Trichlorophenoxyacetic acid

Pesticide -> EPA IRIS

Herbicides

Active substance -> EU Pesticides database: Not approved

Pesticides -> Herbicides, Chlorophenoxy

Pesticide (2,4,5-T) -> USDA PDB

Pesticide

log Kow= 4

4

3.31

Odorless

Odorless.

1.803 at 68 °F (USCG, 1999) - Denser than water; will sink

SP GR: 1.80 AT 20 °C/20 °C

1.80 g/cm³

1.8

1.80 @ 20°C

1.80

WHITE SOLID

LIGHT TAN SOLID

Colorless to tan crystalline solid.

less than 0.1 mg/mL at 69.8 °F (NTP, 1992)

0.028% AT 25 °C

VERY SLIGHTLY SOL IN PETROLEUM ETHER

590 MG/KG IN ETHANOL OR ISOPROPYL ALC

1.05 x 10(-3) M at 25 °C

For more Solubility (Complete) data for 2,4,5-T (6 total), please visit the HSDB record page.

Decomposes (NTP, 1992)

Decomposes

No boiling point at normal pressure; decomposes on heating

decomposes

Decomposes

Toxic gases and vapors /which include/: hydrogen chloride and carbon monoxide.

When heated to decomp it emits toxic fumes of /hydrogen chloride/.

316 °F (NTP, 1992)

153 °C

153-158 °C

316 °F

153 °C

307 °F

Warning

H302: Harmful if swallowed [Warning Acute toxicity, oral]

P261, P264, P264+P265, P270, P271, P273, P280, P301+P317, P302+P352, P304+P340, P305+P351+P338, P319, P321, P330, P332+P317, P337+P317, P362+P364, P391, P403+P233, P405, and P501 (click each P-code to see the statement)

Warning

H302 (97.7%): Harmful if swallowed [Warning Acute toxicity, oral]

P261, P264, P264+P265, P270, P271, P273, P280, P301+P317, P302+P352, P304+P340, P305+P351+P338, P319, P321, P330, P332+P317, P337+P317, P362+P364, P391, P403+P233, P405, and P501 (click each P-code to see the statement)

2002/2076

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

Special Hazards of Combustion Products: Toxic hydrogen chloride and phosgene gases may be formed. (USCG, 1999)

Combustible under specific conditions. Liquid formulations containing organic solvents may be flammable. Gives off irritating or toxic fumes (or gases) in a fire.

2,4,5-T is toxic to the liver in acute animal studies. Epidemiology studies found no evidence that 2,4,5-T is teratogenic to exposed workers. [ACGIH] There is limited positive evidence that 2,4,5-T causes birth defects in animals. There is strong negative data that it causes skeletal defects in humans. [ATSDR Case Studies #29] Overall, it appears that the chlorophenoxy herbicides have led to little or no hepatic injury. Where sufficient occupational exposure seems to have led to hepatic abnormalities (e.g., toxic porphyria), the presumed chemical culprit has been the contaminating TCDD, rather than the herbicide per se. [Zimmerman, p. 415] In poisoning cases by ingestion of chlorophenoxy compounds, elevated liver enzymes and rhabdomyolysis with secondary renal failure have been reported; [HSDB]

FOREST PESTICIDES: AN OVERVIEW; ENVIRON SCI TECH 14 (10): 1165 (1980). DISCUSSES PROS & CONS OF USES OF 2,4,5-T IN FOREST, TCDD, HEALTH EFFECTS OF 2,4,5-T, THE VIETNAM EXPERIENCE, EPA'S ALSEA I & ALSEA II STUDIES & CRITIQUES, ETC.

FIRESTONE D; ECOL BULL 27: 39-52 (1978). A REVIEW ARTICLE DISCUSSES PROBLEMS & ADVERSE EFFECTS OF 2,3,7,8-TETRACHLORODIBENZO-P-DIOXIN, A CONTAMINANT OF HERBICIDE 2,4,5-T.

LACEY P, LACEY VA; J LEG MED (CHICAGO) 3 (1): 137-78 (1982). GOVERNMENT RESPONSIBILITY FOR MILITARY USE OF PHENOXY HERBICIDES.

HAY A; THE CHEMICAL SCYTHE: LESSONS OF 2,4,5-T AND DIOXIN, 264 PP (1982). A BOOK CONCERNING 2,4,5-T AND DIOXIN.

For more Special Reports (Complete) data for 2,4,5-T (12 total), please visit the HSDB record page.

Fire Extinguishing Agents: Water, foam, dry chemical, carbon dioxide (USCG, 1999)

Use water spray, powder.

Fresh air, rest.

Remove contaminated clothes. Rinse and then wash skin with water and soap.

First rinse with plenty of water for several minutes (remove contact lenses if easily possible), then refer for medical attention.

Rinse mouth. Give a slurry of activated charcoal in water to drink. Refer for medical attention .

EYES: First check the victim for contact lenses and remove if present. Flush victim's eyes with water or normal saline solution for 20 to 30 minutes while simultaneously calling a hospital or poison control center. Do not put any ointments, oils, or medication in the victim's eyes without specific instructions from a physician. IMMEDIATELY transport the victim after flushing eyes to a hospital even if no symptoms (such as redness or irritation) develop.

(General first aid procedures)

TIH (Toxic Inhalation Hazard) - Term used to describe gases and volatile liquids that are toxic when inhaled. Some are TIH materials themselves, e.g., chlorine, and some release TIH gases when spilled in water, e.g., chlorosilanes. [ERG 2016].

2.0 [mg/m3], inhalable fraction[German Research Foundation (DFG)]

/Wear/ self-contained breathing apparatus with a full facepiece operated in pressure-demand or other positive pressure mode /when fighting fire/.

Extinguish fire using agent suitable for type of surrounding fire.

1. VENTILATE AREA OF SPILL. 2. COLLECT SPILLED MATERIAL IN THE MOST CONVENIENT AND SAFE MANNER AND DEPOSIT IN SEALED CONTAINERS FOR RECLAMATION, OR FOR DISPOSAL IN A SECURED SANITARY LANDFILL. LIQUID CONTAINING 2,4,5-T SHOULD BE ABSORBED IN VERMICULITE, DRY SAND, EARTH, OR A SIMILAR MATERIAL.

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.

Water spill: Remove trapped material with suction hoses. If dissolved, in region of 10 ppm or greater concentration, apply activated carbon at ten times the spilled amount. Use mechanical dredges or lifts to remove immobilized masses of pollutants and precipitates.

Generators of waste (equal to or greater than 100 kg/mo) containing this contaminant, EPA hazardous waste numbers F027 & U232, must conform with USEPA regulations in storage, transportation, treatment and disposal of waste.

Chemical treatment: 2,4,5-T /2,4,5-trichlorophenoxyacetic acid/ is cleaved by strong acid to 2,4,5-trichlorophenol, formaldehyde and carbon dioxide. Glycollic acid appears to be an intermediate. This hydrolysis requires heating with concentrated acid or pyridine hydrochloride. 2,4,5-T is completely degraded by alkali metals (sodium or lithium) in liquid ammonia, but the degradation products have not been identified. Chlorination is capable of destroying 2,4,5-T. Aqueous hypochlorite at pH 3 and temp above 30 °C will yield herbicidally inactive products, but the products have not been characterized. At high temp (about 400 °C) chlorinolysis can degrade 2,4,5-T to a mixture of carbon tetrachloride, phosgene, and hydrogen chloride. None of these reactions are practical detoxification approaches for 2,4,5-T. Chemical treatment is not considered a viable approach for degrading the trace quantities of TCDD /2,3,7,8-tetrachlorodibenzo-p-dioxin/. Cleavage of the ether and dechlorination requires highly reactive chemical reagents, such as strong acid or sodium amide. Both 2,4,5-T and 2,3,7,8-tetrachlorodibenzo-p-dioxin are degraded by photochemical reactions. 2,4,5-T is detoxified by microbial activity in a period of 45 to 270 days. The biodegradation is most rapid in warm, aerated, moist soils, and aerobic activity is preferred. 2,3,7,8-tetrachlorodibenzo-p-dioxin is relatively persistent in soil. Approx 60% was recovered after 1-100 ppm 2,3,7,8-tetrachlorodibenzo-p-dioxin was incubated for one year in loamy sand or silty clay loam. It would appear that 2,3,7,8-tetrachlorodibenza-p-dioxin could build up in soil if 2,4,5-T containing trace amounts of 2,3,7,8-tetrachlorodibenzo-p-dioxin were disposed by land burial. In summary, no practical chemical detoxification procedures are now available for waste 2,4,5-T. The photochemical degradation to remove traces of 2,3,7,8-tetrachlorodibenzo-p- dioxin is an interesting approach for spill clean-up but not for disposal.

2,4,5-T (Weedon TM) 20% active ingredient was incinerated in a municipal multiple hearth sewage sludge incinerator with a temperature range of 457-940 °C with 6-10% excess air, the destruction efficiency was 99.980-99.996%. /From table, residence time not specified/

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/

For more Disposal Methods (Complete) data for 2,4,5-T (8 total), please visit the HSDB record page.

Personal protection: particulate filter respirator adapted to the airborne concentration of the substance. Do NOT let this chemical enter the environment. Sweep spilled substance into covered containers. If appropriate, moisten first to prevent dusting. Carefully collect remainder. Then store and dispose of according to local regulations.

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 action on skin, eyes, and respiratory tract and the continuous intake of small amounts. Very important to avoid drifting of spray clouds. Keep away from food, feeds, and water.

Persons not wearing protective equipment should be restricted from areas of spills until cleanup has been completed.

Good industrial practices recommend that engineering controls be used to reduce environmental concentrations to the permissible exposure level. However, there are some exceptions where respirators may be used to control exposure. Respirators may be used when engineering and work practice controls are not technically feasible, when such controls are in the process of being installed, or when they fail and need to be supplemented.

For more Preventive Measures (Complete) data for 2,4,5-T (7 total), please visit the HSDB record page.

During a week of exposed work and for 36 hours after exposure, levels of 2,4,5-T in urine of 4 ground spray applicators ranged from 1 to 11 ug/ml, the mean value was 3.5 ug/ml and the mean 24 hour excretion in urine was approximately 1 mg(1).

... The effects of 2,4,5-T were enhanced when 5,5,5-tributyl phosphotrithiolate was applied to four woody species of plants.

2,4,5-Trichlorophenoxyacetic acid (2,4,5-T) reduced the uptake of 5-hydroxy-3-indoleacetic acid (5-HIAA) by the choroid plexus in a dose-related manner, while treatment with quinolinic acid at comparable concentrations did not inhibit 5-HIAA uptake. The role of carrier-mediated transport in the clearance of 5-HIAA from cerebrospinal fluid (CSF) was also evaluated in vivo by ventriculocisternal perfusion. Steady-state clearance of 5-HIAA from CSF exceeded that of inulin and was reduced competitively in the presence of 2,4,5-T. However, the clearance was not affected by quinolinic acid. The effect of 2,4,5-T on transport enzyme system was also studied by electron microscopic cytochemistry. Na+-K+-ATPse and cytochrome oxidase activities in the choroid plexu were reduced by 2,4,5-T. Since this transport sytem in the choroid plexus is normally responsible for the excretion of the serotonin metabolite from the brain to the plasm, accumulation of endogenously produced orgnic acids in the CSF and the brain, secondary to reduce clearance by the choroid plexus, could be a contributing factor in the development of neurotoxicity.

2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) on hepatic metabolism of 2,4,5-trichlorophenoxyacetic acid (2,4,5-T) ... was studied in rats. Male Sprague-Dawley rats were injected with 0 or 31.5 ug/kg TCDD. 48 Hr later their livers were perfused in-situ for 1 hr by a recirculating system that contained 0 or 50 uM (14)C labeled 2,4,5-T ... . The livers were then removed and homogenized, and the extent of covalent binding of (14)C activity to macromolecules in the homogenates was determined. Samples of the bile and perfusate were analyzed for metabolites utilizing high pressure liquid chromatography. The perfusates from control and TCDD treated livers showed similar metabolic profiles with large amounts of unmetabolized 2,4,5-T ... as well as conjugates of 2,4,5-T with taurine ... . Bile samples from unpretreated and TCDD induced livers contained unmetabolized 2,4,5-T and conjugates of 2,4,5-T with glucuronic acid, glycine and taurine, and an unidentified metabolite. The unidentified metabolite accounted for 5.5 to 7.0% of the total 2,4,5-T in the bile and 1 percent of the total 2,4,5-T in the perfusate. Slightly more covalent binding of 2,4,5-T ... derived (14)C activity to hepatic macromolecule was seen in livers from control rats than from those pretreated with TCDD. ... /It was concluded/ that TCDD pretreatment does not enhance the short or long term toxicity of ... 2,4,5-T, and that until the structure of the unknown metabolite is identified and its potential effects determined, the exact role of TCDD in potentiating the toxicity of phenoxy acid herbicides remains unknown.

Urinary

Skin, liver, gastrointestinal tract

Exposure to large amounts of CDDs causes chloracne, a severe skin disease with acne-like lesions that occur mainly on the face and upper body. CDDs may also cause liver damage and induce long-term alterations in glucose metabolism and subtle changes in hormonal levels. In addition, studies have shown that CDDs may disrupt the endocrine system and weaken the immune system, as well as cause reproductive damage and birth defects, central and peripheral nervous system pathology, thyroid disorders, endometriosis, and diabetes. 2,3,7,8-Tetrachlorodibenzo-p-dioxin is also a known human carcinogen. (L177, L178)

LC50 Salmo gairdneri (rainbow trout) 350 mg/l/96 hr /Conditions of bioassay not given/

LC50 Lepomis macrochirus (bluegill) 0.50 mg/l/48 hr /Conditions of bioassay not specified/

LC50 Lebistes reticulatus (guppy) 8 mg/l/48 hr /Conditions of bioassay not specified/

LC50 Salmo gairdneri (rainbow trout) 1.3 mg/l/48 hr /Conditions of bioassay not specified/

For more Ecotoxicity Values (Complete) data for 2,4,5-T (21 total), please visit the HSDB record page.

TERRESTRIAL FATE: FOUR (14)C-LABELED HERBICIDES INCLUDING 2,4,5-T WERE APPLIED AS FOLIAR SPRAY AT 0.28 KG/HA IN A TERRESTRIAL MICROCOSM CHAMBER TO EXAMINE THEIR TRANSPORT AND METABOLISM IN COMPARISON TO DIELDRIN. TOTAL HERBICIDE RESIDUES IN SOIL AVERAGED 0.14 PPM FOR ALL COMPOUNDS BY 20 DAYS POSTTREATMENT. RYE GRASS SHOOTS CONTAINED 2.5 PPM 2,4,5-T. 2,4,5-T WAS ONE OF THE MOST RAPIDLY DECOMPOSED HERBICIDES.

TERRESTRIAL FATE: If released to soil, 2,4,5-T is likely to biodegrade and its mobility is expected to vary from highly mobile in sandy soil and moderately mobile in clay and silt loams to slightly mobile in muck (due to adsorption to humic acids and other organic matter). Removal by biodegradation apparently limits the extent of leaching, however, and groundwater contamination is likely only by rapid flow through large channels and deep soil cracks(1). 2,4,5-Trichlorophenol and 2,4,5-trichloroanisole the primary degradation product of 2,4,5-T in soil(2). The anisole is apparently formed by microbial methylation of the phenol. Chemical hydrolysis in moist soils should not be significant. The persistence of 2,4,5-T in soil is reported to vary from 14 to 300 days depending upon climatic conditions and population of soil microorganisms, but usually does not exceed one full growing season regardless of the application rate(2,3,4,5). Degradation under anaerobic conditions is much slower than under aerobic conditions, thus 2,4,5-T persists longer in flooded soils (half-life of less than or equal to 48 weeks) than in field moist soils.

AQUATIC FATE: Since 2,4,5-T has a pKa of 2.88 at 25 degC(1), it will be dissociated in water. If released to water, photochemical decomposition volatilization and biodegradation of 2,4,5-T should be the dominant removal mechanisms. 2,4,5-Trichlorophenol is the primary degradation product of 2,4,5-T in water. Data regarding the biodegradation of 2,4,5-T in soil suggest that biodegradation may contribute significantly to the degradation of 2,4,5-T in aquatic systems. The aquatic near surface half-life for direct photolysis has been calculated to be 15 days during summer at latitude 40 deg. Humic substances can photosensitize 2,4,5-T and humic induced photoreactions may dominate photodegradation processes when humic substance concentrations exceed 15 mg of organic C per liter. 2,4,5-T may also be degraded by photocatalytic processes involving iron species and peroxides. The primary products of 2,4,5-T photodegradation are 2,4,5-trichlorophenol and 2-hydroxy-4,5-dichlorophenoxyacetic acid. Adsorption of 2,4,5-T to humic acids in suspended solids and sediments may be significant. Oxidation, chemical hydrolysis, volatilization and bioaccumulation should not be significant. (SRC)

ATMOSPHERIC FATE: If released to the atmosphere, 2,4,5-T may exist in vapor form, as fine droplets and adsorbed on air-borne particulates as a result of vapor phase adsorption, or as a result of wind erosion of treated soils(1,SRC). 2,4,5-T has the potential to undergo (a) direct photolysis due to uv absorption at >290 nm, (b) reaction with photochemically generated hydroxyl radicals (estimated vapor phase half-life= 1.12 days) or (c) be physically removed by settling or washing out in rainfall(SRC).

For more Environmental Fate (Complete) data for 2,4,5-T (6 total), please visit the HSDB record page.

The substance can be absorbed into the body by inhalation of its aerosol and by ingestion.

inhalation, ingestion, skin and/or eye contact

CDDs cause their toxic effects by binding to the aryl hydrocarbon receptor and subsequently altering the trascription of certain genes. The affinity for the Ah receptor depends on the structure of the specific CDD. The change in gene expression may result from the direct interaction of the Ah receptor and its heterodimer-forming partner, the aryl hydrocarbon receptor nuclear translocator, with gene regulatory elements or the initiation of a phosphorylation/dephosphorylation cascade that subsequently activates other transcription factors. The affected genes include several oncogenes, growth factors, receptors, hormones, and drug-metabolizing enzymes. The change in transcription/translation of these genes is believed to be the cause of most of the toxic effects of CDDs. This includes 2,3,7,8-tetrachlorodibenzo-p-dioxin's carcinogenicity is thought to be the result of its ability to alter the capacity of both exogenous and endogenous substances to damage the DNA by inducing CYP1A1- and CYP1A2-dependent drug-metabolizing enzymes. (L177)

Plants collected from northeast Finland had the following /2,4,5-T/ residues: lingonberry: 0.07-15 ppm at 2-13 weeks after time of collection after herbicide spraying; wild mushroom: < 0.02-1.8 ppm at 2-13 weeks after time of collection after herbicide spraying; birch and aspen foliage: 0.1-30 ppm at 13-43 weeks after time of collection after herbicide spraying. /Initial concn applied not specified./

F027; As stated in 40 CFR 261.31, discarded unused formulations containing tri-, tetra-, or pentachlorophenol or discarded unused formulation containing compounds derived from these chlorophenols. (This listing does not include formulations containing hexachlorophene synthesized from prepurified 2,4,5-trichlorophenol as the sole component.)

Criteria of concern: Oncogenicity, mutagenicity, fetotoxicity. Action/Use affected: Cancelled, all products. Reference: PR Notice 70-22 September 28, 1970; 44 FR 15917 March 15, 1979; 44 FR 41536 July 17, 1979; 48 FR 48434 October 18, 1983. Ruling by an Administrative Law Judge, January 2, 1985.

Persons in charge of vessels or facilities are required to notify the National Response Center (NRC) immediately, when there is a release of this designated hazardous substance, in an amount equal to or greater than its reportable quantity of 1000 lb or 454 kg. The toll free number of the NRC is (800) 424-8802; In the Washington D.C. metropolitan area (202) 426-2675. The rule for determining when notification is required is stated in 40 CFR 302.4 (section IV. D.3.b).

2,4,5-T is designated as a hazardous substance under section 311(b)(2)(A) of the Federal Water Pollution Control Act and further regulated by the Clean Water Act Amendments of 1977 and 1978. These regulations apply to discharges of this substance. This designation includes any isomers and hydrates, as well as any solutions and mixtures containing this substance.

These hormonal agents /2,4-D & 2,4,5-T/ produce their effects by overstimulating plant growth.

To understand the mechanisms of toxicity of 2,4-dichlorophenoxyacetic acid (2,4-D) and 2,4,5-trichlorophenoxyacetic acid (2,4,5-T), ... their effect on the cytoskeletal organization, particularly microtubules (MT) and microfilaments (MF), DNA synthesis, and the synthesis and composition of cytoskeletal proteins in mouse 3T3 cells /was examined/. Exposure of cells to 2,4-D or 2,4,5-T resulted in a dose-dependent inhibition of DNA synthesis; 50% inhibition occurred at 2.21 mM and 0.90 mM for 2,4-D & 2,4,5-T, respectively. Furthermore, strong synergistic inhibition of DNA synthesis was produced by mixtures (each having a total concentration of 1.25 mM) of 2,4-D with 2,4,5-T. Similarly, 2,4,5-T is more potent than 2,4-D in causing cytoskeletal perturbation as revealed by fluorescence microscopy. Treatment of cells with 2,4-D (2.5 mM) or 2,4,5-T (1.25 mM) for 20 hr resulted in severe MT aggregation and the appearance of large bundles, which were organized in a rope-like structure in the former and a dramatic octopus-like pattern in the latter. Further, MT bundling is particularly severe in the cell center. Under these conditions, marked changes in MF organization also occurred as evidenced by clustering and crisscrossing of MF in the perinuclear region. A 1:1 mixture (final= 1.25 mM of 2,4-D and 2,4,5-T, a formulation equivalent to Agent Orange composition, also induced a dramatic perturbation to the organization of MT and MF, resulting in the formation of ring-like structures. MT bundling is still apparent, especially around the outer edge of the "rings." MF are localized predominantly along the cell periphery, where they appear to be aggregated tightly forming patches. Surprisingly, the synthesis and composition of cytoskeletal proteins, which are resistant to detergent extraction but released by CaCl2, are essentially unaffected by 2,4-D or 2,4,5-T. These results suggest that the dramatic perturbation of the cytoskeletal morphology caused by these herbicides probably only results from a structural reorganization and redistribution of MT and MF.

They exert their herbicidal action by acting as a growth hormone in plants. They have no hormonal action in animals, but their mechanism of toxic action is poorly understood. /Chlorophenoxy compounds/

/IN MALE SPRAGUE-DAWLEY RATS/ ALTHOUGH THE PLASMA HALF-LIFE OF ACUTE DOSES LESS THAN 50 MG/KG IS APPROX 4.2 HR, CHRONIC ADMIN OF SINGLE DAILY DOSES OF 20 MG/KG 2,4,5-T RESULTS IN APPARENT ACCUMULATION.

Five human male volunteers orally ingested a single dose of 5 mg/kg of 2,4,5-T. The clearance of 2,4,5-T from the plasma and its urinary excretion from the body occurred with half-lives of 23.10 and 23.06 hours, respectively.

(14)C-2,4,5-T was admin by stomach tube to pregnant & nonpregnant rats. ... The biological half-life in the various organs was essentially the same but differed between adult & newborn rats: 3.4 hr versus 97 hr, respectively. The plasma & elimination half-lives for Sprague-Dawley rats was 4.7 & 13.6, respectively, when a 5 mg/kg dose was admin.

When adult beagle dogs were admin 5 mg/kg doses, the half-life for plasma clearance & elimination was 77.0 & 86.6 hr, respectively.

THESE HERBICIDES /CHLOROPHENOXY CMPD/ DO NOT ACCUM IN ANIMALS. THEY ARE NOT EXTENSIVELY METAB BUT ARE ACTIVELY EXCRETED INTO THE URINE ... THEIR PLASMA HALF-LIFE IN MAN IS ABOUT 1 DAY. /CHLOROPHENOXY HERBICIDES/

WHEN WINESAP & STAYMEN /APPLE/ CULTIVATORS WERE EXPOSED TO 2,4,5-T, SOME DECARBOXYLATION OCCURRED.

BEAN PLANTS (PHASEOLUS), SUN FLOWERS (HELIANTHUS ANNUS) AND BARLEY (HORDEUM) CONVERTED 2,4,5-T TO ITS PHENOL.

FROM COMPARATIVE STUDIES WITH SENSITIVE AND INSENSITIVE PLANTS, 2 PATHS WERE PROPOSED, INVOLVING INITIAL GLUCOSE ESTER FORMATION AND OXIDATIVE RING CLEAVAGE TO YIELD MONOCHLOROACETATE. THE LATTER WAS DETECTED IN TREATED PLANTS PRIOR TO THE ONSET OF TREATMENT SYMPTOMS.

SEVEN DAYS AFTER ORAL ADMIN OF 50 MG/KG BODY WT 2,4,5-T (99.6% PURE) TO RATS, 56-69% OF DOSE WAS RECOVERED IN URINE: 70-85% OF RECOVERED DOSE WAS UNCHANGED 2,4,5-T, & APPROX 15-30% WAS FOUND AS GLYCINE & TAURINE CONJUGATES & AS 2,4,5-TRICHLOROPHENOL; TWO CONJUGATES WERE EXCRETED IN NEARLY EQUAL AMT. SIMILAR RESULTS WERE OBTAINED IN MICE, EXCEPT THAT THE QUANTITY OF TAURINE CONJUGATE WAS GREATER.

For more Metabolism/Metabolites (Complete) data for 2,4,5-T (9 total), please visit the HSDB record page.

CDDs are absorbed through oral, inhalation, and dermal routes of exposure. CDDs are carried in the plasma by serum lipids and lipoproteins, distributing mainly to the liver and adipose tissue. CDDs are very slowly metabolized by the microsomal monooxygenase system to polar metabolites that can undergo conjugation with glucuronic acid and glutathione. They may increase the rate of their own metabolism by inducing CDDs induce both phase I and phase II enzymes. The major routes of excretion of CDDs are the bile and the feces, though smaller amounts are excreted in the urine and via lactation. (L177)

2,4,5-T given orally to ... volunteers in doses of 100-150 mg was readily absorbed and gradually eliminated from blood plasma, showing first-order elimination rate; more than 80% of dose was excreted in urine in intact form within 72 hr. Daily urinary excretion ... in exposed workers was found to range from 0.5-3.6 mg/day in 11/21 samples.

... RESULTS ... OBTAINED WITH SINGLE IV INJECTIONS OF 5 OR 100 MG/KG BODY WT (14)C-2,4,5-T IN RATS, WHERE 2.3 & 7.6% OF RADIOACTIVITY WERE EXCRETED IN FECES, RESPECTIVELY, /SUGGESTED/ ... THAT @ HIGHER DOSE BILIARY EXCRETION OF 2,4,5-T &/OR ITS DEGRADATION PRODUCTS IS INVOLVED IN OVERALL ELIMINATION OF 2,4,5-T FROM THE BODY.

RADIOACTIVITY WAS FOUND IN ALL TISSUES EXAMINED AS WELL AS IN MILK & FETUSES AFTER SINGLE ORAL ADMIN OF 0.17-41 MG/KG BODY WT (14)C-2,4,5-T TO PREGNANT RATS.

SINGLE DOSE OF 100 MG/KG BODY WT 2,4,5-T TO PREGNANT MICE WAS ALMOST ENTIRELY ELIMINATED BY 72 HR; HOWEVER, AFTER 4 DAILY ADMIN OF SAME DOSE, 2,4,5-T ACCUMULATED IN MATERNAL TISSUES & FETUSES, & BY 48 HR 2,4,5-T WAS STILL DETECTABLE THROUGHOUT FETUSES.

For more Absorption, Distribution and Excretion (Complete) data for 2,4,5-T (19 total), please visit the HSDB record page.

Not produced in the U.S since 1983; [ACGIH]

All uses in the U.S. canceled in 1985; [EPA Pesticides, p. 95]

In March 1985 the EPA terminated all registrations for the use of this herbicide on rice fields, orchards, sugarcane, rangeland and other noncrop sites. This follows the 1970 of the Department of Agriculture halting the use of the pesticide on all food crops except rice ... .

For 2,4,5-T (USEPA/OPP Pesticide Code: 082001) 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./

2,4,5-T: U.S. Banned. /From table/

HERBICIDE FOR INDUSTRIAL SITES, LUMBER YARDS & VACANT LOTS, RANGELAND & RICE, LAWNS & TURF (INCL ITS ESTERS & SALTS), AQUATIC USE (INCL ITS ESTERS & SALTS), HOME USE (FORMER USE FOR GRANULES), RECREATION AREAS (FORMER USE FOR GRANULES), FOOD CROPS FOR HUMANS (FORMER USE).

Contaminants of commercial preparations of 2,4,5-T have been 2,3,7,8-tetrachlorodibenzo-p-dioxin ... & 2,3,6,7-tetrachlorodibenzo-p-dioxin ... .

2,4,5-T produced prior to 1965 contained 30 mg/kg or more TCDD /2,3,7,8-tetrachlorodibenzo-p-dioxin/. 2,4,5-T with dioxin content of less than 0.05 mg/kg is ... available in commercial quantities.

Concentration range of 2,3,7,8-tetrachlorodibenzo-p-dioxin in 6 samples of 2,4,5-T ranged from < 0.05-0.5 mg/kg. /From table/

... A typical batch from one producer was found to have the following composition: > 95% pure chemical, 2-9% dichloromethoxy phenoxy acetic acids, 0.6% related trichlorophenoxyacetic acids, 0.5% dichlorophenoxyacetic acids, 0.4% bis(2,4,5-trichlorophenoxy) acetic acid and less than 0.5 mg/kg 2,3,7,8-tetra-chlorodibenzo-para-dioxin ... .

For more Impurities (Complete) data for 2,4,5-T (6 total), please visit the HSDB record page.

(1977) 1.30X10+8 G (PRINCPL CUSTMS DISTS)

(1982) 1.39X10+8 G (PRINCPL CUSTMS DISTS)

(1983) 4.91X10+5 lb

(1977) NOT PRODUCED COMMERCIALLY IN USA

(1982) NOT PRODUCED COMMERCIALLY IN USA

TECHNICAL, 96-99%; 55-65% SOLUTIONS IN KEROSENE OR DIESEL OIL, WHICH ARE COMBUSTIBLE. /Former/

Emulsifiable concentrate; soluble concentrate. /Former/

Sylvoxone 850 (SOPRA), EC (650 g ae /acid equivalent/ 2,4,5-T-(iso-octyl)/l); EC (500 g ae/l) as ester; EC (480 g ae 2,4,5-T-(2-butoxyethyl)/l); SL /sol concentrate/ (480 g ae/l as amine salts). Mixtures include: Ban-Dock (Shell), SL (2,4,5-T + dicamba + mecoprop (as amine salts)); Nettle-Ban (Shell), SL (2,4,5-T + 2,4-D + dicamba (as amine salts)); Spontox (May & Baker), EC (2,4,5-t-)isoocyl) + 2,4,-D-(isoocyl)). /Former/

Farmco T-800 contains 800 g/l EC as mixed butyl ester; Farmco TA-200, 200 g/l ai as the dimethylamine salt; Farmco TLV-400 special, 400 g/l ai. EC as the iso-octyl; Farmco Tree-Kill is a technical mix of butyl esters; Farmco DT-400, 200 g/l ai. 2,4-D as the ethyl ester and 200 g/l ai. 2,4,5-T as the mixed butyl ester; Gold Coin, 2,4,5-T + ester, an oil soluble liquid, 800 g (ai)/l. /Former/

For more Formulations/Preparations (Complete) data for 2,4,5-T (10 total), please visit the HSDB record page.

Acetic acid, 2-(2,4,5-trichlorophenoxy)-: ACTIVE

The WHO Recommended Classification of Pesticides by Hazard identifies 2,4,5-T (technical grade) as an active ingredient believed to be obsolete or discontinued for use as a pesticide. The international trade of ... 2,4,5-T is regulated by the Rotterdam convention on Prior Informed Consent (see http://www.pic.int/), which entered force on 24 February 2004. According to the PIC Convention, export of /2,4,5-T/ can only take place with the prior informed consent of the importing Party. ...(further information can be found at: http://www.pic.int/)

Over the last 20 yr, 13 US companies at one time produced 2,4,5-T. As a result of the gradual cancellation of its various pesticide registrations since 1970, 2,4,5-T is no longer produced in the USA.

Registration note: Discontinued in the USA.

Mixing with solutions of heavy-metal salts, eg copper sulfate, can lead to flocculation.

For more General Manufacturing Information (Complete) data for 2,4,5-T (10 total), please visit the HSDB record page.