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    TRICHLORFON      JMPR 1975

    Explanation

         Trichlorfon was evaluated by the Joint Meeting in 1971 (FAO/WHO,
    1972).

         Arising out of the list of requirements in the report of the 1971
    Joint Meeting (FAO/WHO, 1972) additional information became available
    on residues from supervised trials on lettuce (outdoors) and spinach
    (outdoors and under glass).

         A temporary ADI was estimated in 1971 and temporary tolerances
    were recommended. Based on inconclusive findings in long-term studies
    a temporary ADI of 0-0.01 mg/kg per day was estimated.

         At the eighth Session of the Codex Committee on Pesticide
    Residues (Alinorm 76/24) the delegations of the Netherlands and Israel
    expressed the opinion (para. 168) that the proposed temporary
    tolerance of 0.1 mg/kg for tomatoes was too low to cover residues
    resulting from good agricultural practice in their countries. The
    Joint Meeting was requested to re-evaluate the limit, with the help of
    data to be provided. Limited data have been received from the
    Netherlands.

         The delegation of the Netherlands also requested (para. 169) that
    the Joint Meeting should propose tolerances for pears, currants,
    mushrooms, spinach, melons (under glass), cucumbers (under glass) and
    bell peppers (under glass). Governments were asked to send any data in
    their possession. No data on any of these crops except spinach have
    however been received.

         This monograph addendum includes an evaluation of the new data on
    toxicology and on lettuce, spinach and tomatoes, and a re-evaluation
    of data already available on cereals in the light of current use
    patterns.

    EVALUATION FOR ACCEPTABLE DAILY INTAKE

    TOXICOLOGICAL STUDIES

    Special studies on acute administration

         Chicken

         Groups of 6, 10, 6 broilers were given by gastric intubation, a
    single administration of 40, 60 and 80 mg/kg bw trichlorfon in 1%
    aqueous solution. ChE activity and blood biochemical parameters
    (alkaline phosphatase, serum proteins, uric acid and electrolytes)
    were examined. Plasma ChE depression reached its maximum (8.4-10.8% of
    its initial value) four hours after administration and activity

    recovered to 80% after seven days at all levels of administration;
    decreased alkaline phosphatase activity, slight diminution in serum
    proteins (total and fractions) but no noticeable change in level of
    Na, K, Ca, Mg were observed. Onset of symptoms was rapid (20-30
    minutes after administration) and included respiratory failure, clonic
    convulsion, prostration, loss of appetite, salivation and diarrhoea.
    No morphological changes were observed in organs at autopsy of dead
    animals (Lazarov and Magat, 1975).

    Special studies on carcinogenicity

         Groups of rats and mice were administered trichlorfon at various
    routes, doses and periods ranging from six weeks to the end of the
    animal's life. In two studies (Gibel et al., 1971 and 1973) the
    authors concluded that hepatotoxic, haematotoxic and carcinogenic
    effects were observed, The following is a summary of methodology
    employed in both studies.


                                                                             

                                                                 (Weekly)
                                              Duration            Dose
    Year    Species   Number         Route    of dosing          (mg/kg)
                                                                             

    1971    Rat       40 M & 40 F    Oral     Not specified     3 × 30 mg/kg

            Rat       40 M & 40 F    S.C.     Not specified     2 × 30 mg/kg

            Mice      10 M & 10 F    Dermal   5 months          3 ×

    1973    Rat       20 M & 20 F    Oral     Not specified     2 × 15 mg/kg

            Rat       20 M & 20 F    I.M.     Not specified     2 × 15 mg/kg

            Mice      10 M & 10 F    Dermal   6 weeks           2 ×

                                                                             


         The 1973 treatments caused hyperplasia of the blood forming
    system of bone marrow and extraosseal metaplasia in the liver and
    spleen. In addition, the authors diagnosed myeloproliferation and
    partly extraosseal myeloid metaplasia. The authors in addition
    describe extensive hepatotoxicity and carcinogenic response in both
    studies.

         The evaluation of these papers is difficult as doses or duration
    are not specified in all cases. The hepatotoxic effects ranging from
    fibrosis to cirrhosis in rats and mice are not consistent with
    findings in other long-term studies in rats and dogs. Dermatological
    disturbances are difficult to comprehend, especially in light of their
    occurrence when dimethoate was also used in another trial.
    Leukaemia-like toxic signs have not been demonstrated with dimethoate
    and in general, leukaemia is difficult to produce in animal
    experiments.

         With reference to the carcinogenic response, the authors suggest
    that benign tumours are a reflection of severe hepatotoxicity and the
    mean survival time of mice was longer in the 1971 study in which
    trichlorfon was administered at a higher dose for a greater period of
    time. In addition there was no correlation between dose and tumour
    frequency in this dermal study. The description of localization of
    tumours occurring in the study gives no indication of organotrophy. In
    addition, data reported in the 1971 Evaluation suggesting tumour
    formation in mammary glands was not substantiated in these studies.
    Basically, these two studies are contradictory in their own right of
    previous studies and are in addition difficult to fully interpret. It
    is difficult if not impossible to compare these studies with
    previously reported long-term studies showing no carcinogenic,
    hepatotoxic or haemotoxic response. In light of these difficulties and
    in inconsistencies in data reported for dimethoate, little
    significance is given to the above referenced studies in evaluating
    the ADI.

    Special studies on neurotoxicity

         Groups of hens (number of birds/group not specified) were
    administered trichlorfon orally or by intraperitoneal injection at
    dose levels ranging from 25-100 mg/kg (acute LD50 = 75 mg/kg) and
    examined for signs of delayed neurotoxicity. No ToCP-like signs of
    delayed neurotoxicity were observed (Kimmerle and Loser, 1974).

    Short-term studies

         Rat

         Morphological changes in the lung, kidney and liver were reported
    following continuous inhalation exposure to trichlorfon at high
    levels. Exposure to 20 mg/l and above concentrations for 90 days
    resulted in bile duct hypertrophy, kidney changes, thyroid changes and
    capillary enlargement of the interalveolar membrane of the lung. At 20
    mg/l no effects were reported (Bonashevakaya and Tabakova, 1972).

         Rats were administered trichlorfon orally at a daily dose of 8.5
    mg/kg body weight in combination with carbon tetrachloride
    administered three times/week for nine months (dose stated to be 0.1
    mg/100 g of a 25% solution in sunflower seed oil). The combined effect
    led to "more advanced and stable destructive and dystrophic changes in
    the liver and enhanced the cirrhotic process". Liver metabolism was
    disrupted (Rodionov and Voronina, 1973).

         Subacute poisoning to rats (300 mg/kg/day) for five days resulted
    in significant changes observed histologically. All changes as were
    described were not specific and might appear in many cases of acute
    poisoning. Biochemical lesions included cholinesterase depression and
    succinate dehydrogenase and cytochrome oxidase inhibition in brain,
    liver, kidney and heart (Karmelov, 1973).

         Chicken

         A daily dose of 5 mg/kg bw trichlorfon in 1% aqueous solution was
    given by gastric intubation to a group of 5 broilers for 14 days,
    after which period the dose was increased to 20 mg/kg for 14
    additional days; to another group of 5 broilers, a daily dose of 10
    mg/kg bw was given for 28 days. In the 5-20 mg/kg group ChE activity
    after reaching a low peak at day 7, increased almost to its initial
    value at day 14, after which period it decreased to 62% of its initial
    value at day 28; in the 10 mg/kg group ChE activity after a slight
    increase at day 7, declined gradually until day 28. Alkaline
    phosphatase declined in both groups; serum proteins showed
    insignificant variations and no changes were observed in electrolyte
    levels; body weight gain was depressed at 20 mg as compared to 10 mg.
    Clinical signs (respiratory, digestive and motor disturbances) were
    more accentuated in the higher level group and more marked at day 3 to
    5 of treatment (Lazarov and Magat, 1975).

         Calf

         Calves were fed trichlorfon for 3 months at dosage levels of
    7.87, 15.9 and 41.25 ppm in the diet. No effects were noted at the low
    dose level while at 15.9 ppm cholinesterase depression and generalized
    histopathological signs were noted. Death occurred at the high level
    (summary reviewed from abstract, no details are available) (Yasnova et
    al., 1971).

    COMMENTS

         Trichlorfon was reviewed in 1971, at which time a temporary ADI
    was estimated to be 0-0.01 mg/kg per day based on both long-term
    animal studies and on extensive observations in man. There was serious
    consideration given to three long-term rat studies that were basically
    inconclusive with respect to the carcinogenic potential of
    trichlorfon. Since that time some new work was reported again
    reflecting a carcinogenic potential. A complete evaluation of the
    conflicting research data was made.

         The data that have come to light since the 1971 meeting do not
    allow a further interpretation of the confusing observations with
    respect to long-term rat studies showing a tumourigenic potential on
    two studies, no such effect in a third study (in rats) and no-effect
    on tumour formation in dogs. Although, as there is little indication
    that the requested work on rats is to be forthcoming a current study
    with mice has been reported to be in progress. In addition, some
    concern was expressed of the mechanism by which trichlorfon is
    transformed to dichlorvos. The potential intermediates formed in the
    intramoleculan rearrangement might include carbanion or free radical
    formation which may have no mutagenesis or carcinogenesis problems.

         In the light of the extensive experience of use in man and with
    the expectation of a new carcinogenesis study, the temporary ADI was
    extended although at a lower figure.

    TOXICOLOGICAL EVALUATION

    Level causing no toxicological effect

         Rat: 50 ppm in the diet equivalent to 2.5 mg/kg body weight.

         Dog: 50 ppm in the diet equivalent to 1.25 mg/kg body weight.

    ESTIMATE OF TEMPORARY ACCEPTABLE DAILY INTAKE FOR MAN

         0-0.005 mg/kg body weight.

    RESIDUES IN FOOD AND THEIR EVALUATION

    RESIDUES FROM SUPERVISED TRIALS

         See Table 1.

         Each graph presents a plot of all residue values recorded in
    trials in the Federal Republic of Germany, Finland and the United
    States of America; a line is drawn based on the maximum values found
    on the respective days after treatment, omitting one experiment on
    lettuce in the United States of America showing abnormal figures.

    APPRAISAL

         New data from supervised trials confirmed the validity of the
    recommendations for temporary tolerances made in 1971 with the
    exception of that for tomatoes. Extensive data from a number of
    countries reflecting trials carried out over many years provided an
    adequate basis for recommendations with respect to trichlorfon
    residues on lettuce and spinach as required by the 1971 Meeting. New
    data on residues in tomatoes were limited, but were considered
    sufficient to justify the increased temporary maximum residue limit
    recommended below.
        TABLE 1.  Residues of trichlorfon resulting from supervised trials

                                                                                                                                               

                                              Application              Residue (mg/kg) intervals (days) after application

                                              Rate kg
     Crop           Country      Year   No.   a.i./ha   Formulation    0        1        3/5      7        9/12      14        21        Ref.
                                                                                                                                               

    Lettuce
     (outdoors)

     leaf-lettuce   Finland      1972   1     1.2        wp 80%        33.5              2.6      0.61               0.21      0.03      11, 17
                    Finland      1972   1     1.2        wp 80%        26.4              1.3      0.23               0.26      0.02      11, 17

     leaf-lettuce   U.S.A.       1961   2     1.2        wp 50%                 6.3      1.3      <0.1              <0.1                 12
                                 1961   2     1.2        wp 50%                 3.5      1.1      <0.1              <0.1                 12
                                 1961   2     1.2        wp 50%                 2.7      0.4      0.2                                    12
                                                                                (0.8-    (<0.1-   (<0.1-
                                                                                3.8)     0.8)     0.4)
                                 1962   2     1.2        wp 50%                 97.6     9.2      6.0                3.9                 12

     head-lettuce   Finland      1972   1     1.2        wp 50%        22.8              1.5      0.31               0.04      0.01      13, 17
                                 1972   1     1.2        wp 50%        31.2              1.1      0.17               0.06      <0.01     13, 17

     head-lettuce   Fed. Rep.    1972   1     0.75       E.C. 50%      8.1      1.8      0.54     0.41     0.20      <0.05     <0.05     14
                    of Germany
                                 1972   1     0.45       E.C. 50%      5.8      1.8      0.22     0.09     <0.05     <0.05     <0.05     14
                                 1972   1     0.45       E.C. 50%      4.8      4.3      0.27     <0.05    <0.05     <0.05    <0.05     14
                                 1972   1     0.75       E.C. 50%      15.9     4.6      0.21     0.08     0.14      <0.05     <0.05     14

     lettuce        U.S.A.       1957   1     0.6        wp 50%        1.6      0.8      0.3      0.7                0.03      0.2       15
                                 1958   1     1.2        wp 50%        0.8      0.8      0.6      <0.1               0.03                15
                                 1959   1     0.6        wp 50%                 1.8               0.3                0.1       <0.1      15
                                                                                (2 days)
                                 1959   6     1.2        wp 50%                                                      <0.1                16
                                        7     1.2        wp 50%                                            0.2                           16
                                        5     1.2        wp 50%                                            0.5                           16

    TABLE 1.  (Cont'd.)

                                                                                                                                               

                                              Application              Residue (mg/kg) intervals (days) after application

                                              Rate kg
     Crop           Country      Year   No.   a.i./ha   Formulation    0         1/2      3/4      7/8      10/11     12/13     14/15     Ref.
                                                                                                                                               

    Spinach         Netherlands  1957   1     1.1        wp 50%        27.4     3.8      2.2      0.85     0.6       0.3       0.3       1
    glasshouse                                                         (23.3-    (2.9-    (1.2-    (0.4-    (0.2-     (0.2-     (0.1-
                                                                       33.3)     5.5)     3.4)     1.3)     0.9)      0.4)      0.5)

                    Netherlands  1957   1     1.1        wp 50%        3.0      2.0      0.55     0.4      0.2       0.1                 1
                                                                      (1.9-     (1.2-    (0.4-    (0.25-   (0.2-     (0.06-
                                                                       4.5)      3.1)     0.8)     0.5)     0.3)      0.1)

    under frames    Fed. Rep.    1965   1     0.75       wp 50%                          4.4               2.4                 1.6       2
                    of Germany

                    Fed. Rep.    1968   1     0.75       wp 50%        >30     21.4     5.2      1.2      2.2                 0.25      2
                    of Germany

    TABLE 1.  (Cont'd.)

                                                                                                                                               

                                              Application              Residue (mg/kg) intervals (days) after application

                                              Rate kg
     Crop           Country      Year   No.   a.i./ha   Formulation    0        1/2      3/4      7/8      10/11    12/13     14/15     Ref.
                                                                                                                                               

    Spinach         Netherlands  1962   1     0.5        wp 50%       6.0       2.6      1.3      0.35     0.25                         3
     outdoors                                                         (5.7-     (1.2-    (0.8-    (0.1-    (0.2-
                                                                      6.1)      2.7)     2.1)     0.6)     0.3)

                    Netherlands  1962   1     0.63       wp 50%       1.9      0.8      0.25     0.15     0.10                          3
                                                                      (1.8-    (0.4-    (n.d.-   (0.1-    (n.d.-
                                                                      2.2)     1.1)     0.6)     0.2)     0.2)

                    Netherlands  1963   1     1.9        wp 50%       0.95              0.18     0.08     n.d.                          4
                                                                      (0.5-             (0.05-   (n.d.-
                                                                      1.4)              0.3)     0.1)

                    Netherlands  1963   1     0.70       wp 50%       1.2      0.2      0.2      0.01     0.03                          4
                                                                      (0.6-    (0.2-    (n.d-    (n.d.-   (n.d.-
                                                                      1.4)     0.3)     0.4)     0.03)    0.07)

    Spinach         Fed. Rep.    1965   1     0.75       wp 50%                         2.0      1.6      0.7                 0.35      5
    outdoors        of Germany

                    Fed. Rep.    1965   1     0.75       wp 50%                         0.4      0.02                                   5
                    of Germany

                    Switzerland  1967   1    ca. 1.5     wp 80%                         19.8     1.8                0.15                6

                    Fed. Rep.    1968   1     0.75       wp 50%       34       6.0      0.85     0.15                                   7
                    of Germany                                                          (5 days)

                    Fed. Rep.    1968   1     0.75       wp 50%       33                1.7      0.3      0.08                          7
                    of Germany

    TABLE 1.  (Cont'd.)

                                                                                                                                               

                                              Application              Residue (mg/kg) intervals (days) after application

                                              Rate kg
     Crop           Country      Year   No.   a.i./ha   Formulation    0        1/2      3/4      7/8     10/11     12/13     14/15     Ref.
                                                                                                                                               

    Spinach         Fed. Rep.    1968   1     0.75       wp 50%        >30      13.2     5.6      1.0      1.0                 0.35      7
    outdoors        of Germany

                    Canada       19     2     1.1        wp 50?                          0.6      0.2                          n.d.      8

                    Canada       19     2     1.1        wp                              39       3.5                          n.d.      8

                    U.S.A.       19     2     1.1        wp                              11.2     0.3                          0.3       9

                    U.S.A.       19     2     1.1        wp                                       0.9                          0.4       9

                    U.S.A.       19     2     1.1        wp                              1.8      0.2                          n.d.      9

                                                                       0        3

    Tomato          Netherlands  1973   1     1.2        wp 50%                 <0.03                                                  10
    glasshouse                                                                  (<0.03-
                                                                                0.03)

                    Netherlands  1973   1     1.2        wp 50%                 0.10                                                    10
                                                                                (0.08-
                                                                                0.13)
                                                                                                                                               

     n.d. = not detectable.

    Methods of residue analysis used to obtain the data of Table 1 and Figure. 1-4

    Ref. 1, 3, 4             Non-specific method for organophosphorous compounds; spectrofotometric determination as 
                             phosphomolybdate-quinaldine-red complex. Limit of detection about 0.01-0.03 mg/kg ("n.d." in Table 1 refers
                             to a limit of 0.03 mg/kg).

    TABLE 1.  (Cont'd.)

                                                                                                                                               


    Ref. 2, 5, 6, 7, 8, 9    Method of analysis not quoted.
                             Limit of detection 0.02 mg/kg.

    Ref. 10                  TLC; detection by cholinesterase inhibition.
                             Limit of detection 0.03 mg/kg.

    Ref. 11, 13              GLC P detector.
                             Limit of detection 0.01 mg/kg.

    Ref. 14                  GLC P detector.
                             Limit of detection 0.05 mg/kg.

    Ref. 12                  Method of chemagro (report 8992, January 1962).
                             Limit of detection 0.1 mg/kg.

    Ref. 15                  Method of analysis not quoted.
                             Limit of detection 0.1 mg/kg.
    

         No new information has become available to indicate residue
    levels in oats as requested by the 1971 Joint Meeting (FAO/WHO, 1972).
    However, re-evaluation of the original data, in the light of the
    current use pattern, made it clear that a maximum residue limit of 0.1
    mg/kg for raw cereals including maize was more appropriate than the
    separate tolerances for barley and maize, 0.1 mg/kg, and wheat, 0.2
    mg/kg, previously recommended.

    RECOMMENDATIONS

         In addition to recommendations made in 1971, the following
    temporary maximum residue limits are recommended for lettuce and
    spinach. The temporary limit for residues in raw cereals replaces
    recommendations previously made for barley, wheat and maize, and that
    for tomatoes replaces the previously recommended temporary tolerance
    of 0.1 mg/kg.

    TEMPORARY MAXIMUM RESIDUE LIMITS

                                                                        

                                                          Pre-harvest
                                                          intervals on
                                            Limit,        which
    Commodity                               mg/kg         recommendations
                                                          are based
                                                                        

    Raw cereals, including maize            0.1           21-30

    Lettuce                                 0.5           Outdoors 14-21
                                                          Glasshouse 21-28

    Spinach                                 0.5           Outdoors 14-21
                                                          Glasshouse 21-28

    Tomatoes                                0.2           Outdoors 14
                                                          Glasshouse 3
                                                                        


    NATIONAL TOLERANCES AND PRE-HARVEST INTERVALS REPORTED TO
    THE MEETING

         Officially recommended pre-harvest or pre-slaughter intervals
    reported. to the Meeting are listed in Table 2. National tolerances
    reported to the Meeting are given in Table 3.

    TABLE 2.  Officially recommended pre-harvest and pre-slaughter intervals

                                                                             

                                                                  Interval
     Country           Crop or animal                               days
                                                                             

    Brazil            all crops                                    4

    Democratic        fruits and vegetables, field crops           7
     Rep. of
     Germany          cherries, strawberries                       3

                      crops used for the production of             21
                      baby-foods

    Federal           pome fruits                                  10
     Republic of
     Germany          stone fruits, beans, black radish,           14
                      garden beets, leafy vegetables, leek,
                      onions, peas, radish

                      sugar and fodder beets                       28

    France            all crops                                    7

    Hungary           vegetables                                   14

                      other crops, including potatoes              10

    Italy             maize                                        10

    Japan             cucumbers, egg plants                        3

                      apples, pears, cabbage, china cabbage,       7
                      cauliflower, Japanese radish, turnips,
                      pumpkins, musk melons, watermelon,
                      Japanese cantaloupe

                      grapes, potatoes, sweet potatoes, rice,      14
                      sugar beets, tea

    Netherlands       pome and stone fruits, gooseberries, red     10
                      and black currants, brassicas, garden
                      beets

                      Brussels sprouts, spinach                    4

                      bell peppers, cucumbers, melons,            3 weeks.
                      tomatoes, other glasshouse vegetables       Use not
                      except gherkins, leaf-celery, parsley       permitted
                       period 1/3 - 1/11
                              1/11 - 1/3

    TABLE 2.  (Cont'd.)

                                                                             

                                                                  Interval
     Country           Crop or animal                               days
                                                                             

    New Zealand       all crops                                    14

                      tomatoes for canning                         1

    Poland            vegetables including root vegetables,        10
                      agricultural crops, pulses

                      fruits except raspberries and                10
                      strawberries

                      tomatoes                                     3

    South Africa      beans                                        5

                      coffee, rape seed, sweet potatoes            7

                      pome and stone fruit, citrus fruit,          10
                      cucumbers, passion fruit

                      maize                                        10

                      alfalfa (fresh), clover-fodder               2

    U.S.A.            lima beans, tobacco                          3

                      clover                                       7

                      alfalfa, cotton                              7-141

                      artichokes, beans (dry, snap), bean          14
                      vines, cowpeas, pumpkins, sugar beet
                      roots

                      barley, Brussels sprouts, cabbage,           21
                      cauliflower, flax, oats, peppers,
                      tomatoes, wheat

                      beets, carrots, collards, corn, lettuce,     28
                      sugar beet tops (used for feeding
                      purposes)

                      beef cattle, non-lactating dairy cattle      14-21
                                                                             

    1  Depending on dosage and formulation used.

    TABLE 3.  National tolerances, established or considered, reported
              to the Meeting

                                                                             

                                                                  Tolerance
     Country           Commodity                                    mg/kg
                                                                             

    Argentina         bananas                                      0.2

                      carrots                                      0

                      wheat, maize (kernels), coffee beans,        0.3
                      sugar cane

                      cabbage, Savoy cabbage, cauliflower,         0.75
                      lettuce, peanut, pecan nut, potato,
                      spinach, tomato

                      barley, rice, maize fodder, cottonseed       0.75

                      alfalfa (fresh), cereal fodder, clover       2
                      (fresh), peanut fodder, sugar beet
                      leaves

                      alfalfa fodder, clover fodder                12

    Australia         fruits, vegetables, dried fruits             2

    Belgium           fruit, vegetables except potatoes            0.5

    Brazil            fruit, vegetables, agricultural crops        0.5
     (proposed)
                      meat and milk                                0.001

    Canada            artichokes, bananas, beans, beets,          Negligible
                      Brussels sprouts, cabbage, carrots,         residue
                      cauliflower, collard, kale, lettuce
                      maize, peppers, rape seed, rutabagas,
                      salsify, spinach, sugar beets,
                      tomatoes, turnips, beef cattle

    Czechoslovakia    fruits, vegetables                           1

    Democratic        pome and stone fruits, red and black         1.0
     Rep. of          currants, strawberries, citrus fruits,
     Germany          nuts

                      brassicas, leafy vegetables, root            1.0
                      vegetables, pulses, fruits of
                      vegetables

    TABLE 3.  (Cont'd.)

                                                                             

                                                                  Tolerance
     Country           Commodity                                    mg/kg
                                                                             

                      cereals, potatoes                            0.02

                      onions                                       0.02

    Democratic        meat, fish, fat of animal and plant          0.02
     Rep. of          origin, eggs, milk, crops used for
     Germany          production of baby-food

    Federal           fruits and vegetables                        0.5
     Republic of
     Germany          other products of plant origin               0.1

    France            fruit and vegetables                         0.5

    Hungary           fruits, vegetables, agricultural crops       1

    Japan             fruits, vegetables, potatoes, rice, tea      0.5

    Netherlands       fruits and vegetables, except potatoes       0.5

    New Zealand       fruits, vegetables, agricultural crops       0.1

    Poland            fruits and vegetables                        0.5

    South Africa      fruits, vegetables, agricultural crops       2

    U.S.A.            range grass, range grass hay                 240

                      hay of alfalfa, clover and pasture grass     90

                      alfalfa, clover and pasture grass            60

                      forage of barley, oats, and wheat            50

                      corn fodder and forage                       30

                      lima bean vines, lima bean vine hay,         12
                      lima beans, sugar beet tops

                      peanut vine hay and hulls                    4

                      bananas (of which not more than 0.2          2
                      parts per million will be present in
                      the pulp after the peel is removed)

    TABLE 3.  (Cont'd.)

                                                                             

                                                                  Tolerance
     Country           Commodity                                    mg/kg
                                                                             

                      staw of barley, flax, oats and wheat,        1
                      vines of beans and cowpeas

                      artichokes, barley (grain), beans            0.1
                      (dried), beets, Brussels sprouts,
                      cabbage, carrots, cauliflower, citrus
                      fruit, collards, corn grain (including
                      popcorn), fresh corn including sweet
                      corn (kernels plus cob with husk
                      removed), cottonseed, cowpeas, flaxseed,
                      lettuce, meat, fat and meat byproducts
                      of cattle, goats, horses and sheep, oats
                      (grain), peppers, pumpkins, safflower
                      seed, snap beans, sugar beets, tomatoes,
                      and wheat (grain)

                      peanuts                                      0.05

                      milk                                         0.01

    U.S.S.R.          all crops                                    1

                      fodder crops                                 2
                                                                             


    REQUIRED (before June 1978)

         1.   Long-term carcinogenicity study.

    DESIRABLE

         1.   Further studies on the spontaneous conversion of trichlorfon
              to dichlorvos in vitro and in vivo and of the possible
              intermediates involved.

    REFERENCES

    Bayer. (1972) Unpublished reports Bayer Leverkusen Nos. 44/72, 45/72,
    46/72, 47/12

    Bayer. (1965, 1968) Unpublished reports Bayer Leverkusen Nos. 256/65
    and 7/68

    Bayer. (1965) Unpublished reports Bayer Leverkusen, Nos. 25/65, 258/65

    Bayer. (1967) Unpublished report Bayer Leverkusen No. 69/67

    Bayer. (1968) Unpublished reports Bayer Leverkusen, Nos. 4/68, 5/68,
    and 6/68

    Bonashevskaya, T. I. and Tabakova, S. A. (1972) Morphological
    Alterations Occurring in Albino Rat Organs Following Inhalation of
    Chorofos. Farmakol Toksikol (Moscow), 35:240-241. (Reviewed in
    abstract only)

    Chemagro. Unpublished reports Chemagro Nos. 14940, 14945

    Chemagro. Unpublished reports Chemagro Nos. 14941, 14946, 14983

    Chemagro. (1956) Unpublished report No. 2696, Dept. of Ent. Univ. of
    Manitoba Canada (Chemagro report).

    Chemagro. (1972) Unpublished report Chemagro No. 21311 (Bayer reports
    155/72, 157/72)

    Chemagro (1962) Unpublished reports Chemagro Nos. 8555, 8560, 8562,
    8974

    Chemagro. (1972) Unpublished report Chemagro No. 21811 (Bayer reports
    156/72, 158/72)

    Chemagro. (1957, 1959) Unpublished report No. 2697, Agr. Exp. Sta.
    Mesa, Arizona (Chemagro report)

    Gibel, Von W., Lohs, Kh., Wildner, G. P., Ziebarth, D. and Streglitz,
    R. (1973) Uber die Kanzerogene hamatoxische und hepatotoxische Wirkung
    pestizider organischer phosphorverbindungen. Arch. Geschwultstforsch.,
    41:311-328

    Gibel, Von W., Lohs, Kh., Wildner, G. P. and Ziebarth, D. (1971)
    Tierexperimentelle untersuchungen uber die hepatotoxische und
    Kanzerogene wirkung phosphoroganischer verbindungen. Arch. fur
    Geschwulstforschung, 37:303-312

    Karmelov, V. A. (1973) Subacute Experimental Chlorphos Poisoning
    (Morphopathochemical Investigation). Farmakol. Toksikol (Moscow),
    36:727-728. (Reviewed in abstract only)

    Kimmerle, G. and Loser, E. (1974) Delayed Neurotoxicity of
    Organophosphorus Compounds and Copper Concentration in the Serum of
    Hens. Environ. Quality & Safety, 3:173-78

    Koivurinta, J. and Koivistoinen, P. (1975) Trichlorfon residues in
    lettuce; in press, Acta agric. Scand.

    KvW No. 71. Control of beet-fly on spinach; unpublished report No. 71,
    Food Inspection Service, Amsterdam 1962 (in Neth. language)

    KvW No. 105. (1965) Residues of diazinon, ronnel, trichlorfon, and
    mevinphos on spinach; unpublished report No. 105, Food Inspection
    Service, Amsterdam, 1965 (in Neth. language)

    KvW No. XXII. (1957) Residues of phosphoric esters on glasshouse
    spinach (in Netherl. language); unpublished report No. XXII, Food
    Inspection Service, Amsterdam, 1957

    Lange, H. and MacCalley, N. F. (1959) Report 4820, Univ. of California
    (Chemagro report)

    Lazarov, V. P. and Magat, A. (1975) Aspects biochimiques et
    physiopathologiques de l'intoxication aiguë et à moyen terme du poulet
    avec le trichloron. Bull. Soc. Sci et Méd. comparée (Lyon), 77, (2),
    89-97

    RIV 96/74. (1974) Residues of pesticides in vegetable crops grown
    under glass; report RIV 96/74, Tox/Rob. National Institute of public
    Health, Bilthoven, the Netherlands

    Rodionov, G. A. and Voronina, L. Ya. (1973) On the Effect of
    Trichlorfon on the Course of Pathology of the Liver in the Experiment.
    Vrach. Delo., 11:48-52. (Reviewed in abstract only)

    Yasnova, G. P., Alibasov, T. G. and Tsarogorodtseva, G. N. (1971) 
    Pathological and Histochemical Changes in Organs and Tissues of Calves
    Given Certain Organophosphorus Insecticides over a Long Period.
    Problemy Veterinarnoi Sanitarii, 39:228-233. (Reviewed in abstract
    only)
    


    See Also:
       Toxicological Abbreviations
       Trichlorfon (EHC 132, 1992)
       Trichlorfon (HSG 66, 1991)
       Trichlorfon (JECFA Food Additives Series 51)
       Trichlorfon (WHO Food Additives Series 45)
       TRICHLORFON (JECFA Evaluation)
       Trichlorfon (WHO Pesticide Residues Series 1)
       Trichlorfon (Pesticide residues in food: 1978 evaluations)
       Trichlorfon (IARC Summary & Evaluation, Volume 30, 1983)