Trichlorophenoxyacetic acid

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

H315: Causes skin irritation [Warning Skin corrosion/irritation]

H319: Causes serious eye irritation [Warning Serious eye damage/eye irritation]

H335: May cause respiratory irritation [Warning Specific target organ toxicity, single exposure; Respiratory tract irritation]

H400: Very toxic to aquatic life [Warning Hazardous to the aquatic environment, acute hazard]

H410: Very toxic to aquatic life with long lasting effects [Warning Hazardous to the aquatic environment, long-term hazard]

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)

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

H315 (100%): Causes skin irritation [Warning Skin corrosion/irritation]

H319 (100%): Causes serious eye irritation [Warning Serious eye damage/eye irritation]

H335 (100%): May cause respiratory irritation [Warning Specific target organ toxicity, single exposure; Respiratory tract irritation]

H400 (97.7%): Very toxic to aquatic life [Warning Hazardous to the aquatic environment, acute hazard]

H410 (100%): Very toxic to aquatic life with long lasting effects [Warning Hazardous to the aquatic environment, long-term hazard]

Aggregated GHS information provided per 43 reports by companies from 4 notifications to the ECHA C&L Inventory. Each notification may be associated with multiple companies.

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.

H312: Harmful in contact with skin [Warning Acute toxicity, dermal]

H360: May damage fertility or the unborn child [Danger Reproductive toxicity]

H372: Causes damage to organs through prolonged or repeated exposure [Danger Specific target organ toxicity, repeated exposure]

H373: May causes damage to organs through prolonged or repeated exposure [Warning Specific target organ toxicity, repeated exposure]

P203, P260, P261, P264, P264+P265, P270, P271, P280, P301+P317, P302+P352, P304+P340, P305+P351+P338, P317, P318, P319, P321, P330, P332+P317, P337+P317, P362+P364, P403+P233, P405, and P501 (click each P-code to see the statement)

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.

SKIN: IMMEDIATELY flood affected skin with water while removing and isolating all contaminated clothing. Gently wash all affected skin areas thoroughly with soap and water. If symptoms such as redness or irritation develop, IMMEDIATELY call a physician and be prepared to transport the victim to a hospital for treatment.

INHALATION: IMMEDIATELY leave the contaminated area; take deep breaths of fresh air. IMMEDIATELY call a physician and be prepared to transport the victim to a hospital even if no symptoms (such as wheezing, coughing, shortness of breath, or burning in the mouth, throat, or chest) develop. Provide proper respiratory protection to rescuers entering an unknown atmosphere. Whenever possible, Self-Contained Breathing Apparatus (SCBA) should be used; if not available, use a level of protection greater than or equal to that advised under Protective Clothing.

INGESTION: DO NOT INDUCE VOMITING. If the victim is conscious and not convulsing, give 1 or 2 glasses of water to dilute the chemical and IMMEDIATELY call a hospital or poison control center. Be prepared to transport the victim to a hospital if advised by a physician. If the victim is convulsing or unconscious, do not give anything by mouth, ensure that the victim's airway is open and lay the victim on his/her side with the head lower than the body. DO NOT INDUCE VOMITING. IMMEDIATELY transport the victim to a hospital.

OTHER: Since this chemical is a known or suspected carcinogen you should contact a physician for advice regarding the possible long term health effects and potential recommendation for medical monitoring. Recommendations from the physician will depend upon the specific compound, its chemical, physical and toxicity properties, the exposure level, length of exposure, and the route of exposure. (NTP, 1992)

(General first aid procedures)

Eye: Irrigate immediately - If this chemical contacts the eyes, immediately wash (irrigate) the eyes with large amounts of water, occasionally lifting the lower and upper lids. Get medical attention immediately.

Skin: Soap wash - If this chemical contacts the skin, wash the contaminated skin with soap and water.

Breathing: Respiratory support

Swallow: Medical attention immediately - If this chemical has been swallowed, get medical attention immediately.

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

Use water spray, powder.

/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.

Excerpt from ERG Guide 154 [Substances - Toxic and/or Corrosive (Non-Combustible)]:

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 the immediate precautionary measure distance, in the downwind direction, as necessary.

FIRE: If tank, rail tank car or highway tank 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, 2024)

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.

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.

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.

Excerpt from ERG Guide 154 [Substances - Toxic and/or Corrosive (Non-Combustible)]:

ELIMINATE all ignition sources (no smoking, flares, sparks or flames) from 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, 2024)

Provision to contain effluent from fire extinguishing. Separated from food and feedstuffs. Store in an area without drain or sewer access.

DO NOT STORE NEAR OTHER AGROCHEMICALS OR SEEDS. DO NOT STORE IN FREEZING TEMPERATURES.

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)]

4.0 [mg/m3]

42 [mg/m3]

250 [mg/m3]

10 mg/m³

TWA 10 mg/m3

10.0 [mg/m3]

250 mg/m3 (NIOSH, 2024)

250.0 [mg/m3]

Excerpts from Documentation for IDLHs: Basis for original (SCP) IDLH: According to ACGIH [1971], the toxicity of this compound appears to be similar to the somewhat better known 2,4­D. According to Rowe and Hymas [1954], the oral LD50 values fall in a range of 300 to 1,000 mg/kg for rats, mice, guinea pigs, and rabbits. Chronic exposure is not necessarily more hazardous. Drill and Hiratzka [1953] found that there were no deaths among dogs treated with 2, 5, or 10 mg/kg/day of 2,4,5­T (5 days/week for 13 weeks); some deaths occurred at 20 mg/kg/day. There are no reports of illness from occupational exposure. It appears that the TLV of 10 mg/m3 is justified on the basis of extrapolation from animal feeding studies and extensive use experience. Based on the toxicological data cited above, 2,4,5­T is a relatively nontoxic compound. Because data on acute inhalation toxicology are not available for this substance and to be consistent with the IDLHs selected for similar, relatively nontoxic compounds, 5,000 mg/m3 (i.e., 500 times the OSHA PEL of 10 mg/m3) has been chosen as the concentration above which only the most protective respirators are permitted. . . . Basis for revised IDLH: No inhalation toxicity data are available on which to base an IDLH for 2,4,5­T. Therefore, the revised IDLH for 2,4,5­T is 250 mg/m3 based on acute oral toxicity data in animals [AAPCO 1966; Bailey and White 1965; Grant 1979; Senczuk and Pogorzelska 1980]. This may be a conservative value due to the lack of relevant acute inhalation toxicity data for workers.

250 mg/cu m

250 mg/m3

See: 93765

8 hr Time Weighted Avg (TWA): 10 mg/cu m.

Excursion Limit Recommendation: Excursions in worker exposure levels may exceed 3 times the TLV-TWA for no more than a total of 30 minutes during a work day, and under no circumstances should they exceed 5 times the TLV-TWA, provided that the TLV-TWA is not exceeded.

A4; Not classifiable as a human carcinogen.

10 mg/m³ [1992]

(inhalable fraction): 2 mg/m

Occupational exposure limits: Australia (1978) Time Weighted Avg (TWA) 10 mg/cu m; Belgium (1978) TWA 10 mg/cu m; Germany, Federal Republic of (1985) TWA 10 mg/cu m; The Netherlands (1978) TWA 10 mg/cu m; Norway (1981) TWA 5 mg/cu m; Switzerland (1978) TWA 10 mg/cu m; UK (1985) TWA 10 mg/cu m, Short Term Exposure (STEL) 20 mg/cu m; Yugoslavia (1971) Ceiling limit 10 mg/cu m

A harmful concentration of airborne particles can be reached quickly on spraying or when dispersed, especially if powdered.

The substance is irritating to the eyes and respiratory tract.

Animal tests show that this substance possibly causes toxicity to human reproduction or development.

Excerpt from NIOSH Pocket Guide for 2,4,5-T:

Skin: No recommendation is made specifying the need for personal protective equipment for the body.

Eyes: No recommendation is made specifying the need for eye protection.

Wash skin: No recommendation is made specifying the need for washing the substance from the skin (either immediately or at the end of the work shift).

Remove: No recommendation is made specifying the need for removing clothing that becomes wet or contaminated.

Change: No recommendation is made specifying the need for the worker to change clothing after the workshift. (NIOSH, 2024)

Wear appropriate chemical protective gloves, boots and goggles.

Recommendations for respirator selection. Max concn for use: 50 mg/cu m. Respirator Class(es): Any dust and mist respirator.

Recommendations for respirator selection. Max concn for use: 100 mg/cu m. Respirator Class(es): Any dust and mist respirator except single-use and quarter-mask respirators. Any supplied-air respirator.

Recommendations for respirator selection. Max concn for use: 250 mg/cu m. Respirator Class(es): Any supplied-air respirator operated in a continuous flow mode. Any air-purifying, full-facepiece respirator with a high-efficiency particulate filter. Any powered, air-purifying respirator with a dust and mist filter. Any self-contained breathing apparatus with a full facepiece. Any supplied-air respirator with a full facepiece.

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

NIOSH/OSHA

Up to 50 mg/m3 :

(APF = 5) Any quarter-mask respirator.

Click here for information on selection of N, R, or P filters.

Up to 100 mg/m3 :

(APF = 10) Any particulate respirator equipped with an N95, R95, or P95 filter (including N95, R95, and P95 filtering facepieces) except quarter-mask respirators. The following filters may also be used: N99, R99, P99, N100, R100, P100.

2,4,5-trichlorophenoxyacetic acid is a light tan solid (melting point 153 °C). Insoluble in water. Contact may irritate the skin.

Colorless to tan, odorless, crystalline solid. [herbicide]; [NIOSH]

WHITE CRYSTALLINE POWDER.

Colorless to tan, odorless, crystalline solid.

Colorless to tan, odorless, crystalline solid. [herbicide]

WHITE SOLID

LIGHT TAN SOLID

Colorless to tan crystalline solid.

Odorless

Odorless.

Decomposes (NTP, 1992)

Decomposes

No boiling point at normal pressure; decomposes on heating

decomposes

316 °F (NTP, 1992)

153-158 °C

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.

Solubility in water, g/100ml at 25 °C: 0.03

(77 °F): 0.03%

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

1.80 @ 20°C

0 mmHg at 68 °F approximately (NTP, 1992)

Less than 0.01 mPa @ 20 °C

Vapor pressure at 25 °C: negligible

1x10-7 mmHg

1 x 10-7 mmHg

log Kow= 4

STABLE @ ITS MELTING-POINT

SHELF LIFE EXCELLENT DEPENDING UPON MFR & FORMULATION; 2-YR MINIMUM

Conditions leading to instability: Temperatures above 158 °C may cause sealed metal containers to burst.

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

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

Non-corrosive, but some oil based formulations may be deleterious to painted surfaces.

Insoluble in water.

Acids, Carboxylic

Halogenated Organic Compounds

Aryl Halides

2,4,5-TRICHLOROPHENOXYACETIC ACID is a weak acid. Reacts with organic and inorganic bases to form water-soluble salts and with alcohols to form esters. Incompatible with strong oxidizing agents and strong bases. Can corrode metals, especially if moist. May harm painted surfaces (NTP, 1992).

None reported

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)

2,4,5-Trichlorophenoxyacetic acid (2,4,5-T)

1 x 10 ^-2 mg/kg-day

Pesticide

Smith, C.D. and Nowell, L.H., 2024. Health-Based Screening Levels for evaluating water-quality data (3rd ed.). DOI:10.5066/F71C1TWP

Classification of carcinogenicity: 1) evidence in humans: limited; Overall summary evaluation of carcinogenic risk to humans is Group 2B: The agent is possibly carcinogenic to humans. /Chlorophenoxy herbicides; From table/

A4; Not classifiable as a human carcinogen.

2B, possibly carcinogenic to humans. (L135)

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)

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

inhalation, ingestion, skin and/or eye contact

Cough. Sore throat.

Redness. Pain.

Diarrhoea. Drowsiness. Headache. Nausea. Vomiting.

In Animals: ataxia; skin irritation, acne-like rash; liver damage

In addition to chloracne, CDD exposure causes skin rashes, discoloration, and excessive body hair. (L177)

Skin, liver, gastrointestinal tract

Occupational hepatotoxin - Secondary hepatotoxins: the potential for toxic effect in the occupational setting is based on cases of poisoning by human ingestion or animal experimentation.

Reproductive Toxin - A chemical that is toxic to the reproductive system, including defects in the progeny and injury to male or female reproductive function. Reproductive toxicity includes developmental effects. See Guidelines for Reproductive Toxicity Risk Assessment.

ACGIH Carcinogen - Not Classifiable.

No-adverse-effect doses were: for 2,4,5-T, 10 mg/kg/day in dogs & mice & up to 30 mg/kg/day in rats; and for ... /2,3,7,8-tetrachlorodibenzo-p-dioxin a contaminant of 2,4,5-T/ 0.01 ug/kg/day in rats. Based on these data ... /acceptable daily intake was/ calculated at 0.1 mg/kg/day for 2,4,5-T ...

Acceptable daily intake for man is 0.03 mg/kg.

IRIS Current

HEAST Current

LD50 Mouse oral 389 mg/kg

LD50 Rat oral 500 mg/kg

LD50 Guinea pig oral 381 mg/kg

LD50 Dog oral > 100 mg/kg

LD50 Rat percutaneous > 5000 mg/kg

Treatment may include washing any areas of contact, GI decontamination if swallowed, administering an IV and forced alkaline diuresis. (L346)

... 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.

Consider the points /skin, liver, GI tract/ of attack in preplacement & periodic examinations.

Blood plasma & urine concn of 2,4,5-T appear to be directly related to the chemical absorbed by an individual. Limits have not been proposed for 2,4,5-T in specimens from exposed workers, but routine measurement of plasma or urine would be a useful tool in an industrial monitoring program.

2,4,5-T in pure form is considered to be of relatively low toxicity. In overdosage, the cmpd causes muscular weakness & stiffness, nausea, vomiting & diarrhea. ... 2,4,5-T itself is not believed to be carcinogenic or teratogenic in ... man; these effects, produced by technical grades of the chemical, are believed due to the dioxin that is present as an impurity.

CHROMOSOMAL ANALYSIS OF 52 WORKERS EXPOSED FOR VARIOUS PERIODS UP TO 960 DAYS TO 2,4,5-T (CONTAINING TCDD, /2,3,7,8-TETRACHLORODIBENZO-P-DIOXIN/ @ LESS THAN 1 PPM) @ 1.6-8.1 MG/DAY FAILED TO SHOW ANY ABNORMALITIES.

... AN INCREASE IN CHROMATID ABERRATIONS IN HUMAN WHITE CELLS CULTURED WITH 2,4,5-T AT CONCENTRATIONS OF 1X10-8 AND 1X10-5 MOLAR /HAS BEEN REPORTED/.

THE CAUSATIVE AGENT OF OCCUPATIONAL ACNE FROM EXPOSURE TO 2,4,5-T IS 2,3,7,8-TETRACHLORODIBENZODIOXIN (TCDD) WHICH IS A CONTAMINANT.

For more Human Toxicity Excerpts (Complete) data for 2,4,5-T (34 total), please visit the HSDB record page.

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.

6.30e+02

8.20e+03

1.60e+02

5.00e+00

6.80e-02

1.00e-02

Volatile

1.90e+03

2.50e+04

4.90e+02

The substance is very toxic to aquatic organisms. This substance does enter the environment under normal use. Great care, however, should be taken to avoid any additional release, for example through inappropriate disposal.

Release of 2,4,5-T to the environment occurred during its past use as a herbicide and it can form in the environment as a hydrolysis product of its herbicide esters. Other sources of release may include losses during formulation, packaging or disposal of 2,4,5-T, its esters and the acaricide, tetradifon. Since 2,4,5-T has a pKa of 2.88 it will be found in the dissociated form in all environmental media. If released in soil, 2,4,5-T can biodegrade and its mobility is expected to vary from highly mobile in sandy soil 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. 2,4,5-trichlorophenol and 2,4,5-trichloroanisole are the primary microbial degradation products of 2,4,5-T. Chemical hydrolysis in moist soils and volatilization from dry and moist surfaces should not be significant. The persistence of 2,4,5-T in soil is reported to vary between 14 to 300 days, but usually does not exceed one full growing season regardless of the application rate. Degradation under anaerobic conditions in flooded soils is much slower (half-life less than or equal to 48 weeks) than in field moist soils. If released to water, photochemical decomposition, volatilization and biodegradation of 2,4,5-T appear to be the dominant removal mechanisms. The primary degradation product of 2,4,5-T in water is 2,4,5-trichlorophenol. 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/l of organic C/l. Primary photodegradation products 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. If released to the atmosphere, 2,4,5-T should exist as fine droplets and adsorbed on airborne particulates. 2,4,5-T has the potential to undergo (a) direct photolysis due to uv absorption at >290 nm, (b) a reaction with photochemically generated hydroxyl radicals (estimated vapor phase half-life= 1.12 days) or (c) be physically removed by settling out or washout in rainfall. The most probable route of exposure to 2,4,5-T would be inhalation and dermal exposure of workers involved in the manufacture, handling or application of 2,4,5-T, related ester compounds or certain tetradifon formulations which contain 2,4,5-T. The general public could potentially be exposed by inhalation of particulate matter or ingestion of fruit, milk or drinking water contaminated with 2,4,5-T. (SRC)

Release of 2,4,5-T occurred during its past use as an herbicide on woody vegetation and as a weed control in rice, sugarcane and turf(1,6). 2,4,5-T can form in the environment as a hydrolysis product of 2,4,5-T esters(2). Losses during aerial and ground spraying account for nearly all 2,4,5-T released to the atmosphere(3). Between 0.05 to 2% of the 2,4,5-T and derivatives applied to soil is estimated to be lost in surface runoff(4). Other sources of release to the environment include loss during formulation, packaging and disposal of 2,4,5-T and its esters(3,SRC). Since 2,4,5-T has been found in the acaricide tetradifon (up to 4% by weight), release of 2,4,5-T to the environment may occur during manufacture, use or disposal of this pesticide although tetradefon is not used commercially anymore(5,SRC).

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.

Aerobic degradation of 10 ug 2,4,5-T of soil was 5-35% in unsterilized tropical clay and silty clay soils and <1% in sterilized soils after 4 months incubation(1). In Vietnamese soils, 64-69% aerobic degradation of 1 ppm 2,4,5-T occurred in 49 days, 74-96% aerobic degradation of 15 ppm 2,4,5-T occurred in 168 days and no degradation was observed in sterilized soils(2). The primary degradation product of 2,4,5-T in aqueous and soil systems is 2,4,5-trichlorophenol(3). Aerobic metabolism of 2,4,5-T leads to formation of 2,4,5-trichlorophenol and 3,5-dichlorocatechol which may further degrade to 4-chlorocatechol or cis,cis-2,4-dichloromuconic acid, 2-chloro-4-carboxy-methylene-but-2-enolide, chlorosuccinic acid and succinic acid(2). Degradation under anaerobic conditions has led to the formation of di- and mono-chlorophenols and 2,5-dichlorophenoxyacetic acid(4,5). Anaerobic degradation occurs much more slowly than aerobic degradation(6).

In long-term degradation studies of massive quantities of 2,4-D and 2,4,5-T in test grids, field plots and herbicide storage areas were carried out. The method of herbicide application had significant impact on the amount applied per unit area and hence on residue persistence: spills > or = soil incorporation > aerial application. 2,4,5-T was more persistent in the soil than 2,4-D. The formulation of the herbicide also had significant impact on its persistence: isooctyl ester > butyl ester > acid. The addition of coconut charcoal increases persistence of the phenoxy herbicide residues, especially residues of 2,4,5-T. The appearance of dichlorophenol and trichlorophenol in soils treated with 2,4-D and 2,4,5-T suggests that they are degradation products of the herbicides. A massive concn of herbicides does not sterilize the soils. Apparently, microbial populations respond both quantitatively and qualitatively to the presence of high concentrations of herbicides and may play an important role in their degradation. The contaminant 2,3,7,8-tetrachlorodibenza-p-dioxin had a long persistence time in soils (years) and may be a major consideration in the use of soil (years) and may be a major consideration in the use of soil biodegradation as a disposal option for unwanted phenoxy herbicides or 2,3,7,8-tetrachlorodibenza-p-dioxin contaminated chemical wastes.

THE MAJOR PRODUCT OF PHOTODECOMPOSITION OF 2,4,5-T IS 2,4,5-TRICHLOROPHENOL. THE LATTER GAVE RISE TO 4,5-DICHLORORESORCINOL, 4-CHLORORESORCINOL & 2,5-DICHLOROPHENOL. 2 OTHER COMPOUNDS WERE IDENTIFIED AS 2-HYDROXY-4,5-DICHLOROPHENOXYACETIC ACID & 2,4,5-TRICHLOROANISOLE.

This compound should be resistant to hydrolysis and oxidation(SRC). Based on reaction quantum yields, the aquatic near surface half-life for direct photolysis of 2,4,5-T onion has been calculated to be 15 days during summer at latitude 40 deg(1). Dissolved humic substances have been found to photosensitize 2,4,5-T and it is estimated that humic induced photoreactions dominate photodegradation processes in natural waters where humic substance concentrations exceed 15 mg of organic C/l. In clear, acidic, natural waters, 2,4,5-T may also be degraded by photocatalytic processes involving iron species and peroxides(1). Major photodecomposition products of 2,4,5-T in aqueous systems at pH 10 are the 2,4,5-trichlorophenol anion and 2-hydroxy-4,5-dichlorophenoxyacetic acid. Minor photodecomposition products include 4,6-dichlororesorcinol, 4-chlororesorcinol, 2,5-dichlorophenol and a dark polymeric product(2). Adsorption of uv light wavelengths >290 nm and the observed photolysis of 2,4,5-T in aqueous systems suggest that 2,4,5-T may undergo direct photolysis in the atmosphere(3,SRC). Vapor phase 2,4,5-T should react with photochemically generated hydroxyl radicals. The estimated hydroxyl reaction half-life is 1.12 days based on an ambient hydroxyl concn of 8.0X10+5 molecules/cu cm and an estimated reaction rate constant of 4.59X10-13 cu cm/molecule-sec at 25 °C(4).

In sunlight, the photolysis of 2,4,5-T (1 mg/l aqueous /salt/ solution) was very slow. However, the presence of low levels of acetone, or riboflavin in the solution resulted in a marked increase in the rate of 2,4,5-T disappearance, with 80% being degraded in 48 hr.

Removal of the side chain of 2,4,5-T gives 2,4,5-trichlorophenol; this is followed by replacement of chlorines on the ring by a hydroxyl group or a hydrogen. When the chlorine at the 2-position is replaced by a hydroxyl group in 2,4,5-T, the 1,4-dioxane ring is formed by dehydration between carboxyl and hydroxyl groups. /Conditions: light (uv light, in indoor & sunlight in outdoor conditions; medium: water/

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

The bioconcentration factor (BCF) of 2,4,5-T in static ecosystem tests has been measured to be 23-25 in fish(1,2). Under flowing water conditions its estimated BCF in fish is 43(1). Based on these BCF values, bioconcentration in aquatic organisms should not be significant.

Measured soil adsorption coefficient (Koc) values for 2,4,5-T in various soils are as follows: 86-sand, 186-whole soil, 204-fines, 205-coarse clay, 206-coarse silt and 280-medium silt(1). Measured soil TLC Rf values are as follows: 0.17-muck, 0.48-clay, 0.54-silt clay loam and 0.73-0.89-sandy loam(2). These Koc and Rf values indicate that 2,4,5-T mobility in soil should vary from highly mobile in sandy soil to moderately mobile in clay and silt loams to slightly mobile in muck (3,4). Humic acids found in almost all water and soil systems have been shown to strongly adsorb 2,4,5-T from solution(5), and the tendency of 2,4,5-T to adsorb to soil has been observed to increase with increasing organic content in soil(6). When 11.2 kg/ha 2,4,5-T was applied to a large field lysimeter, 96-99% of the undegraded herbicide remained 0-10 cm deep and 0.33-3.7% remained between 10 to 30 cm deep after 2-3 winters(7). Up to 8 weeks following application of 1 g/cu m 2,4,5-T, 86-98% of the undegraded 2,4,5-T applied to arable land remained within the top 30 cm of the soil layer and 84-100% remained within the top 10 cm of forest soil(8).

Based on an estimated vapor pressure of less than 7.5X10-8 mm Hg (at 25 °C) and a water solubility of 268 mg/l (at 25 °C)(1,2), the calculated Henry's Law Constant for 2,4,5-T is less than 9.4X10-11 atm cu cm/mol at 25 °C(SRC). This value for Henry's Law Constant indicates volatilization from water and wet soil surfaces should be insignificant(3). Considering the relatively low vapor pressure of 2,4,5-T, volatilization from dry soil surfaces should also be insignificant(SRC).

SURFACE WATER: During the 1976- 1980 national surface water monitoring program 2,4,5-T occurred in 0.4% of water samples and the maximum detectable concentration was 12.90 ug/l(1). In Allen County, Indiana from 1977 to 1978 - 8 samples, 100% pos - 1.0-7.7 ug/l 2,4,5-T detected, mean value 3.0 ug/l(2). In western Canada from 1971 to 1977 - 1426 samples, 8.2% pos. - <0.002 to 3.12 ug/l 2,4,5-T detected, mean value <0.002-0.090 ug/l(3). In Ontario, Canada from 1975 to 1977 - 949 samples, 2.2% pos. - 0.1-1.1 ug/l 2,4,5-T detected, mean value <0.1 ug/l(4). In Western U.S. from 1967 to 1971, levels of 2,4,5-T ranged from ND to 0.40 ug/l (5,6).

DRINKING WATER: 2,4,5-T has been qualitatively identified in drinking water(1).

Soil samples from areas sprayed in 1964-65 in connection with military defoliation operations in South Vietnam were collected in 1971 and analyzed for herbicide persistence. Where the highest amounts had been sprayed (1075 kg/ha), in order to calibrate aerial spray equipment, concentrations of up to 1.5 kg/ha were recovered after 6-7 yr. When 88.5 kg/ha 2,4,5-T had been applied between 1965-68, levels of between 0.022 and 0.27 kg/ha were recovered in 1971-72 in 2/3 of the samples.

SEDS: During 1976-1980 national surface water monitoring program, 2,4,5-T occurred in 0.2% of sediments sampled with a maximum detected concentration of 9.1 ppb(1). SOILS: Levels ranging from ND to >0.1 ppm 2,4,5-T were found within the top 6 inches of soil in 5 western Alabama counties(2).

2,4,5-T was identified in dust precipitated from the atmosphere at a level of 40 ng/g and qualitatively identified in rain from Cincinnati, OH(1).

2,4,5-T was detected in 1 sample of large fruit and 3 samples of fluid milk in 1971(1).

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./

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.

NA 2765; 2,4,5-Trichlorophenoxyacetic acid

UN 2765; Phenoxy pesticides, solid, toxic, not otherwise specified

49 411 85; 2,4,5-Trichlorophenoxyacetic acid

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.

Do not transport with food and feedstuffs.

Symbol: Xn, N; R: 22-36/37/38-50/53; S: (2)-24-60-61

UN Hazard Class: 6.1; UN Pack Group: III