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    WORLD HEALTH ORGANIZATION             FOOD AND AGRICULTURE
                                          ORGANIZATION
    ORGANISATION MONDIALE DE LA SANTE     ORGANISATION POUR L'ALIMENTATION
                                          ET L'AGRICULTURE

                                      
                                          VBC/DS/75.13       
                                          ORIGINAL:  ENGLISH 


   DATA SHEETS ON PESTICIDES No. 13

   1975


   2,4,5-T
                             ..........................




         It must be noted that the issue of a Data Sheet for a
    particular pesticide does not imply endorsement of the pesticide by
    WHO or FAO for any particular use, or exclude its use for other
    purposes not stated. While the information provided is believed to
    be accurate according to data available at the time when the sheet
    was compiled, neither WHO nor FAO are responsible for any errors or
    omissions, or any consequences therefrom.

    The issue of this document does    Ce document ne constitue pas une
    not constitute formal              publication. Il ne doit faire
    publication. It should not be      l'objet d'aucun compte rendu ou
    reviewed, abstracted or quoted     résumé ni d'aucune citation sans
    without the agreement of the       l'autorisation de l'Organisation
    Food and Agriculture               des Nations Unies pour
    Organization of the United         l'Alimentation et l'Agriculture
    Nations or of the World Health     ou de l'Organisation Mondiale de
    Organization.                      la Santé.


                                      2,4,5-T

    Part 1 - General information 
 
             CLASSIFICATION

             Primary use:  herbicide

             Secondary uses:  none

             Chemical group:  chlorinated phenoxy acid

             Data sheet No. 13

             Date issued:  March 1975

        
    1.1   COMMON NAME: 2,4,5-T

          Identity: 2,4,5-trichlorophenoxyacetic acid

    Figure 1

    Under good manufacturing conditions, a typical production lot of the 
    technical material assayed about 95% 2,4,5-trichlorophenoxyacetic acid, 
    about 5% homologous and isomeric acids and less than 0.1 ppm of 
    2,3,4,7,8-tetrachlorodibenzo-p-dioxin (TCDD).  This last impurity is
    a highly toxic material whose toxic effects are highly species
    dependent. Under poorly controlled manufacture it has been reported to 
    be present in one commercial sample of 2,4,5-T at a level of 
    approximately 27 ppm. Current production specifications limit TCDD 
    to 0.1 ppm. 

    Synonyms:  none                              Local synonyms:

    1.2   SYNOPSIS: A moderately toxic chlorinated phenoxy acid herbicide 
    which is rapidly excreted after ingestion. 

        
    1.3   SELECTED PROPERTIES

    1.3.1 Physical characteristics: The pure acid is a white crystalline
    solid with a melting point of 158°C. 

    1.3.2 Solubility: The pure acid is slightly soluble in water (278 ppm)
    at 25°C and soluble (58.4%) in alcohol. 
            
    1.3.3 Stability: The technical acid is stable under normal conditions.

    1.3.4 Vapour pressure: (volatility) No information.  The volatility of
    the pure acid can be expected to be low. 

     
    1.4   AGRICULTURAL, HORTICULTURAL AND FORESTRY

    1.4.1 Common formulations

    Various salts, amine salts and esters, the salts as aqueous 
    concentrates and esters as emulsifiable concentrates.

    Often formulated in mixtures with 2,4-D.  There are FAO specifications 
    for ester emulsifiable concentrates and amine salt aqueous solutions. 

    1.4.2 Susceptible pests

    Woody plants and non-woody broadleaf plants.  Little effect on 
    monocotyledonous species.  Less effective than 2,4-D on some broadleaf, 
    but more effective on woody plants. 

    1.4.3 Use pattern

    Selective control of weeds in cereal crops and lawns, nettles in 
    pasture and woody weeds in forestry, particularly with conifers. Mainly 
    used on non-edible crops.  Types of treatment include foliage 
    treatment, basal bark treatment, stump treatment, frill treatment and 
    tree injection. 

    1.4.4 Unintended effects

    Toxic to almost all broadleaf plants.  Highly susceptible crops include 
    cotton, tomatoes, ornamentals, grapes and fruit trees.  Danger of 
    contamination of irrigation ditches. 


        
    1.5   PUBLIC HEALTH PROGRAMMES

          No known use.

        
    1.6    HOUSEHOLD USE

          Used in home gardens for broadleaf weed control in grass.
          
          
                                     2, 4, 5-T

    Part 2 - Toxicology and risks      

              Common name:  2,4,5-T 

              Data sheet No. 13 

              Date issued:  March 1975 
       

    2.1   TOXICOLOGY - MAMMALS 

    2.1.1 Absorption route: Readily absorbed from the gastrointestinal 
    tract; also presumably absorbed if inhaled.  Skin absorption is slight. 

    2.1.2 Mode of action: No information. 

    2.1.3 Excretion products

    Single oral doses of (carboxy 14C) 2,4,5-T were administered to 
    groups of 3 male and 3 female adult Spague-Dowley rats and 2 male and 2 
    female adult beagle dogs. 

    The half-life values for the clearance of 14C activity from the 
    plasma of rats given doses of 5, 50, 100 or 200 mg/kg were 4.7,
    4.2, 19.4 and 25.2 hours respectively.  Urinary excretion of
    unchanged 2,4,5-T accounted for most of the 14C activity eliminated
    from the body of rats.  A small amount of unidentified metabolite was
    detected in the urine when rats were given 100 or 200 mg/kg but not 5
    or 50 mg/kg.  These results show that the distribution, metabolism and
    excretion of 2,4,5-T are markedly altered when large doses are
    administered.  In dogs given 5 mg/kg, the half-life values for 
    clearance from the plasma and elimination from the body were 77.0 and 
    86.6 hours respectively.  Appreciable excretion in the faeces was
    noted and three unidentified metabolites were detected in urine of 
    dogs, indicating a considerable difference in metabolism of 2,4,5-T
    by dogs and rats given the same dose. 

    2.1.4 Toxicity, single dose

    Oral: LD50, rat 500 mg/kg

    Dermal: No information

    Most susceptible species: dog LD50 100 mg/kg

    2.1.5 Toxicity, repeated doses

    Oral: dogs survived a 90-day feeding test at 10 mg/kg for five days a
    week; dogs died. 

    Inhalation:  No information

    Cumulation of compound: 2,4,5-T does not appear to accumulate in
    mammalian tissues as judged by its rapid excretion.

    Cumulation of effect: in the dog, the repeated daily dose necessary to 
    cause mortality is about one-fifth of the single dose, therefore, there 
    must be some accumulation of effect but the nature of this effect is 
    not known. 

    2.1.6 Dietary studies

    Short-term: rats were fed diets adjusted so that they received 0, 3, 
    10, 30 or 100 mg/kg of 2,4,5-T daily for 90 days.  Evidence of compound 
    related effects was minimal and limited to the animals given 30 and 100 
    mg/kg daily.  Changes included depression in body-weight gain, slight 
    decrease in food intake and elevated serum alkaline phosphatase levels. 
    There were no effects at 3 or 10 mg/kg. 

    Long-term:  No information

    2.1.7 Supplementary studies of toxicity

    Teratogenicity

    Mouse: A significant increase in cleft palate and cystic kidney was 
    observed in the foetuses from pregnant mice which were given 46.4 or 
    113 mg/kg of 2,4,5-T (containing about 30 ppm of TCDD) orally on 
    gestation days 6 to 14 or 9 to 17 inclusive.  A sample of 2.4,5-T 
    containing < O.1 ppm of TCDD was injected in dimethylsulfoxide solution 
    at a single dose level of 100 mg/kg on gestation days 6 to 15 
    inclusive.  There was significant increase in incidence of cleft palate 
    and "kidney involvement".  When a similar test was performed with 
    commercial 2,4,5-T containing about 0.5 ppm of TCDD there were no 
    adverse effects at 50 or 100 mg/kg but at 150 mg/kg there was increase 
    in the numbers of cleft palates and increased foetal mortality but no 
    "kidney involvement".  Pure TCDD at doses of 1 or 3 µg/kg caused 
    "kidney involvement" in all tests but resulted in significant increases 
    in cleft palate and foetal mortality in some tests, not in others. 

    Rat: 2,4,5-T containing about 30 ppm of TCDD produced a significant
    increase in foetal mortality and abnormal litters when administered 
    orally at 4.6 mg/kg on gestation days lo to 15 inclusive (the lowest 
    level tested).  Cystic kidney appeared to be the major manifestation of 
    abnormality. 

    Increased foetal mortality but no terata resulted when 150 mg/kg of 
    TCDD free 2,4,5-T was administered orally to rats on days 13 and 14 of 
    gestation.  In a separate study no teratogenic or embryotoxic effects 
    were observed when 2,4,5-T containing < 1 ppm of TCDD was administered 
    in levels up to 24 mg/kg on gestation days 6 to 15 inclusive.  The no 
    effect level with respect to teratogenic effects in the rat from TCDD 
    alone when administered on gestation days 6 to 15 inclusive was 0.03 
    )ag/kg. 

    Rabbit: When 2,4,5-T containing < 1 ppm of TCDD was administered to 
    rabbits at a maximum dose level of 40 mg/kg on gestation days 6 to 18 
    inclusive there was no evidence of embryotoxic or teratogenic effects. 

    Hamster: Commercial samples of 2,4,5-T were foeticidal and 
    teratogenic in the hamster when administered orally on gestation days 
    6 to 10 inclusive, and the incidence of these effects The abnormalities 
    consisted chiefly of absence of eyelids increased with the content of 
    TCDD. and delayed head ossification. 

    Carcinogenicity

    Mouse: There was no increase in tumour incidence in mice fed 60 ppm 
    (9.0 mg/kg/day) of 2,4,5-T for 18 months. 

    2.1.8 Modifications of toxicity

          No information.

        
    2.2   TOXICOLOGY - MAN

    2.2.1 Dangerous doses

    Single:  No information.  It has been stated that the oral dose 
    required to produce symptoms in man is probably 3-4 g.

    Repeated:  No information.

    2.2.2 Observations of occupationally exposed workers

    Extensive physical examinations revealed no differences between 130 
    employees engaged from 2 months to 3 years in the manufacture of 2,4,5-
    T and a control group of 4600 men.  When karyotyping was carried out on 
    52 exposed men, there was no indication that 2,4,5-T exposure had 
    affected the structural integrity or rearranged the genetic material of 
    the lymphocyte chromosomes.  Sporadic outbreaks of severe acne have 
    been encountered in workers in chemical plants where 2,4,5-
    trichlorophenol (a precursor in the manufacture of 2,4,5-T) is 
    manufactured or used.  It is stated that one of the agents responsible 
    is TCDD. 

    In another study there was a moderately high incidence of urinary 
    porphyria, chloracne and hirsutism in workers employed in factories 
    manufacturing chlorinated phenols.  A study of 73 male employees was 
    made in a 2,4,5-T factory.  Chloracne was found in 13 (18%) of the 
    workers. 

    2.2.3 Observations of exposure of the general population

    No substantiated information, although there have been allegations that 
    a rise in congenital abnormalities has been coincidental with use of 
    2,4,5-T.  No dose relation has been demonstrated nor is the TCDD 
    content of the batches known. 

    2.2.4 Observations of volunteers

    Five human male volunteers ingested a single dose of 5 mg/kg. 
    Concentrations of 2,4,5-T in plasma and its excretion were measured at 
    intervals after ingestion.  The clearance of 2,4,5-T from the plasma as 
    well as its excretion from the body occurred via apparent first order 
    rate processes with half-lives of 23.60 and 23.06 hours respectively. 
    Essentially all of the 2,4,5-T was absorbed into the body and excreted 
    unchanged in the urine.  In the body, 65% of the 2,4,5-T resided in the 
    plasma where 98.7% was bound reversibly to protein. 

    2.2.5 Reported mishaps

          No information.

            
    2.3   TOXICITY TO NON-MAMMALIAN SPECIES

    2.2.1 Fish

          Toxic to fish.

    2.3.2 Birds

          Low toxicity.

    2.3.3 Other species

          Toxicity to bees is low.

    Toxicity to all species is increased if the level of TCDD impurity (see 
    Section 1.1) exceeds a few ppm. 

                                      2,4,5-T

    Part 3 - For regulatory authorities           

             Common name:  2,4,5-T

             Data sheet No. 13

             Date issued:  March 1975


    RECOMMENDATIONS ON REGULATION OF COMPOUND

    3.1   RECOMMENDED RESTRICTIONS ON AVAILABILITY

    All formulations - (for definition of categories see introduction) 
    Liquids formulations over 25% category 4, neat solid formulations
    category 4. All other formulations, category 5. 

    3.2   TRANSPORTATION AND STORAGE 

    All formulations

    Should be transported or stored in clearly labelled impermeable 
    containers under lock and key and out of reach of children and away 
    from containers of food and drink. 


    3.3   HANDLING

    All formulations

    Protective clothing (see part 4) should be provided for those handling 
    the compound.  Adequate washing facilities should be available close at 
    hand.  Eating, drinking and smoking should be prohibited during 
    handling and before washing after handling. 

        
    3.4   DISPOSAL AND/OR DECONTAMINATION OF CONTAINER

    If not decontaminated, container must either be burned or crushed and 
    buried below topsoil.  Care must be taken to avoid subsequent 
    contamination of water sources.  Container may be decontaminated (for 
    method, see paragraph 4.3 or part 4). Decontaminated containers should 
    not be used for food and drink. 


    3.5   SELECTION, TRAINING AND MEDICAL SUPERVISION OF WORKERS

    All formulations

    Pre-employment medical examination of workers desirable.  Women in 
    their reproductive years and particularly pregnant women should be 
    excluded from contact. 


        
    3.6   ADDITIONAL REGULATIONS RECOMMENDED IF DISTRIBUTED BY AIRCRAFT

    Pilot and loaders should have special training in application methods.  
    Flagmen, if used, should wear overalls and be located well away from 
    the dropping zone. 


    3.7   LABELLING

    Minimum cautionary statement 

      "Keep well away from foodstuffs, animal feed and their containers." 


    3.8   RESIDUES IN FOOD

    Residue levels have not been recommended by the Joint FAO/WHO meeting 
    on Pesticide Residues. 


                                     2, 4, 5-T

    Part 4 - Prevention of poisoning in man and emergency aid

             Common name:  2.4,5-T
 
             Data sheet No. 13

             Date issued:  March 1975


    4.1   PRECAUTIONS IN USE

    4.1.1 General

    2,4,5-T is a chlorinated phenoxy acid herbicide of moderate toxicity.  
    It is rapidly absorbed by the gastrointestinal tract and is also 
    presumably absorbed if inhaled, but skin absorption is slight. After it 
    is ingested it is rapidly excreted as soluble salts in the urine. 

    4.1.2 Manufacture and formulation

          T.L.V.

          (ACGIH) 10 mg/m3;  (USSR). 

    Although volatility is low, vapour and dusts should be controlled 
    preferably by mechanical means.  Protective equipment for the skin and 
    respiratory protection is usually necessary. 

    4.1.3 Mixers and applicators

    When opening the container and when mixing, care should be taken to 
    avoid contact with the mouth and eyes.  If necessary, a facial visor 
    should be worn.  Mixing, if not mechanical, should always be carried 
    out with a paddle of appropriate length.  The applicator should avoid 
    working in spray mist and avoid contact with the mouth.  Splashes 
    should be washed immediately from the skin or eyes with large 
    quantities of water.  Before eating, drinking or smoking, hands and 
    other exposed skin should be washed. 

    4.1.4 Other associated workers (including flagmen in aerial operations)

    Persons exposed to 2,4,5-T and associated with its application should 
    observe the precautions described above in 4.1.3 under "mixers and 
    applicators". 

    4.1.5 Other populations likely to be affected

    With good agricultural practice subject to 4.2 below, other populations 
    should not be exposed to hazardous amounts of 2,4,5-T. 
        

    4.2   ENTRY OF PERSON INTO TREATED AREAS

          Pregnant women are advised not to enter sprayed areas.

       
    4.3   DECONTAMINATION OF SPILLAGE AND CONTAINERS

    Residues in containers should be emptied in a diluted form into a deep 
    pit taking care to avoid ground waters.  The empty container may be 
    decontaminated by rinsing two or three times with water and scrubbing 
    the sides.  An additional rinse should be  carried  out  with 5% sodium 
    hydroxide solution which should remain in the container overnight.  
    Impermeable gauntlets should be worn during this work and a soakage pit 
    should be provided for the rinsings.  Decontaminated containers should 
    not be used for food and drink.  They  should also never be used even 
    temporarily for transfer mixing or storage of other pesticides intended 
    for use on plants.  Spillage of 2,4,5-T should be removed by washing 
    with 5% sodium hydroxide solution and then rinsing with large 
    quantities of water. 
     

    4.4   EMERGENCY AID

    4.4.1 Early symptoms of poisoning

    Information on the symptoms of 2,4,5-T poisoning is very limited. There 
    will probably be weakness and perhaps lethargy with anorexia and 
    diarrhoea.  Muscle weakness may be present and may involve the muscles 
    of mastication and swallowing. 

    4.4.2 Treatment before person is seen by a physician if these symptoms 
          appear following exposure 

          If the pesticide has been ingested, vomiting should be induced.
           

                                      2,4,5-T

    Part 5 - For medical and laboratory personnel

              Common name:  2,4,5-T   
                                                                  
              Data sheet No. 13     
                                                                
              Date issued:  March 1975
                                        

    5.1   MEDICAL DIAGNOSIS AND TREATMENT OF CASES OF POISONING

    5.1.1 General information

    2,4,5-T is a phenoxy acetic acid herbicide of moderate toxicity.  It is 
    rapidly absorbed by the gastrointestinal tract and is also presumably 
    absorbed if inhaled but skin absorption is slight.  It is rapidly 
    excreted as soluble salts in the urine and does not persist in body 
    tissues. 

    5.1.2 Symptoms and signs

    Information on the signs and symptoms of poisoning by 2,4,5-T are very 
    limited.  There will probably be weakness and perhaps lethargy with 
    anorexia and diarrhoea.  Muscle weakness may be present and may involve 
    the muscles of mastication and swallowing.  More serious symptoms may 
    be ventricular fibrillation and/Or cardiac arrest and death.  Following 
    prolonged exposure to 2,4,5-T, and its precursors, chlorvaine, 
    hirsutism and urinary porphyri have been reported. 

    5.1.3 Laboratory

    The presence of 2,4,5-T or its salts in urine is indicative of 
    absorption, but sophisticated laboratory facilities are required. 

    5.1.4 Treatment

    If 2,4,5-T has been ingested, unless the patient is vomiting, gastric 
    lavage should be performed with 2-3 litres of tap water.  Other 
    treatment should be supportive. 

    5.1.5 Prognosis

          Not known.

    5.1.6 References of previously reported cases

    No information.  The description of symptoms is based on human 
    observations with related compounds (e.g. 2,4-D) and upon animal 
    studies performed with 2,4,5-T. 


    5.2   SURVEILLANCE TESTS

          There are no practical surveillance tests.

        
    5.3   LABORATORY METHODS

          References are given only.

    5.3.1 Detection and assay of compound

    A microcoulometric gas-chromatographic method for determining 2,4,5-T 
    and its propylene glycol butyl ester after conversion to the methyl 
    ester, at levels down to 0.05 ppm in animal tissue, blood and urine is 
    given by Clark (1969).  The method should be adaptable to other esters 
    and other substrates.  Gas chromatography has been used to determine 
    2.4,5-T in water (Hindin, 1964) and apples (Edgerton & Lisk, 1963).  
    Other gas chromatography methods are given by Zweig & Sherma (1972).  
    Clean-up procedures are described by the US Food and Drug 
    Administration (1971). 

    5.3.2 Other tests in cases of poisoning

          None.
          

                                     REFERENCES

    Clark, D. E. (1969) Determination of 2,4,5-trichlorophenoxyacetic acid
          and its propylene glycol butyl ether esters in animal  tissue, 
          blood and urine, Agric. Fd. Chem., 17, 1168 

    Edgerton, L. J. & Lisk, D. L. (1963) Determination of residues of
          2,4,5-trichlorophenoxyacetic acid in apples by radioisotope and 
          gas chromatographic methods, Proc. Amer. Soc. Hort. Sci., 83,
          120 

    Hindin, E., May, D.S. & Dunstan, G. H. (1964) Collection and analysis 
          of synthetic organic pesticides from surface and ground water, 
          Residue Reviews, 7, 130 

    US Food and Drug Administration (1971) Pesticide Analytical Manual,
          Vol. I, Sections 221, 222 

    Zweig, G. & Sherma, J. (1972) In: Zweig, G., ed., Analytical Methods 
          for Pesticides, Plant Growth Regulators and Food Additives, 
          Vol. VI, Academic Press, New York and London, pp. 633, 702