage of pralidoxime may be repeated in 1-2 hours, then at 10-12 hour intervals if needed. In very severe poisonings, dosage rates may be doubled. Repeated doses of pralidoxime are usually required. In cases that involve continuing absorption of organophosphate (as after ingestion of large amounts), or continuing transfer of highly lipophilic organophosphate from fat into blood, it may be necessary to continue administration of pralidoxime for several days beyond the 48 hour post-exposure interval usually cited as the limit of its effectiveness. ... Blood pressure should be monitored during administration because of the occasional occurrence of hypertensive crisis. Administration should be slowed or stopped if blood pressure rises to hazardous levels. Be prepared to assist pulmonary ventilation mechanically if respiration is depressed during or after pralidoxime administration. If intravenous injection is not possible, pralidoxime may be given by deep intramuscular injection. /Organophosphate pesticides/|For more Antidote and Emergency Treatment (Complete) data for TRIBUFOS (11 total), please visit the HSDB record page.

/SIGNS AND SYMPTOMS/ SYMPTOMATOLOGY: Nausea, ... vomiting, abdominal cramps, diarrhea, excessive salivation ... . Headache, giddiness, vertigo & weakness. Rhinorrhea & sensation of tightness in chest are common in inhalation exposure. Blurring or dimness of vision, miosis, ... tearing, ciliary muscle spasm, loss of accommodation & ocular pain, ... mydriasis ... sometimes seen ... probably due to sympatho-adrenal discharge. Loss of muscle coordination, slurring of speech, fasciculations and twitching of muscles (particularly of tongue & eyelids), and generalized profound weakness. Mental confusion, disorientation & drowsiness. ... Difficulty in breathing, excessive secretion of saliva & of respiratory tract mucus, oronasal frothing, cyanosis, pulmonary rales & rhonchi & hypertension, (presumably due to asphyxia). Random jerky movements, incontinence, convulsions, & coma. Death primarily due to respiratory arrest arising from failure of respiratory center, paralysis of respiratory muscles, intense bronchoconstriction or all three.|/SIGNS AND SYMPTOMS/ ...Symptoms which had been reported by the 322 residents living in the cotton agricultural area during the 1987 cotton defoliation season were compared with symptoms reported by 175 residents in the areas where cotton is not grown. Respondents living or working near sprayed cotton fields reported fatigue, eye irritation, rhinitis, throat irritation, nausea, and diarrhea 60 to 100% more frequently than the comparison group.|/BIOMONITORING/ Inhibition of the neurotoxic esterase in lymphocytes /due to DEF and merphos/ was measured in 7 workers exposed during aerial and ground application of these defoliants in cotton fields, as was peripheral nerve function. The major route of exposure was via the skin. Lymphocyte neurotoxic esterase was affected in exposed workers, according to both intensity and length of exposure. There were no detectable electrophysiological effects. Measurement of neurotoxic esterase in lymphocytes in workers exposed to organophosphates is a rational biomonitor of delayed neuropathy.|/BIOMONITORING/ During the period of cotton crop treatment with methyl mercaptophos /SRP: precursor of s,s,s-tributyl phosphorotrithioate/, most of 33 teenagers from a rural area showed a 28% decrease in blood cholinesterase activity; 9 subjects from this group had a 50% enzyme level decrease. During defoliation treatment with butyphos (DEF) 31 of 33 subjects in the same group showed a 12% blood cholinesterase decrease. Blood cholinesterase dropped 28.6% in workers who were occupationally exposed to these organophosphorus pesticides ... Determination of blood cholinesterase levels in different population groups can be used as an index in the exploration of air contamination with organophosphorus pesticides.|For more Human Toxicity Excerpts (Complete) data for TRIBUFOS (6 total), please visit the HSDB record page.

butifos

Gastrointestinal (Stomach and Intestines, part of the digestive system), Neurological (Nervous System)

99% AS A DEFOLIANT ON COTTON; 1% AS A DEFOLIANT ON OTHER FIELD CROPS (1971)

Spray concentrate (700 g active ingredient/L).|Selected products: DEF 6, Folex. Discontinued products: Def, De-Green, E-Z-off D.|There are two technical products of tribufos presently registered. One technical (98.0% ai, liquid) is registered to Bayer (EPA Reg. No. 3125-96) and one to Micro Flo Company (98.1% ai with an EPA Reg. No. 51036-324). There are three liquid end-use products: one registered to Bayer (EPA Reg. No. 3125-282 - 71.5% ai); one registered to Aventis Crop Science (EPA Reg. No. 264-498 - 70.5% ai); and one registered to Micro Flo (EPA Reg. No. 51036-320 -70.5% ai). There was also one Special Local Need (SLN) product registered in Texas, (SLN No. TX810045) which Bayer requested cancellation on July 24, 2000.|Emulsifiable concentrate|For more Formulations/Preparations (Complete) data for TRIBUFOS (8 total), please visit the HSDB record page.

Pesticide, fertilizer, and other agricultural chemical manufacturing|Phosphorotrithioic acid, S,S,S-tributyl ester: ACTIVE|For complete defoliation 1.25-2.0 kg active ingredient/hectare, for bottom defoliation 1-1.5 kg/hectare|Very phytotoxic.|Application rates vary from 0.50 lbs ai/acre (tank-mixed) to 1.875 lbs ai/acre (tribufos used alone). Tribufos is most typically used in a tank-mix with other defoliants at a rate between 0.50 lbs ai/acre to 0.75 lbs ai/acre.|It was first registered in the United States in 1961.

... RESIDUES IN COTTON SEED MAY BE ASSAYED BY GLC.|METHOD DESCRIBED FOR DETERMINATION OF DEF AS LOW AS 200 PPT IN WATER. EXTRACTS ARE SUBJECTED TO GEL PERMEATION CHROMATOGRAPHY & SILICA GEL CHROMATOGRAPHY & ANALYSIS PERFORMED BY GAS CHROMATOGRAPHY WITH ELECTRON CAPTURE OR THERMIONIC DETECTORS.|Method: USGS-NWQL O-1402-01; Procedure: gas chromatography; Analyte: tribuphos; Matrix: filtered water; Detection Limit: 0.01 ug/L.|Method: USGS-NWQL O-5404-02; Procedure: high-performance gel-permeation chromatography, gas chromatography; Analyte: tribuphos; Matrix: bed-sediment (lake and stream), aqueous suspended-sediment, and soil samples; Detection Limit: 0.868 ug/kg.|Method: USGS-NWQL O-3402-03; Procedure: gas chromatography; Analyte: tribuphos; Matrix: whole-water samples; Detection Limit: 0.0041 ug/L.

METHOD DESCRIBED FOR DETERMINATION OF DEF AS LOW AS 5 PPB IN FISH. EXTRACTS ARE SUBJECTED TO GEL PERMEATION CHROMATOGRAPHY & SILICA GEL CHROMATOGRAPHY & ANALYSIS PERFORMED BY GAS CHROMATOGRAPHY WITH ELECTRON CAPTURE OR THERMIONIC DETECTORS.

Agrochemicals -> Plant Growth Regulators|DEFOLIANTS