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    FAO/PL:1968/M/9/1

    WHO/FOOD ADD./69.35

    1968 EVALUATIONS OF SOME PESTICIDE RESIDUES IN FOOD

    THE MONOGRAPHS

    Issued jointly by FAO and WHO

    The content of this document is the result of the deliberations of the
    Joint Meeting of the FAO Working Party of Experts and the WHO Expert
    Committee on Pesticide Residues, which met in Geneva, 9-16 December,
    1968.

    FOOD AND AGRICULTURE ORGANIZATION OF THE UNITED NATIONS

    WORLD HEALTH ORGANIZATION

    Geneva, 1969

    CHLOROBENZILATE

    This pesticide was evaluated for acceptable daily intake by the 1965
    Joint Meeting of the FAO Committee on Pesticides in Agriculture and
    the WHO Expert Committee on Pesticide Residues (FAO/WHO, 1965). Since
    the previous evaluation, additional data has become available and the
    monograph has been greatly expanded and is reproduced in its entirety.

    IDENTITY

    Biological activity

         acaricide

    Chemical names

         ethyl 4,4'-dichlorobenzilate

         ethyl 2-hydroxy-2,2-di(p-chlorophenyl)-acetate. (IUPAC)

    Synonyms

         Acaraben(R), Akar(R), Gesaspint(R)

    Structural formula

    CHEMICAL STRUCTURE 

    Other information on identity and properties

    The technical material consists of a yellow-brown oily liquid with a
    purity of at least 90 per cent. No data have been submitted on the
    composition of the technical product.

    EVALUATION FOR ACCEPTABLE DAILY INTAKE

    Biochemical aspects

    Three groups, each containing one male and one female dog, were given
    0, 12.8, or 64.1 mg/kg/day for five consecutive days. At autopsy, five
    days after the termination of treatment, no residues could be detected

    in whole blood, liver, kidney, muscle, fat, or brain tissues. At 12.8
    mg/kg/day, the male excreted 31 per cent of the total dose in the
    urine within 10 days. Urinary excretion in the female accounted for 41
    per cent. Faecal levels contained 5.6 per cent and 6.6 per cent for
    the male and female respectively. At 64.1 mg/kg/day urinary and faecal
    elimination was 31 per cent and 1.7 per cent respectively for the
    male, and 23 per cent and 26 per cent for the female. The method of
    analysis would not detect conjugates of 4,4'-dichlorobenzilic acid
    which is suggested to be the major metabolite (Hazleton Laboratories
    Inc., 1964). Dichlorobenzilic acid has been qualitatively identified
    in dog urine by thin-layer chromatographic techniques (Mattson et al.,
    1965).

    Acute toxicity (oral)

                                                                               
    Animal     Route     Compound or      LD50 (mg/kg    Reference
                           solvent        body-weight)
                                                                           

    Mouse      Oral      Suspension in       4 850       Gasser, 1952
                         gum arabic

    Mouse      Oral      Technical             729       Horn et al., 1955
                         material

    Rat        Oral      Suspension in       3 100       Gasser, 1952
                         gum arabic

    Rat        Oral      Technical             702       Horn et al., 1955
                         material

    Rat        Oral      25 per cent.          735       Horn et al., 1955
                         xylene
                         emulsion
                                                                           
    
    Short-term studies

    Avian wildlife

    Groups of 10 Mallard ducks (Aras platyrhynchus) were fed 0, 0.25,
    0.45 and 0.8 per cent of chlorobenzilate for five consecutive days.
    The LD50 was greater than 0.8 per cent. Body-weight gain and food
    intake was slightly reduced in all test groups (Woodard, 1965a).

    Groups of 10 quail (Colinus virginianus) were fed 0, 0.14, 0.25
    and 0.5 per cent of chlorobenzilate in their diet for seven days. The
    LD50 was 0.34 per cent. Bodyweight, food intake and gross pathology
    of the survivors appeared unaffected (Woodard, 1965a).

    Rat

    Groups, each of 20 male rats, were fed 0, 40 and 800 ppm technical
    chlorobenzilate in their diet for 48, 48 and 44 weeks, respectively.
    Mortality was slightly higher in the 800 ppm group than in the control
    group. The growth of the animals fed 800 ppm was retarded, and several
    animals exhibited red or swollen eyelids and soft faeces. Organ to
    body-weight ratios for the 40 ppm group were significantly greater
    than for the controls, in the case of liver, kidney and testes.
    Similar data for the 800 ppm group were not evaluated statistically,
    but organ to body-weight ratios in the case of the liver and kidney
    appear to be greater than for the controls. Gross pathological
    examination revealed no changes attributable to compound
    administration, but upon histological examination non-specific changes
    were observed in the pancreas and adrenals of animals in both test
    groups, and increased hemopoietic activity in the spleens of the 800
    ppm groups. Tissue analysis indicated that chlorobenzilate was not
    stored in the animal to any appreciable extent (Hazleton Laboratories,
    1953a).

    Groups of five male rats received 0, 1, 3 or 5 per cent technical
    chlorobenzilate in the diet, and groups of five female rats received
    0, or 3 per cent, in the diet. All animals receiving chlorobenzilate
    at these levels died, those receiving one per cent within 59 days,
    three per cent within eight days, and five per cent within six days.
    Reduced food consumption, and marked loss of body-weight preceded
    death.(Hazleton Laboratories, 1953b).

    A 15 week feeding study, utilizing groups of five male rats at dose
    levels of 0, 500, 1000, or 5000 ppm technical chlorobenzilate resulted
    in reduced food consumption, and growth retardation in all test
    groups. Mortality was 40 per cent at 1000 ppm, and 100 per cent at
    5000 ppm (Hazleton Laboratories, 1953b).

    In a 17 week feeding study using groups of 20 male rats fed 0, 50, and
    500 ppm, and 20 female rats at 0, and 500 ppm, body weight gain was
    depressed in the male only, at 500 ppm. Food intake was not
    significantly depressed (Hazleton Laboratories, 1953b).

    Groups of 20 male and 20 female rats treated for 99 days, with a 20
    per cent chlorobenzilate powder mixed in their diet at dose levels of
    0, 20, 100, 500, and 2500 ppm active ingredient did not show any toxic
    effects as judged by food consumption, body-weight, mortality, organ
    weights, gross, or histopathology except at the top dose level. At
    2500 ppm active ingredient, food intake was reduced initially,
    body-weight gain was reduced, absolute testes and spleen weights were
    below control levels (insufficient data available to calculate organ
    to body-weight ratios), and histopathological examination revealed
    three rats with increased fatty deposits in the liver lobules, as well
    as five rats with spermatogenentic injury, and testicular atrophy
    (Domenjoz, 1965a).

    Dog

    Pairs of dogs (one male and one female) were fed 12.8, or 64.1 mg/kg
    five times weekly for 35 weeks, except for two periods of five days
    when excretion studies were performed. No toxic effects were apparent,
    judging by growth, general appearance, hematology, urinalysis, liver
    function test, and gross and microscopic pathology. The excretion
    studies showed that the majority of administered material was excreted
    in the urine, the metabolite having a 4,4'-dichlorodiphenyl methyl
    structure. No chlorobenzilate was present in the urine three days
    after withdrawal (Horn et al., 1955).

    In a two year feeding study utilizing the 25 per cent powder
    formulation, groups of three male and three female dogs were fed 0,
    100, or 500 ppm active ingredient in the diet. A further group of
    three male and three female dogs were fed 5000 ppm active ingredient
    for 14 weeks. One male and one female were maintained at this dose
    level for 20 weeks when they were sacrificed. The remainder, after a
    five week withdrawal period, were replaced in the study by a 3000 ppm
    dose level, until the completion of the test. At 100, and 500 ppm, the
    parameters considered were comparable to the control group. At 3000
    ppm, body-weight depression, mild anaemia and increased liver and
    spleen to body-weight ratios were observed in both sexes. At 5000 ppm,
    in addition to these effects, food intake was depressed, anaemia was
    moderately severe, serum alkaline phosphatase values were elevated,
    and the albumen to globulin ratio was reversed. The histopathology,
    presumably performed at 104 weeks, indicates no compound related
    effects at 100 and 500 ppm. At the top level, extramedullary
    haematopoiesis was evident in liver and spleen as well as erythroid
    hyperplasia of the bone marrow (Hazleton Laboratories Inc., 1965).

    Sheep and beef-cattle

    Sheep were exposed to chlorobenzilate 25 per cent wettable powder in
    the diet for four weeks at dose levels of 0 (two females), 3.6 (two
    females), 8.7 (two females) or 29 (one male and four females) ppm
    active ingredient, and beef-cattle at dose levels of 0 (one male and
    one female), 3.2 (one male and one female), 8.8 (one male and one
    female), or 27 (one male and one female) ppm active ingredient. The
    sheep and cattle failed to show compound related toxic symptoms as
    judged by food consumption, bowel evacuations, physical condition and
    behaviour, haematology, or gross necropsy observation. One cow dosed
    at 3.2 ppm aborted a six-month foetus on day four. However, a second
    cow dosed at 8.8 ppm carried a fully-developed foetus until sacrificed
    (Woodard, 1965c).

    Long-term studies

    Rat

    A two year study, using technical chlorobenzilate at 0 (20 male and 20
    female), 50 (20 male) and 500 ppm (20 male and 20 female) showed

    decreased body-weight gain, as well as unthriftiness, and blood tinged
    crusts about the nose and eyes at 500 ppm. An increased incidence of
    testicular atrophy was noted at both 50 and 500 ppm without
    histological change (Horn et al., 1955).

    A second two year study utilizing groups of 30 male and 30 female rats
    at dose levels of 0, 40, 125 and 400 ppm active ingredient as the 25
    per cent wettable formulation showed no significant changes in
    body-weight gain, or food intake. Haematologic values did not show any
    consistent changes related to dose level, or length of exposure to the
    test material. Incidence of neoplasms was unrelated to the
    administration of the test substances. Adverse effects on organ to
    body-weight ratios were noted in the case of liver at 400 ppm. In the
    histopathological examination of tissues, changes were observed in
    liver, kidney and testes at 400 ppm, and in kidney and testes at 125
    ppm. Gross autopsy observations indicated testicular changes at 125
    and 400 ppm (Woodard, 1966).

    Special studies

    (a)  Reproduction

    A three generation study, utilizing 20 male and 20 female rats at 0,
    and 50 ppm active ingredients as the 25 per cent wettable formulation
    in the first generation, and, 10 male and 20 female rats at 0, 25 and
    50 ppm active ingredient in the second and third generations failed to
    reveal any toxic effects on adult body-weight, resorption rates, or
    histology (performed on F1b adults). Absolute testes weights for the
    F1b adults (the only group reported) showed a significant decrease at
    50 ppm active ingredient. The litters all appeared normal as judged by
    litter size, birth weight, stillbirths, survival to weaning, weanling
    weights, and F3b weanling histopathology. Adult fertility, as judged
    by number of litters per group appeared normal, but chlorobenzilate
    withdrawal at weaning for 15 days, and at weaning for 28 days in F1b
    and F2b weanlings, respectively, leaves this parameter open to
    question. No teratogenic changes were observed at any stage in the
    study (Woodard, 1965b).

    (b) Studies on the metabolite

    The metabolite, dichlorbenzilic acid was fed to groups of 20 male and
    20 female rats for 99 days at dose levels of 0, 20, 100, 500 and 2500
    ppm active ingredient in a 20 per cent powder. Food consumption
    body-weight gain, mortality, organ weights, and gross and
    histopathology showed no significant changes from the controls, except
    possibly for a slight depression of kidney and testes weight at 2500
    ppm (Domenjoz, 1965b).

    Comments

    Adequate data have been presented on short-term and long-term studies
    in rats and dogs. Biochemical data on excretion, and a tentative
    identification of the major metabolite are also available. All the

    studies appear to be reliable and sufficiently adequate to permit
    evaluation. The slight doubts regarding the incidence of neoplasms
    observed in the long-term study on the rat makes it desirable to
    obtain information from a second species.

    TOXOCOLOGICAL EVALUATION

    Level causing no significant toxicological effect

         Rat: 40 ppm in the diet, equivalent to 2 mg/kg body-weight

         Dog: 500 ppm in the dry diet, equivalent to 12.5 mg/kg 
              body-weight

    Estimate of acceptable daily intake for man

         0-0.02 mg/kg body-weight

    RESIDUES IN FOOD AND THEIR EVALUATION

    Use pattern

    Pre-harvest treatments

    Chlorobenzilate is used as a contact acaricide for the control of
    adult spider mites; it is also effective against summer eggs and all
    post-embryonic stages. The compound is used in many countries
    throughout the world for the control of several mite species on
    apples, pears, stone fruits, citrus fruits, soft fruit, grapes,
    olives, vegetables, coffee, tea, cotton and ornamentals.
    Chlorobenzilate is less effective at lower temperatures, and in
    countries with a temperate climate, it is primarily used on
    glass-house crops and only to a small extent outdoors. In view of its
    specific acaricidal activity and its non-toxicity to bees, it may be
    usefully applied in integrated control schemes. In certain instances
    it is being recommended when resistance to other acaricides has
    developed.

    The recommended rates of application range from 25-50 g/100 l, and the
    mount of spray liquid applied is generally 500-1000 l/ha for low-grown
    crops (vegetables, etc) and 2000-2500 l/ha for high-grown crops (e.g.
    fruit orchards). (U.S. Dept. of Agric., 1967)

    Post-harvest treatments

    No post-harvest treatment is recommended.

    Other uses

    Chlorobenzilate is being used for the control of mites on ornamental
    plants. The compound is also used as a smoke for the treatment of
    bee-hives against tracheal mites (Gubler, 1953).

    Residues resulting from supervised trials

    Residue data are available from supervised trials on several food
    crops, grown under various conditions, using various rates of
    application and pre-harvest intervals (Geigy, 1968). These data refer
    to apples, citrus, nuts and vegetables (melons, cantaloupes). In most
    cases normal dosage rates were applied in accordance with label
    recommendations; in a few experiments higher dosages were included.
    Results mainly refer to work in the United States of America. Only
    limited data are available from other countries.

    The following table summarizes typical residue data.

                                                                                 
                   Rate of                     Post treatment    Residue, ***
    Crop           application    Number of    interval          whole fruit
                   (g/100 1)      treatments   (days)            basis (ppm)
                                                                             
    Apples             31             1               1              2.24
                       31             1               8              1.79
                       62             1               1              4.98
                       62             1               8              4.33
                       25             1               6              0.72
                       25             1              35              0.41
                       60             1              39              0.90

    Grapefruit         30             1               1              1.10*
                       30             1              22              2.04*

    Oranges            30             1               1              1.22*
                       30             1              22              1.99*

    Grapes             60             1              17              0.62*
                       60             1              34              1.06*
                      120             1              17              1.20*
                      120             1              34              1.15*

    Almonds            45            1-2            0-63           < 0.1

    Melons              0.56**        1               1            < 0.04-0.4
                        0.56**        1              14            < 0.04-0.13
                        2.24**        1               1              0.08-1.1
                        2.24**        1              14              0.09-0.39
                                                                             
    *   Based on peel; analysis of pulp showed residues of less than 0.1 ppm
        in the case of apples - no data on residues in pulp of grapes.
    **  kg/ha
    *** UV method (Blinn and Gunther, 1963) except GLC (see below) for grapes,
        almonds and melons.
    
    Fate of residues

    General comments

    Chorobenzilate can be considered as a persistent compound. More
    information is needed on the nature of terminal residues in plants,
    animals and their products.

    In soils

    No information available.

    In plants

    Experiments have been carried out to examine if and to what extent
    breakdown products derived from chlorobenzilate could be found, with
    particular reference to the possible occurrence of
    4,4'-dichlorobenzilic acid after apples were sprayed with 2 lbs/ 100
    gal and samples were taken 3, 14 and 21 days. The sensitivity of the
    analytical method was 0.1 ppm. In recovery studies,
    4,4'-dichlorobenzilic acid could be detected without interference of
    chlorobenzilate. It appears that chlorobenzilate is found mainly on
    the outer surface of the treated apples. No unchanged chlorobenzilate
    could be detected in the pulp of the apples. None of the treated
    apples contained detectable amounts of 4,4'-dichlorobenzilic acid
    (Murphy et al., 1966).

    In animals

    In experiments on sheep and cattle (Mattson and Schneller, 1966) 16
    per cent protein mixed grain containing chlorobenzilate was given in
    addition to a daily ration of mixed timothy and clover hay to eight
    sheep and six cattle (both sexes) over a period of four weeks. The
    dosage levels were 10, 24 and 80 mg chlorobenzilate per animal per day
    for sheep and 40, 110 and 340 mg chlorobenzilate per animal for
    cattle.

    Residues of unchanged chlorobenzilate were only found in cattle at the
    highest feeding level (340 mg/animal/day).

                                                                       
                             Residues in cattle
                                (ppm in fat)

                                            Males        Females
                                                                       
         subcutaneous fat                   0.54           0.32

         omental fat                        0.98           0.69

         perirenal fat                      0.54           0.69
                                                                       

    In another experiment (Woodard, 1960) chlorobenzilate was administered
    to six dairy cows at dietary levels of 20, 48 and 160 ppm in the feed
    (intake 4 lbs of treated feed per day) for a period of 15 days. After
    16 days, treatment with chlorobenzilate was terminated and the animals
    were given the same type of feed, without chlorobenzilate, to permit
    post-treatment analysis of milk samples. Milk samples were taken on
    the second, fourth, sixth, ninth and fifteenth days of the experiment,
    and again on the twentieth, twenty-first and twenty-second day.
    Chlorobenzilate in the milk was found in one "high-level" cow (160
    ppm) on the second day (0.15 ppm) and in one "medium-level" cow (48
    ppm) on the fourth day (0.15 ppm). On the fifteenth day, residues did
    not exceed 0.06 ppm. Since these levels are approaching the limit of
    sensitivity of the analytical method used, there is no distinct
    correlation between residue and feeding levels, and a number of
    negative values were obtained, the few positive values may be
    fortuitous. No 4,4'-dichlorobenzilic acid was found in the milk.
    Limited recovery studies show that this compound, if present, would be
    detected with the methods used.

    In the above short-term feeding experiments rather high dosages have
    been used, and more information is required on the possible occurrence
    of residues in milk after feeding normal dosage levels for a prolonged
    period.

    In storage and processing

    No data are available on the fate of residues during storage and
    processing. Since the residue remains mainly on the outer side of
    fruit and migrates only to a very small extent or not at all into the
    pulp, it may be expected that washing and peeling of treated fruit
    will remove most of the residue. No data are available on the effect
    of cooking.

    Evidence of residues in food in commerce or at consumption

    Food moving in commerce

    No information available.

    Food at the time of consumption

    In "market basket" or "total diet" studies (Cummings, 1966), carried
    out by the United States Food and Drug Administration, multidetection
    methods were used for residue analysis. The analytical procedure used
    for all samples in this study enabled the detection of about 54
    pesticide chemicals, including chlorobenzilate. So far no residues of
    chlorobenzilate have been found.

    Methods of residue analysis

    Several methods are available for residue analysis of chlorobenzilate,
    e.g. ultra-violet or infra-red spectrophotometry and gas-liquid
    chromotography. In former years the ultra-violet method, as described

    by Blinn and Gunther (1963) was used for determination of
    chlorobenzilate residues on apples, pears and citrus fruit. In
    addition Harris (1955) developed a modified Schechter-Haller infra-red
    spectrophotometric method for residue analysis of chlorobenzilate.
    This method was suitable for residue analysis on apples, pears and
    strawberries. A modification of this method is described by Margot and
    Stammbach (1964).

    At present a gas chromatographic method appears to be most suitable
    for use as a referee method, and should be developed for this purpose
    through collaborative studies, in particular, the comparative
    evaluation of the different detectors.

    The following is a brief description of the gas chromatographic
    determination of chlorobenzilate and chloropropylate in fruits,
    vegetables and nuts. The method is sensitive to 0.05 ppm:

    Chlorobenzilate and chloropropylate are extracted from the chopped
    material with petroleum ether (boiling range 30-60°C). Part of the
    extract is evaporated to dryness, taken up in benzene and transferred
    to an alumina column (basic, activity grade V). Interfering materials
    are removed by eluting with hexane or with 10 per cent benzene in
    hexane. Chlorobenzilate and chloropropylate are eluted with
    hexane/benzene (1:1) and the content is determined by gas
    chromotography using a glass column (4 ft × 0.25 in) packed with five
    per cent silicone gum GE XE - 60 (nitrile) supported on Anakrom ABS
    (50-60 mesh) with nitrogen as the carrier gas and a microcoulometric
    detector. Conditions: oven temperature, 215-220°C; block temperature,
    220-225°C; furnace temperature, 810-820°C; nitrogen flow, 80 ml/min;
    oxygen flow, 100 ml/min; pure nitrogen flow, 110 ml/min.

    Conditioning of the column is important and can be achieved by three
    to four injections of 30 micrograms of the acaricide. Retention times
    are approximately 4 min. Separation of chlorobenzilate and
    chloropropylate can be obtained by using a column loading of 10 per
    cent XE-60 and a column length of 6 ft (retention times approximately
    18 min for chlorobenzilate and 20 min for chloropropylate).

    Apples, pears, stone fruits, citrus fruits, berries, nuts, vegetables
    and cotton have been analysed for chlorobenzilate.

    Apples, pears, stone fruits, citrus fruits, almonds, cucumbers and
    beans have been analysed for chloropropylate.

    Typical recovery data with fortified samples (sample weight 1-5 g)
    are:

                                                          
                                   Per cent recovery
         Crop
                             Chlorobenzilate  Chloropropylate
                                                          
    Green beans              73-100

    (continued)
                                                          
                                  Per cent recovery
         Crop
                             Chlorobenzilate  Chloropropylate
                                                          
    Maize (ears)             80-120

    Maize (foliage)          80-95

    Ground nuts              78-80

    Citrus (peel)                               89-110

    Citrus (pulp)                               70-80

    Pears (peel)                                90-100

    Pears (pulp)                                100-110

    For oleagenous samples such as nuts, seeds and citrus peel, an
    additional petroleum ether-acetonitrile partitioning step is
    necessary.

    Using the described clean-up procedure no interference from DDT and
    DDD is encountered.

    National tolerances

                                                                     
         Country        Crop                           Tolerance (ppm)
                                                                     

         Canada         apples, pears, citrus fruit,
                        cantaloupes                     8

         Netherlands    fruit and vegetables            2

         New Zealand    fruit and vegetables            5

         United States
         of America     apples, pears, citrus fruit,
                        melons                          5
                        almonds, walnuts                0.2
                        almond hulls                   15
                        cotton-seed                     0.5
                        meat, fat and meat by-products  0.5
                        of cattle and sheep
         (United States of America Federal Register)
                                                                     

    RECOMMENDATIONS FOR TOLERANCES AND PRACTICAL RESIDUE LIMITS

    Appraisal

    Chlorobenzilate is a persistent and specific acaricide used on a
    fairly wide range of crops. In many instances it is active against
    mites which have developed resistance to other acaricides.

    The compound is non-toxic to bees, and may be usefully applied in
    integrated control schemes. Although the compound is registered in
    many countries, little information was available on the extent of the
    use in these countries. Many of the data furnished are based upon
    experiments which have been conducted in the United States of America.
    Furthermore, no information was available on the total composition of
    the technical product.

    The compound has not been detected in total diet studies in the United
    States of America. There was a lack of data on the disappearance of
    the compound and the disappearance of residues during storage and
    processing. Information is required on the possible carry-over of the
    residue into wine before tolerances for grapes can be recommended.
    Although data were provided on residues in milk following feeding at
    excessively high dosages to dairy cattle for a short period of time
    (16 days), there were no data furnished on possible residues in milk
    following the feeding of treated feed at normal residue levels for
    longer periods. However, the residue occurring as the result of these
    high-level feeding trials was at the limit of detection of the
    analytical method (0.05 ppm) and it would not be expected that a
    higher residue level would result from feeding lower levels for longer
    periods in view of the fact that the compound is not cumulative.

    In animals the compound is metabolized to form 4,4'-dichlorobenzilic
    acid. No information is available on the nature of the terminal
    residues in plants and in animal products.

    A referee method of analysis has not been established, although
    gas-liquid chromatography would seem to be most suitable for this
    purpose, but must be further developed by collaborative studies.
    Comparative evaluation of the different detectors used in gas
    chromatographic methods, and evaluation of different methods of
    extraction are needed.

    Recommendations

    The following temporary tolerances (to be in effect until 1972) are to
    apply to raw agricultural products moving in commerce unless otherwise
    indicated. In the case of fruits and vegetables, the tolerances should
    be applied as soon as practicable after harvest and in any event prior
    to actual retail to the public. In the case of commodities entering
    international trade, the tolerances should be applied by the importing
    country at the point of entry or as soon as practicable thereafter.
    The tolerances are for the parent compound only.

                                                        
         apples, pears (whole fruit basis)   5.0 ppm

         citrus (whole fruit basis)          1.0 ppm

         melons, cantaloupes                 1.0 ppm

         almonds, walnuts                    0.2 ppm
                                                        

    Further work or information

    Required before 30 June 1972

    1. Information on the composition of the technical product.

    2. Information on the nature of terminal residues in plants, animals,
    and their products.

    3. Data from countries other than the United States of America on the
    required rates and frequencies of application, pre-harvest intervals,
    and the resultant residues.

    4. Further data on the disappearance of residues in soils, in plants,
    and in plant products during storage and processing.

    5. Data on the possible carry-over of residues into wine as a result
    of the treatment of grapes.

    6. Further data on the occurrence of residues in milk after feeding
    dairy cows at normal residue levels of the compound in the feed.

    7. Comparative evaluation of the different detectors used in gas
    liquid chromatographic methods and of different methods of extraction
    for regulatory purposes.

    Desirable

    1. Collaborative studies to establish a referee method.

    2. Metabolic studies in animals.

    3. Investigation of possible testicular effects and long-term studies
    in species other than the rat on the incidence of neoplasms.

    REFERENCES

    Blinn, R. C. and Gunther, F. A. (1963) The utilization of infrared and
    ultraviolet spectrophotometric procedures for assay of pesticide
    residues. Residue Reviews 2: 99-152

    Cummings, J. G. (1966) Pesticides in the total diet. Residue Reviews
    16: 30-45

    Domenjoz, R. (1965a) Chlorbenzilat Toxizität bei chronischer
    Verabreichung. Institute of Pharmacology, Rheinische
    Friedrich-Wilhelm's University, Bonn. Unpublished report.

    Domenjoz, R. (1965b) Dichlorbenzilsäure Toxizität bei chronischer
    Verabreichung. Institute of Pharmacology, Rheinische
    Friedrich-Wilhelm's University, Boon. Unpublished report.

    FAO/WHO. (1965) Evaluation of the toxicity of pesticide residues in
    food. FAO Mtg Rept No. PL:1965/10/1; WHO/Food Add./27.65

    Gasser, R. (1952)  Über zwei neue Akarizide aus der Gruppe der Di-(p-
    chlorphenyl)-karbinole. Experientia, 8: 65-67

    Geigy S.A., J.R. (1968) Chlorobenzilate working paper. Unpublished 
    report.

    Gubler, W. et al. (1953) Schweizerische Bienenzeitung, 7: 268

    Harris, H. J. (1955) Colorimetric determination of ethyl
    4,4'-dichlorbenzilate (chlorobenzilate) as a spray residue. J. Agr.
    Food Chem., 3: 939-941

    Hazleton Laboratories Inc. (1953a) Geigy 338, technical. Chronic
    feeding - rats.  Unpublished report

    Hazleton Laboratories Inc. (1953b) Geigy 338, technical feeding
    studies - rats.  Unpublished report

    Hazleton Laboratories Inc. (1964) Method and development for the 
    analysis of chloropropylate and chlorobenzilate in biological fluids
    and tissue specimens. Metabolic distribution and excretion of
    chloropropylate and chlorobenzilate in dogs. Unpublished report

    Hazleton Laboratories Inc. (1965) Chlorobenzilate. Two year dietary
    feeding study - purebred beagles. Unpublished report

    Horn, H. J., Bruce, R. B, and Paynter, O.E. (1955) Toxicology of 
    chlorobenzilate. J. Agr. Food Chem., 3: 752-756

    Industrial Bio-Test Laboratories. (1965) Report to Geigy Chemical
    Corp. Acute toxicity studies on chlorobenzilate 25W. Unpublished
    report

    Margot, A. and Stammbach, K. (1964) Chlorobenzilate; in: Zweig, G.,
    1964. Analytical methods for pesticides, plant regulators and food
    additives. Academic Press, London and New York, Vol. 2, 65-73

    Mattson, A. M., Beaudoin, R. L. and Schneller, J. (1965) Comparison of
    urinary metabolites in dogs after administration of chlorobenzilate or
    chloropropylate. Analytical Dept. of Geigy Research Laboratories.
    Unpublished report

    Mattson, A. M. and Schneller, J. (1966) Chlorobenzilate residues in
    sheep and cattle tissues. Unpublished report of the Analytical
    Department of Geigy Research Laboratories, Division of Geigy Chem.
    Corp., Ardsley, New York.

    Murphy, R., Kahrs, R. and Mattson, A. M. (1966) Dissipation of
    residues of chlorobenzilate and chloropropylate on apples. Unpublished
    report of the Analytical Department of Geigy Research Laboratories,
    Division of Geigy Chem. Corp., Ardsley, New York

    United States of America Federal Register, 27, F.R. 12092, pav.
    120-129

    United States of America Department of Agriculture. (1966) Summary of
    registered pesticide chemical cases. 1st October

    Woodard. (1960) Examination of milk for residues following feeding of 
    chlorobenzilate to dairy cows. Unpublished report, Woodard Research
    Corp.

    Woodard. (1965a) Chlorobenzilate. Safety evaluation on fish and wild 
    life. (Bobwhite quail, mallard ducks, rainbow trout, sunfish,
    goldfish, oysters). Unpublished report, Woodard Research Corp.

    Woodard. (1965b) Chlorobenzilate. Three generation reproduction study
    in the rat. Unpublished report, Woodard Research Corp.

    Woodard. (1965c) Safety evaluation and determination of the amount of
    chlorobenzilate that might appear in the tissues of sheep and
    beef-cattle fed this material in the diet for four weeks. Unpublished
    report, Woodard Research Corp.

    Woodard. (1966) Chlorobenzilate. Safety evaluation by dietary feeding
    to rats for 104 weeks. Unpublished report, Woodard Research Corp.
    


    See Also:
       Toxicological Abbreviations
       Chlorobenzilate (ICSC)
       Chlorobenzilate (FAO Meeting Report PL/1965/10/1)
       Chlorobenzilate (WHO Pesticide Residues Series 2)
       Chlorobenzilate (WHO Pesticide Residues Series 5)
       Chlorobenzilate (Pesticide residues in food: 1977 evaluations)
       Chlorobenzilate (Pesticide residues in food: 1980 evaluations)
       Chlorobenzilate (IARC Summary & Evaluation, Volume 5, 1974)
       Chlorobenzilate (IARC Summary & Evaluation, Volume 30, 1983)