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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/75.9 (Rev.1)
                                          ORIGINAL: ENGLISH


    DATA SHEETS ON PESTICIDES No. 9 Rev.1


    CAPTAN

         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.


    CLASSIFICATION:

    Primary uses: Fungicide

    Secondary uses: None

    Chemical group: Sulfenimide

    Data sheet No. 9, Rev.1 (September 1978)


    1.    GENERAL INFORMATION

    1.1   COMMON NAME: captan (ISO)

    1.1.1 Identity: 3a,4,7,7a-tetrahydro-2- (1,1,2,2-tetrachloro-
          methyl)thio-1H-isoindole-1,3(2H)-dione. 

    Figure 1

    1.1.2 Synonyms: None 

          Local synonyms:

    1.2   SYNOPSIS - A sulfenimide fungicide of very low mammalian toxicity 
          which is rapidly hydrolysed in body tissues. It is fairly 
          persistent on crop surfaces. 


    1.3   SELECTED PROPERTIES

    1.3.1 Physical characteristics - When pure a white crystalline solid 
          m.p. 178°C.  The technical material is a yellow amorphous powder 
          of 93-95% purity with a pungent odour and has m.p. 160-170°C. 

    1.3.2 Solubility - Practically insoluble in water (<O.5 mg/l) and 
          petroleum oils.  Solubility between 10 and 100 mg/i in common 
          organic solvents. 

    1.3.3 Stability - Stable at normal temperature except under alkaline 
          conditions.  Decomposes at about 100°C, slowly in dry and rapidly 
          in moist air.  Rapidly decomposed in human blood; the half life 
          at an initial concentration of 100 µg/ml is 0.9 minutes.  
          Compatible with most non-alkaline pesticides. Non-corrosive but 
          forms corrosive decomposition products. 

    1.3.4 Vapour pressure (volatility) - The pure compound has a vapour 
          pressure of 1 x 10-5 torr at 25°C but the technical product is 
          stated to be much higher. 


          
    1.4 AGRICULTURE, HORTICULTURE AND FORESTRY

    1.4.1 Common formulations - 500 and 830 g/kg wettable powders; 400 g/l 
          aqueous suspension; 35-100 g/kg dusts for field use; 600-750 g/kg 
          dust for seed treatment.  There are FAO specifications for dusts 
          and wettable powders. 

    1.4.2 Susceptible pests - Wide range of fungi, especially scab. rot and 
          leaf spot of many fruits.  Probably recommended for more diseases 
          on deciduous top fruit than any other fungicide.  Gives no 
          control of powdery mildews and little of rusts.  No insecticidal 
          or acaridal activity.  Has been proposed for ringworm control in 
          animals. 

    1.4.3 Use pattern - Pre-harvest protective treatment, particularly of 
          foliage, on many fruits, vegetables and ornamentals, and on turf.  
          Most important uses include control of apple, pear and peach 
          scab; apple rot; pear leaf spot and sooty blotch; brown rot of 
          cherry, peach and plum; leaf spot of sweet cherry.  Rates of use 
          are usually 10 g/l as a high-volume spray or about 3 kg/ha. 

          Used for rot control in stored potatoes, as post-harvest dip for 
          fruit and vegetables and as a pre-packing spray for packing 
          boxes.  It is widely used as a seed dressing, particularly on 
          peas, and as a pre-planting soil fungicide. 

          Has been used as a growth regulator to increase size of oranges 
          and tangeloes. 

    1.4.4 Unintended effects - Generally non-phytotoxic but injury to 
          D'Anjou and Bosc pears, and to Red Delicious, Winesap and some 
          other apple varieties has been reported.  It is incompatible with 
          oil and may cause injury if applied after a summer oil 
          combination.  There is a possibility of taint if used on fruit 
          for processing. 

            
    1.5   PUBLIC HEALTH PROGRAMME - None.

            
    1.6    HOUSEHOLD USE - Used in home gardens.

            
    2.    TOXICOLOGY AND RISKS

    2.1   TOXICOLOGY - MAMMALS

    2.1.1 Absorption route - Absorbed by the gastrointestinal tract, no 
          information on whether the compound can be absorbed by inhalation 
          or dermally. 

    2.1.2 Mode of action - Not known.

    2.1.3 Excretion products - Captan is rapidly hydrolysed and probably 
          excreted as tetrahydrophthalimide, tetrahydrophthalamic acid and 
          tetrahydrophthalic acid.  The fate of the trichloromethylthio-
          portion of the molecule is uncertain; the chlorine atoms appear 
          to be liberated as chloride ions. 

    2.1.4 Toxicity, single dose

          Oral: LD50 rat 9000-12 500 mg/kg

          Dermal: LD50 not known

          Inhalation: No information

          Most susceptible species: Not known

    2.1.5 Toxicity, repeated doses

          Oral: In dogs fed a maxim= of 300 (mg/kg)/day in gradually 
          increasing doses for 60 weeks, there was no evidence of systemic 
          toxicity and no gross or histopathological changes in tissues due 
          to treatment, nor were there any significant changes in 
          haematological or biochemical findings. 

          Dermal: No information.

          Inhalation: No information.

          Cumulation of compound: The compound is rapidly metabolized and 
          does not accumulate in body tissues. 

          Cumulation of effect: No information.

    2.1.6 Dietary studies

          Short-term: Rats were fed increasing doses of captan up to a 
          maximum level of 10 000 mg/kg diet (500 (mg/kg)/day) for 13 
          weeks.  Levels of 5000 and 10 000 ppm (250 and 500 mg/kg/day) 
          caused growth retardation. 

          Long-term: In a two-year feeding study, rats were fed 1000 and
          5000 mg/kg of captan (50 and 250 (mg/kg)/day).  The only effect 
          was reduced weight-gain. 

    2.1.7 Supplementary studies of toxicity

          Reproduction: In a three-generation rat reproduction study, the 
          only effect at 1000 mg/kg diet (50 (mg/kg)/day) was slightly 
          lowered lactation index in the third generation. There was no 
          effect at 500 mg/kg (5 (mg/kg)/day). 

          Teratogenicity:

          Rabbit: No malformed foetuses were observed from rabbits given up 
          to 75 mg/kg of captan orally on days 6-18 of gestation.  The same 
          was true when the metabolite tetrahydrophthalimide given at 75 
          mg/kg daily on days 6-16 of gestation. 

          Hamster: No increase in abnormal foetal effects was observed in 
          pregnant hamsters receiving up to 100 mg/kg of captan daily on 
          days 1-15 of gestation.  There was, however increased foetal 
          resorption at this level. 

          Monkey: There were no foetal malformations from monkeys given 
          up to 75 mg/kg on days 21-34 of gestation.  In another study 
          there was increased foetal mortality at 25 mg/kg on days 22-32 of 
          gestation but no abnormalities. 

          Mutagenicity:

          Mouse: Dominant lethal mutations were not induced from a 
          maximum intraperitoneal injection of 7 mg/kg to male mice. 

          Carcinogenicity:

          Mouse: 560 mg/kg diet (84 (mg/kg)/day) of captan for 18 months 
          did not result in tumour-increase in mice. 

          Rat: There was no increase in tumour frequency when rats were 
          fed 5000 mg/kg (250 (mg/kg)/day) of captan for two years or 
          10 000 mg/kg (500 (mg/kg)/day) for 24 weeks. 

    2.1.8 Modification of toxicity: The acute toxicity of captan was 
          increased by a factor of 26 when rats were fed a low protein 
          diet. 

            
    2.2   TOXICOLOGY - MAN

    2.2.1 Dangerous doses

          Single: Not known.

          Repeated: Not known.

    2.2.2 Observations of occupationally exposed workers - There is some 
          evidence that captan can be irritating to the skin, eyes, nose 
          and mouth. 

    2.2.3 Observations on exposure of the general population - No 
          information. 

    2.2.4 Observations of volunteers - No information

    2.2.5 Reported mishaps - No information.  No reports of human poisoning 
          have been located. 

            
    2.3   TOXICITY TO NON-MAMMALIAN SPECIES - The entries in these sections 
          are intended to draw attention to special risks and to give 
          warnings of any needs for special precautions. 

    2.3.1 Fish - Toxic to fish.

    2.3.2 Birds - Low toxicity.

    2.3.3 Other species - Slight toxicity to bees has been reported in 
          field tests. 

            
     3.    FOR REGULATORY AUTHORITIES - RECOMMENDATIONS ON REGULATION OF 
          COMPOUND

    3.1   RECOMMENDED RESTRICTIONS ON AVAILABILITY

          (for definition of categories, see introduction)

          All formulations Category 5

            
    3.2   TRANSPORTATION AND STORAGE

          All formulation - Should be transported or stored in clearly 
          labelled leak-proof containers out of reach of children, away 
          from food and drink. 

                
    3.3   HANDLING

          All formulations - Captan may be irritating to the skin, eyes, 
          nose and mouth.  Avoid inhaling dust. 

            
    3.4   DISPOSAL AND/OR DECONTAMINATION OF CONTAINERS

          All formulations - Containers may be decontaminated (for method 
          see para. 4.3 in part 4).  Decontaminated containers should not 
          be used for food and drink.  Containers that are not 
          decontaminated should be burned or should be crushed and buried 
          below topsoil.  Care must be taken to avoid subsequent 
          contamination of water sources. 

            
    3.5   SELECTION, TRAINING AND MEDICAL SUPERVISION OF WORKERS

          All formulations - Pre-employment or periodic medical 
          examinations not necessary.  Warning of workers to minimize 
          contact essential. 

            
    3.6   ADDITIONAL REGULATIONS RECOMMENDED IF DISTRIBUTED BY AIRCRAFT - 
          No special regulations recommended. 


            
    3.7   LABELLING - Minimum cautionary statement: "Captan is a fungicide 
          of very low toxicity; however the dust may be irritating to the 
          eyes, nose or mouth". 

            
    3.8   RESIDUES IN FOOD

    3.8.1 Maximum residue levels - The Joint FAO/WHO Meeting on Pesticide 
          Residues has recommended maximum residue levels.

            
    4.    PREVENTION OF POISONING IN MAN AND EMERGENCY AID

    4.1   PRECAUTIONS IN USE

    4.1.1 General - Captan is a sulfenimide fungicide of very low toxicity 
          which is absorbed from the gastrointestinal tract and rapidly 
          metabolized.  It does not accumulate in tissues. 

    4.1.2 Manufacture and formulation - T.L.V. 5 mg/m3 (ACGIH).  Vapour 
          and dust should be controlled by mechanical means.  Protective 
          equipment for skin and respiratory protection is desirable. 

    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 and gloves should be worn.  
          Mixing, if not mechanical, should always be carried out with a 
          paddle of appropriate length. 

          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 captan and associated with its application 
          should observe the precautions described above in 4.1.3 tinder 
          "mixers and applicators". 

    4.1.5 Other populations likely to be affected - None.


    4.2   ENTRY OF PERSON INTO TREATED AREAS - Persons may enter treated 
          areas immediately. 
                

            
    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.  Hands should be protected during this work.  
          An additional rinse should be carried out with 5% sodium 
          hydroxide solution which should remain in the container 
          overnight.  Decontaminated containers should not be used for food 
          and drink.  Spillage should be removed as much as possible 
          followed by washing the area with 5% sodium hydroxide solution 
          and then rinsing with large quantities of water. 

    4.4   EMERGENCY AID 

    4.4.1 Early symptoms of poisoning - As there are no reports of 
          poisoning with captan, the early symptoms are not known. There 
          may be some irritation to the skin, eyes, nose and mouth. 

    4.4.2 Treatment before person is seen by a physician, if these symptoms 
          appear following exposure - If excessive irritation occurs or if 
          abnormal symptoms appear following exposure to captan the person 
          should stop work, remove contaminated clothing and wash the 
          affected skin with soap and water, if available, and flush the 
          area with large quantities of water.  If swallowed, vomiting 
          should be induced. 

            
    5.    FOR MEDICAL AND LABORATORY PERSONNEL

    5.1   MEDICAL DIAGNOSIS AND TREATMENT IN CASES OF POISONING

    5.1.1 General information - Captan is a sulfenimide fungicide of very 
          low toxicity which is absorbed from the gastrointestinal tract.  
          It is rapidly metabolized and probably excreted as 
          tetrahydrophthalimide, tetrahydrophthalamic acid and 
          tetrahydrophthalic acid.  It does not accumulate in the body 
          tissues. 

    5.1.2 Symptoms and signs - There may be some irritation to the skin, 
          eyes, nose and mouth.  As there are no reports of poisoning with 
          captan the symptoms are not known, but gastrointestinal 
          irritation and possible renal damage might be expected from 
          animal experiments. 

    5.1.3 Laboratory - There are no practical laboratory methods; levels of 
          the metabolites tetrahydrophthalimide, tetrahydrophthalimic acid 
          and tetrahydrophthalic acid in blood and urine may give an 
          indication of the degree of absorption of captan. 

    5.1.4 Treatment - If a large quantity of captan has been ingested, 
          vomiting should be induced, or if the induction fails, gastric 
          lavage should be performed using 5% sodium bicarbonate solution, 
          if available.  If there is skin irritation, the skin should be 
          washed with soap and water.  If the compound has entered the 
          eyes, they should be washed with isotonic saline.  Further 
          treatment should be symptomatic. 

    5.1.5 Prognosis - Not known.

    5.1.6 References of previously reported cases - No information; 
          poisoning by captan has not been reported. 


    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 - The colorimetric determination 
          of residues of captan in fruit and vegetables is described by the 
          AOAC (1965), and the application of the method to other crops, 
          meat, milk and blood is reviewed by Ospenson et al. (1964). 

          Captan can be determined in fruits by the gas-chromatographic 
          method of Baker & Flaherty (1972).  This distinguishes between 
          captan, folpet, and captafol, and should be suitable for 
          regulatory purposes. 

          Zweig & Sherma (1972) give references to GC methods for captan 
          and recommend the procedure of Pack (1967) (originally applied to 
          difolatan) for crops. 

    5.3.2 Other tests in cases of poisoning - None.


                                     REFERENCES

    AOAC (1965) Official methods of analysis of the AOAC, 10th ed., 
           p. 390 

    Baker, P. B. & Flaherty, B. (1972) Fungicide residues.  Part II. The 
          simultaneous determination of residues of folpet, captan, and 
          captafol in selected fruits by the gas chromatography, Analyst, 
          97, 713 

    Ospenson, J. N. et al. (1964) In:  Zweig, G., ed., Analytical methods 
          for pesticides, plant growth regulators and food additives, 
          Vol. III, New York and London, Academic Press, p. 11 

    Pack, D. E. (1967) ibid., Vol.  V, p. 299

    Zweig, G. & Sherma, J. (1972) ibid., Vol.  VI, p. 548





     

See Also:
        Captan (IARC Summary & Evaluation, Volume 30, 1983)
        Captan (ICSC)
        Captan (PIM 098)