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    CHLOROTHALONIL      JMPR 1977

    Explanation

    Chlorothalonil was reviewed by the 1974 Joint Meeting (FAO/WHO, 1975)
    and the following information was required by 1977.

    1. Additional studies to resolve lower limit for kidney effects in the
    rat.

    2. Determination of growth reduction in pups relative to dietary
    ingestion or secretion into maternal milk.

    3. Data on residues of chlorothalonil and the 4-hydroxy metabolite in
    crops that may be fed to animals.

    4. The results of feeding studies on dairy cattle, understood to be in
    progress, to determine the level and nature of residues in milk and
    tissues.

    In addition, the following information was considered to be desirable.

    1. Observation in humans.

    2. Residue data for food moving in commerce.

    3. Further information on the effects of processing, including
    household cooking, on residues.

    The Codex Committee on Pesticide Residues at its 9th session (Alinorm
    78/24, paras. 144, 145) also asked the Joint Meeting to present the
    residues levels and pre-harvest intervals in a more understandable
    manner so that countries would be in a better position to judge the
    data. Justification was requested for the suggested one day
    pre-harvest interval for such crops as sugar beets, carrots and
    potatoes.

    A considerable amount of information was submitted by the principal
    manufacturer concerning the specific requirements of the 1974 Joint
    Meeting, which is reviewed below.

    EVALUATION FOR ACCEPTABLE DAILY INTAKE

    BIOCHEMICAL ASPECTS

    Single cows were fed either 250 ppm technical chlorothalonil, 2 ppm
    pure 4-hydroxy metabolite of chlorothalonil, or normal diet for 44
    days. A 15-day recovery period with all animals on normal diet
    preceded sacrifice of the test animals. Milk production was reduced in
    the cow receiving the 4-hydroxy-metabolite. Food consumption was
    comparable in all animals. Neither test animal showed any gross
    pathological lesions at sacrifice (IBT). No residues of chlorothalonil
    were detected in either meat or milk. The 4-hydroxy metabolite

    occurred in the milk of both test animals, being present as 23% of the
    administered dose of the 4-hydroxy-metabolite, and as 0.2% of the
    administered chlorothalonil dose (Ladd et al., 1971; Wolfe & Stallard,
    1971). Further details are given in the section "Fate of Residues",
    "In animals".

    Degradation of chlorothalonil in cow bovine rumen fluid has been shown
    to result in 4-5% of the administered dose of chlorothalonil being
    converted to the 4-hydroxy metabolite in vitro (Duane, 1971).

    TOXICOLOGICAL STUDIES

    Special study on reproduction

    Five groups of 10 male and 20 female rats were fed 0, 10, 50, 100 or
    200 ppm 4-hydroxy-2,5,6-trichloroisophthalonitrile in a three
    generation, one litter/generation reproduction study. Increased
    irritability in adults in the Fo, F1 and F2 generations and rough
    thin coats in weanlings of the F1, F2 and F3 generations were noted
    at 200 ppm. Soft stools occurred occasionally at 100 and 200 ppm. Body
    weight of offspring in all generations showed a decreased weight gain
    at 50, 100 and 200 ppm, the decrease being marginal (10-15%) at 50
    ppm. In post-weaning animals, body weight gain was decreased in
    females of the Fo generation at 200 ppm. In other generations weight
    gain was similar to controls, but the initial losses during weaning
    were not recovered. Fertility index was reduced in the F2 parents at
    100 and 200 ppm and in F1, parents at 200 ppm. Gestation index was
    comparable in all groups. The viability index was normal for all
    groups up to 24 hrs, decreased at 200 ppm in F2 and F3  and at 50
    ppm in the F3 offspring over the 0-4 day period, decreased at 200 ppm
    in the F2 and F3 and at 50 & 100 ppm in the F3 offspring over the
    0-7 day period. After culling to 10/litter at 7 days, viability index
    over the 7-14 day period was reduced at 200 ppm in all generation, and
    at 100 ppm in the F3 generation. Total pup mortality was increased in
    all generations at 200 ppm, at 100 ppm in the F2 and F3 litters, and
    at 50 ppm in the F3 litters. A marginal increase also occurred at 10
    ppm in the F3 litters.Litter size was reduced at 200 ppm in all
    generations, and at 100 ppm in the F3 litters. Incidence of
    stillbirths was comparable in all groups. Examination of pups from
    F1, F2 & F3 generations either grossly or by alizarin staining did
    not reveal terata (Hastings, 1975). Histopathological examination of
    F3 weanlings (5 male and 5 female/group) did not reveal any
    abnormalities (Ferrell, 1975).

    Pups, culled at 7 days of age, were subject to analysis of stomach
    content. No solid matter was found in the stomach. Levels of
    4-hydroxy-2,5,6-trichloroisophthalonitrile increased with
    increasing-dose level (Ferrel, 1975).

    Short-term studies

    Rat

    Seven groups of 15 male and 15 female Young adult Wistar rats were fed
    1, 2, 4, 15, 30, 60 or 120 ppm chlorothalonil in the diet for 17
    weeks. A concurrent control group of 30 male and 30 female rats were
    fed normal laboratory chow.

    All rats were stated to present a healthy appearance throughout the
    study. Body weight, food consumption and survival were comparable in
    all groups. At termination of the study, all rats were sacrificed.
    Kidney, liver and thyroid from each animal were removed and grossly
    examined. Most kidneys had fat-like nodules on them and a number of
    livers were mottled and discoloured (Hastings & Jessop, 1975). Kidney
    histopathology did not reveal compound or dose-related changes (Busey,
    1975).

    COMMENTS

    The data previously required from additional studies to resolve the
    lowest dose limits for kidney effects in the rat and the determination
    of growth reduction in pups relative to dietary intake or secretion
    into maternal milk were submitted for consideration by the Meeting.
    The absence of sufficient detail in the reports on kidney pathology
    and discrepancies in body weight data in the rat reproduction studies
    made evaluation of these data impracticable. However, since data have
    been submitted in response to the previous request, the Committee
    extended the current temporary ADI for humans for an additional 2
    years.

    TOXICOLOGICAL EVALUATION

    Levels causing no toxicological effect

    Rat: 60 mg/kg in the diet, equivalent to 3.0 mg/kg bw
    Dog: 120 mg/kg in the diet, equivalent to 3.0 mg/kg bw

    ESTIMATE OF TEMPORARY ACCEPTABLE DAILY INTAKE FOR HUMANS

    0-0.03 mg/kg bw

    RESIDUES IN FOOD AND THEIR EVALUATION

    USE PATTERN

    As indicated by the 1974 Joint Meeting, chlorothalonil is a wide
    spectrum fungicide effective against many fungus diseases of fruits,
    vegetables, turf and ornamental crops. A very important use at present
    is in tropical areas such as Central and South America and Southeast
    Asia for protecting bananas from Sigatoka disease
    (Cercospora musae), fruit spot and pitting disease, among others.

    The compound is usually formulated as a 75% wettable powder and a 720
    g/l suspension concentrate. Additional specific data on use patterns
    were submitted by the Netherlands. (Table 1).

    RESIDUES RESULTING FROM SUPERVISED TRIALS

    The 1974 Joint Meeting made a comprehensive tabulation of the
    available data on residues resulting from supervised trials with
    chlorothalonil. Although the 9th session of the Codex Committee on
    Pesticide Residues expressed its concern that the data presented could
    not be readily understood, the absence of the original data sets does
    not allow the reviewer to make any changes in the tabulation to make
    it clearer. It also appears that the reservations expressed at the
    CCPR were due to a misunderstanding since they concerned pre-harvest
    intervals used in supervised trials, whereas the recommendations
    mention pre-harvest intervals which were used as the basis of the
    proposed maximum residue limits.

    Additional residue data were provided by the principal manufacturer
    for peaches and bananas. In both cases two types of extraction
    were used, namely simple surface rinsing and the more exhaustive
    total maceration. In the case of peaches the differences between
    the two procedures were not significant (Table 2), so surface rinsing 
    was used to gather residue data from several locations in the
    United States (Table 3). Occurence of the metabolite
    2,5,6-trichloro-4-hydroxy-1,3-benzenedicarbonitrile (DAC-3701)
    was low (Table 4).

    In bananas, there also appears to be no significant difference between
    the residue levels obtained by surface stripping and maceration (Table
    5). Analysis shows that the fungicide remains mainly in the peel and
    very little is translocated to the edible portion, as shown in Table
    6. Formation of DAC-3701 is also minimal.

    Residue data from the Netherlands on gherkins, leeks, potatoes and
    wheat are shown in Table 7.

    FATE OF RESIDUES

    General comments

    The only identified metabolite in the degradation of chlorothalonil is
    the 4-hydroxy compound, DAC-3701, mentioned previously.

    In animals

    To determine whether or not dairy cattle fed with a diet containing
    chlorothalonil and DAC-3701 will produce milk containing residues, a
    study was done in which one cow was fed with 250 mg/kg of 97%
    chlorothalonil and another with 2 ppm pure DAC-3701 for 44 days
    followed by a 15-day recovery period (Ladd at al., 1971; Wolfe and
    Stallard, 1971; referred to in the section "Biochemical aspects). Milk
    samples were collected during the test and recovery



        TABLE 1. Use pattern of chlorothalonil in the Netherlands
                                                                                                                                             

    Crop or situation   Kind of pest      Extent of use/        Application     Formulation       Treatment          Pre-harvest    In use
                        controlled        economic importance   kg. a.i./ha                                          interval       since
                                                                                                                     (days)
                                                                                                                                             
    potato              Phytophthora      small scale           1.5-2.2         w.P. 75T          repeated           -----          1966
                                                                                                  treatments

    mushroom            Verticillium       small scale           3 g/m2          w.p. 75%          first treatment    5 days         1977
                        sp.                                                                       after covering;
                                                                                                  repeat two
                                                                                                  weeks later
                                                                                                  after first
                                                                                                  harvest

    onion               Botrytis          small scale           2 kp/ha         W.P.              from 1             4 weeks        1976
                        squamosa                                                50% maneb         June., repeat
                                                                                25%               every 7-10 days
                                                                                chlorothalonil

    potato              Phytorphthora     moderate              0.75-1          idem              repeated           -----          1976
                                                                kg/ha                             treatments

    Wheat               powdery mildew    moderate              1.2kg/ha        w.p.              1 treatment,       6 weeks        1976
                       ripening diseases                                        40% sulfur        repeated
                                                                                20% maneb         once, if
                                                                                20%               necessary just
                                                                                chlorothalonil    before blossoming
                                                                                                                                             

    other uses: floriculture and against blue staining of wood

    W.P. = wettable powder


    TABLE 2. Chlorothalonil residues on peaches by surface and maceration extraction
                                                                                                                                   
                                     Application                       Preharvest
    Location     Type of       Formulation     Rate       Number      interval, days              Residues, mg/kg          Mean
                 extraction
                                                                                                                                   
    Louisiana    Surface       720 g/l         1.0 pt.      10            7                    2.51    3.55      10.08     5.65
                               suspension
                               concentrate
                 Macerate      "               1.0 pt.      10            7                    1.86    2.04      2.28      2.06
                 Surface       "               1.0 pt.      10            7                    1.76    2.32      1.88      1.99
                 Macerate      "               1.0 pt.      10            7                    1.14    0.92      1.60      1.22
                 Surface       "               1.5 pt.      10            7                    8.66    5.04      1.16      4.95
                 Macerate      "               1.5 pt.      10            7                    2.56    2.64      2.52      2.57

    Arkansas     Surface       "               1.5 pt.      5             15                   0.51    0.90      1.02      0.81
                 Macerate      "               1.5 pt.      5             15                   0.47    0.52      0.14      0.38
                 Surface       "               1.5 pt.      9             7                    4.50    2.66      0.75      2.64
                 Macerate      "               1.5 pt.      9             7                    0.24    0.60      1.73      0.86
                 Surface       "               1.5 pt.      9             0                    1.56    2.32      3.55      2.48
                 Macerate      "               1.5 pt.      9             0                    1.22    1.09      1.08      1.13

    Georgia      Surface       "               1.5 pt.      4             14                   0.71    1.13      1.50      1.11
                 Macerate      "               1.5 pt.      4             14                   0.80    0.91      0.84      0.85
                 Surface       "               1.5 pt.      4             4                    1.92    1.16      2.05      1.71
                 Macerate      "               1.5 pt.      4             4                    1.60    1.44      1.52      1.52
                 Surface       "               1.5 pt.      4             1                    2.86    2.37      1.80      2.59
                 Macerate      "               1.5 pt.      4             1                    1.83    1.80      1.80      1.81
                                                                                                                                   


    TABLE 3. Residues of chlorothalonil on peaches 1/
                                                                                                    
             Application                                                       Residue, mg/kg
    Rate per 100   % a.i.      Number       Preharvest        Samples        Range       Mean
    gals.2/                                 interval          analyzed
                                                                                                    
    0              0           -               0                42          ND - 0.20      0.03

    0.75           0.015       4               8                3           6.0 - 8.0      6.7

    1.0            0.02        4               0                4           6.15 - 15.8    11.49
                               4-10            7-8              18          0.92 - 10.08   3.42
                               4               12               33          1.04 - 3.08    1.78

    1.25           0.025       7               0                3           7.4 - 19.2     15.0
                               7               7                3           12.9 - 17.5    14.8
                               7               14               3           6.4 - 9.8      7.6

    1.50           0.03        8-10            0                11          1.08 - 16.2    6.77
                               4               1-4              12          1.16 - 2.86    1.91
                               4-11            6-8              27          0.24 - 22.2    5.29
                               4-6             12-15            27          0.14 - 6.4     2.14

    1.75           0.035       6-7             0                12          14.1 - 45.0    29.6
                               6               4                18          4.4 - 29.5     14.8
                               6-7             7                12          15.5 - 25.8    21.3
                               6-7             14               12          4.9 - 16.6     10.1
                               6               25               9           1.3 - 6.6      4.1

    2.0            0.04        4               8                3           26.6 - 28.4    27.8


    3.0            0.05        8               0                3           41.3 - 50.5    44.8
                               4               8                3           32.4 - 54.0    45.1
                                                                                                    

    1/ Refers to both surface and macerated extraction data.
    2/ Both using the 75%. w.p. and 720 g/l s.c. formulations.

    TABLE 4. Formation of DAC-3701 on peaches treated with chlorothalonil.

                                                                                            

          Application 1/                                           Residues, mg/kg

    % a.i.            Number    Preharvest      Number        Range                Mean
                                interval        analyzed
                                                                                            
                      -            0             21           0.00 - 0.09            0.01

    0.015             3            0             3            0.12 - 0.31          0.18

                      3            10            3            0.13 - 0.21          0.18

    0.02              3            0             3            0.14 - 0.31          0.30

                      2-10         4             11           0.01 - 0.37          0.13

                      10           7             6            0.01 - 0.02          0.02

                      3-4          10-12         8            0.01 - 0.42          0.14

    0.025             3-9          0             6            0.00 - 0.48          0.17

                      4            1-4           6            0.00                 0.00

                      9-10         7             6            0.00 - 0.01          0.00

                      3-4          10-12         11           0.01 - 0.22          0.06
                                                                                            

    1/ Applied either as the W-75 or 6F

    


        TABLE 5. Mean residues of chlorothalonil in whole
    bananas using two extraction procedures.

                                                                             

                        Surface Striping              Maceration

    Treatment           Chlorothalonil          Chlorothalonil  DAC-3701
    (g a.i./1H2O)
                                                                             
    0.75                0.03                    0.02            ND

    1.5                 0.52                    0.30            ND

    3.0                 1.49                    1.32            ND

    Control             -                       0.04            ND
                                                                             
    
    
    TABLE 6. Distribution of chlorothalonil residues in bananas.

                                                                                      

    Treatment          Chlorothalonil    DAC-3701     Chlorothalonil     DAC-3701
    (g a.i./1H2O)
                                                                                      
    0.75               0.02              ND           0.09               ND

    2.0                0.02              ND           0.22               ND

    4.0                0.03              ND           3.80               0.01

    Control            0.05              ND           --                 0.01
                                                                                      

    

        TABLE 7. Residues of chlorothalonil in various crops (supervised trials, Netherlands).

                                                                                                                                         

                                  Application                   Residues (mg/kg) at intervals (days) after application

    Crop           Year    No.    Rate          Formulation      0/           3            7           14       41          41        41
                                  kg a.i./ha
                                                                                                                                         

    Potato         1971    6/7    2.2           75% WP                                   <0.02
                                                                                         (washed,
                                                                                         unpeeled
                                                                                         potatoes)

    Leek           1971    11     1.5           75% WP                                   13          7.7
                                                                                         (11-16)     (4.8-9.9)

    Gherkin        1973    1      2.2           75% WP           unwashed   unwashed
    (glasshouse)                                                 4.1        0.83
                                                                 (2.9-5.4)  (0.64-1.13)

                                                                 washed     washed
                                                                 1.2        0.30
                                                                 (0.9-1.7)  (0.24-0.37)

    Wheat          1974    2      1.2           75% WP                                                          whole
                                  kg/ha in                                                                      ear
                                  combination                                                                   0.52
                                  with 2.4 kg                                                                   (0.36-0.94)
                                  sulphur and
                                  1.2 mg maneb

                   1974    2      "             75% WP                                                          0.46
                                                                                                                (0.27-0.93) Whole     bran
                                                                                                                            grain

                   1976    1      "             75% WP                                                          0.37-0.78   0.04-0.06 1.5-3.4
                                                                                                                                           



    TABLE 8. DAC-3701 residues in milk of cows fed chlorothalonil or DAC-3701.

                                                                                                      

                                                           DAC-3701, mg/kg, in milk of
    Test Period                   Control               Chlorothalnil-fed      DAC-3701 fed
                                                        Cow                    Cow
                                                        (250 PPM in diet)      (2.0 ppm in diet)
                                                                                                      
    Pre-test                      0.05                  0.05                   0.05
    2                             0.05                  0.10                   0.19
    4                             0.04                  0.27                   0.19
    8                             0.04                  1.30                   0.75
    16                            0.04                  0.62                   0.66
    18                            0.09                  0.84                   0.94
    20                            0.01                  0.96                   1.54
    22                            0.01                  0.92                   0.96
    26                            0.10                  1.19                   1.27
    30                            0.13                  0.94                   1.12
    32                            0.02                  0.97                   0.90
    34                            0.01                  0.83                   1.26
    38                            0.01                  1.00                   0.95
    44                            0.01                  0.59                   1.16

    Recovery Period

    1                             0.01                  0.60                   1.30
    3                             0.01                  0.42                   1.10
    6                             0.04                  0.37                   0.90
    10                            0.06                  0.23                   0.56
    15                            0.04                  0.19                   0.32
                                                                                                      

    

    period. The animals were then milked and samples of liver, kidney,
    muscle and fat were analyzed.

    No chlorothalonil was detected in the milk of the cow fed with
    chlorothalonil but DAC-3701 was detected in the milk of both cows
    (Table 8). Only 0.2% of the ingested chlorothalonil was eliminated in
    the milk as DAC-3701. Residues of the metabolite became constant after
    about 18 days of treatment but declined rapidly during the recovery
    period. In the tissues, no residues of either compound could be
    detected in the muscle or fat but 0.7 and 1.2 mg/kg of DAC-3701 were
    detected in the kidneys of the chlorothalonil- and DAC-3701- fed cows,
    respectively. Traces (0.1 mg/kg) of DAC-3701 were found in the liver
    of the cow fed with DAC-3701.

    In silage

    The effect of ensiling treated foliage is important in view of its
    probable effect on the residue levels in milk or meat of animals
    consuming the silage as feed. This is particularly important with
    chlorothalonil since residues are expected to remain in the treated
    plant material prior to ensiling. On the other hand, chlorothalonil is
    biodegradable and this could minimize residue levels. This latter
    observation was borne out by ensiling studies which showed that with
    corn silage, 90% degradation was observed after 18 days (from 30 mg/kg
    to 3 mg/kg) and the half-life was approximately 4 days. No formation
    of DAC-3701 was observed. In a second experiment in which the bound
    materials in the silage were converted to an extractable form,
    DAC-3701 constituted only 2% of the chlorothalonil in the silage on
    the first day of ensiling.

    During processing

    The 1974 Joint Meeting reported the effect of washing with water on
    chlorothalonil residues. For the present Meeting, the principal
    manufacturer submitted the results of studies of the effect on
    residues of processing tomatoes and peaches. For tomatoes, it was
    shown that 94% of the chlorothalonil residues were removed by washing
    fresh tomatoes and that no detectable chlorothalonil or DAC-3701 was
    found in the products canned tomato pulp, tomato paste or tomato
    juice. The dry cannery waste (tomato pomace), which is sometimes used
    for feed, contained less than 1 mg/kg of total residues at roughly a
    6:1 chlorothalonil:DAC-3701 ratio.

    Washing peaches with water followed by a caustic wash removed 97% of
    the field residues remaining on the peaches. The caustic wash will
    increase chlorothalonil removal because chlorothalonil is unstable at
    pH 10 and above. No chlorothalonil or DAC-3701 could be detected in
    canned peach puree.

    RESIDUES IN FOOD MOVING IN COMMERCE

    No data were made available but the principal manufacturer mentioned
    that this could be supplied by the United States Food and Drug
    Administration, presumably through the Chairman of the U.S. Delegation
    to the Codex Committee on Pesticide Residues.

    APPRAISAL

    The compound was re-evaluated in the light of information requested by
    the 1974 Joint Meeting and the decision of the 1977 Codex Committee on
    Pesticide Residues to change the temporary maximum residue limit in
    oranges to encompass all citrus fruits. The 1974 Meeting recommended a
    maximum residue limit of 30 mg/kg in peaches, but the principal
    manufacturer suggested that this could be reduced to 25 mg/kg.
    Supporting data, mainly from the United States, justifies such a
    reduction. In bananas, the fungicide remains mainly in the peel.

    When dairy cows were fed diets containing very high levels of
    chlorothalonil or 2,5,6-trichloro-4-hydroxy-1,3-benzocarbonitrile
    (DAC-3701), approximately 0.2% of the chlorothalonil and 23% of the
    DAC-3701 were eliminated in the milk as DAC-3701. Of the tissues
    examined, only the kidneys contained residues above the limit of
    determination.

    After being ensiled for 18 days, maize forage was found to contain 10%
    of the initial residues.

    Washing removed up to 94% of the chlorothalonil residues in tomatoes
    and up to 97% in peaches and residues could not be detected (< 0.01
    mg/kg) in tomato and peach processing products.

    RECOMMENDATIONS

    The temporary maximum residue limits recommended in 1974 are
    maintained as temporary limits with the exception of that for peaches
    which is lowered and for "oranges" which is changed to "citrus fruit".
    An additional temporary limit is recommended for bananas.

                   Commodity           Limit, mg/kg

                   Peaches             25

                   Citrus fruit        5

                   Banana (whole)      4

                   Banana (pulp)       0.1

    FURTHER WORK OR INFORMATION

    Required (before July 1979)

    1. Additional studies to resolve the lower dose limits for kidney
    effects in rats.

    2. Studies to define the growth reduction after administration of
    chlorothalonil or its metabolite 4-hydroxy-2,5,6-trichloroisothalonile
    in pups relative to ingestion or secretion into milk.

    Desirable

    1. Observations in humans.

    2. Information on the extent of metabolism to
    4-hydroxy-2,5,6-trichloroisothalonile in mammals.

    3. Information on the effects of cooking on residues.

    REFERENCES

    Busey, W.M. (1975) Project 24-201. Unpublished Report by Experimental
    Pathology Laboratories Inc. submitted to WHO by Diamond Shamrock Corp.

    Duane, W.C. (1971) Reinvestigation of the degradation of
    Chlorothalonil by Bovine Rumen Fluid. Unpublished Report submitted to
    WHO by Diamond Shamrock Corp.

    Ferrell, J.F. (1975) Pathology Report on F3 Rats. Unpublished Report
    by Experimental Pathology Laboratories Inc. submitted to WHO by
    Diamond Shamrock Corp.

    Hastings, T.F. (1975) Three generation Reproduction Study in Albino
    Rats DAC-3701. Unpublished Report by Bio/Tox Research Laboratories
    Inc., submitted to WHO by Diamond Shamrock Corp.

    Hastings, T.J. and Jessop, D.C. (1975) 4-Month Dietary Toxicity Study
    - Rats. Chlorothalonil. Final Report. Unpublished Report by Bio/Tox
    Research Laboratories Inc. submitted to WHO by Diamond Shamrock Corp.

    Ladd, K., Jenkins, D.H. and Kepplinger, M.L. (1971) Meat and Milk
    Residue Study with Technical Daconil 2787 - 97% and pure DAC-3701 in
    Dairy Cattle. Unpublished Report by Indistrial Biotest Laboratories,
    submitted to WHO by Diamond Shamrock Corp.

    Wolfe, A.L. and Stallard, D.E. (1971) Supplementary Milk and Meat
    Study. Unpublished Report submitted to WHO by Diamond Shamrock Corp.

    FAO/WHO (1975) 1974 evaluations of some pesticide residues in food.
    AGP:1974/M/11; WHO Pesticide Residues Series, No. 4.
    


    See Also:
       Toxicological Abbreviations
       Chlorothalonil (EHC 183, 1996)
       Chlorothalonil (HSG 98, 1995)
       Chlorothalonil (ICSC)
       Chlorothalonil (WHO Pesticide Residues Series 4)
       Chlorothalonil (Pesticide residues in food: 1981 evaluations)
       Chlorothalonil (Pesticide residues in food: 1983 evaluations)
       Chlorothalonil (Pesticide residues in food: 1985 evaluations Part II Toxicology)
       Chlorothalonil (Pesticide residues in food: 1987 evaluations Part II Toxicology)
       Chlorothalonil (Pesticide residues in food: 1990 evaluations Toxicology)
       Chlorothalonil (Pesticide residues in food: 1992 evaluations Part II Toxicology)
       Chlorothalonil  (IARC Summary & Evaluation, Volume 30, 1983)
       Chlorothalonil  (IARC Summary & Evaluation, Volume 73, 1999)