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    FAO/PL:1969/M/17/1

    WHO/FOOD ADD./70.38

    1969 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
    Group on Pesticide Residues, which met in Rome, 8 - 15 December 1969.

    FOOD AND AGRICULTURE ORGANIZATION OF THE UNITED NATIONS

    WORLD HEALTH ORGANIZATION

    Rome, 1970

    QUINTOZENE

    IDENTITY

    Chemical name

    pentachloronitrobenzene

    Synonyms

    PCNB, Brassicol(R), Terrachlor(R), Tritistan(R), Folosan(R),
    Botrilex(R).

    Structural formula

    CHEMICAL STRUCTURE 

    Other relevant chemical properties

    Colourless crystalline needles practically insoluble in water, soluble
    in benzene and chloroform. Technical quintozene is usually 97-99
    percent pure. The main impurity, is hexachlorobenzene (1.5%) together
    with lesser amounts of pentachlorobenzene and tetrachloronitrobenzene.

    Vp 11.3 × 10-5mm Hg at 25°C. Quintozene shows high stability in the
    soil. Quintozene is converted to pentachloroaniline (PCA) in moist
    soil, the metabolite having somewhat lower fungicidal activity. In
    animals the metabolites are pentachloroaniline and mercapturic acid
    (Betts et al., 1955).

    EVALUATION FOR ACCEPTABLE DAILY INTAKE

    BIOCHEMICAL ASPECTS

    Fat samples from groups of ten rats (five males and five females) fed
    diets containing 63.5, 635, 1250, or 2500 ppm of technical quintozene
    for three months were examined for storage of quintozene. The apparent
    storage ranged from an average of 43 ppm in the fat for the 63.5 ppm
    diet to 1234 ppm for the 2500 ppm diet, there being a relatively
    linear relationship between the levels of fat storage to the
    concentration of quintozene in the diet. However, the neutron
    activation method of analysis which was used would have shown the
    presence of other chlorinated compounds as well an quintozene
    (Finnegan et al., 1958).

    Tissues from an unspecified number of dogs fed 5 or 1,080 ppm of
    technical quintozene in their diet for 2 years were analysed by gas
    chromatography for residues of quintozene and its metabolites. No
    quintozene was found in fat, muscle, kidney, or liver tissues but two
    metabolic products identified as pentachloroaniline and
    methyl-pentachlorophenyl sulfide were found in these tissues.
    Pentachloroaniline was found only in the fat and liver and in amounts
    of less than 1 ppm for both dose-levels. Methyl-pentachlorophenyl
    sulfide was found in the fat and liver of rats fed both dose levels
    and was present as well in kidney and muscle in the 1080 ppm group,
    the largest amount being 2.5 ppm in the fat of animals fed that level.
    In another study on fat from an unspecified number of rats fed 50 or
    500 ppm of technical quintozene in their diet for seven months, there
    was less than 1 ppm of either of the metabolites in the fat of the
    rats fed 50 ppm of quintozene, and approximately 1 ppm of
    pentachloroaniline and 5 ppm of methyl-pentachlorophenyl sulfide for
    the 500 ppm group (Kuchar et al., 1969).

    Pentachloroaniline and another metabolite, a mercapturic acid, have
    been isolated in urine from rabbits treated with quintozene. With a 2
    g. dose an average of 62 percent of quintozene was unabsorbed and
    excreted in the faeces. The average percentages excreted in urine as
    pentachloroaniline and N-acetyl-S-pentachlorophenyl-L-cycteine were 12
    and 14 percent respectively (Betts et al., 1955).

    TOXICOLOGICAL STUDIES

    Special studies on reproduction

    A three-generation reproduction study was conducted with rats
    receiving technical quintozene in their diet in concentrations of 0,
    5, 50 and 500 ppm. Groups of 20 females were used and 2 litters were
    produced in each generation. No significant differences were found
    between the control- and quintozene-treated rats with respect to
    fertility, gestation, viability or lactation indices, or in
    weaning-weights. Histopathologic examination of the tissues of 10 pups
    of each sex from the F2b generation showed no effect from the
    treatment (Borzelloca and Larson, 1968b).

    Special studies on carcinogenicity

    Groups of 18 mice of each sex from two hybrid strains of mice were
    given quintozene (the specifications not given) from 7 days of age for
    18 months. The dose of 464 mg/kg was given to the mice by stomach tube
    from the seventh day of age to the time weaning at four weeks of age
    and thereafter the chemical was added to the diet in a corresponding
    amount of 1,206 ppm. This level was a maximum tolerated dose for the
    mice. There was a significantly elevated incidence of tumours, mostly
    hepatomas, in both strains of mice (Innes. et al., 1969).

    Acute toxicity

                                  LD50
    Animal      Route        mg/kg body-weight      References
                                                                           

    Rat (M)     oral         1710*                  Finnegan, et al., 1958
                             (oil solution)

    Rat (F)     oral         1650*                  Finnegan, et al., 1958
                             (oil solution)

    Rat         oral         >30,000                Wit, et al., 1957
                             (aqueous suspension)

    Rat         i.p.         5,000                  Wit et al., 1957
                             (aqueous suspension)
                                                                           

    * technical grade; defined as: pentachloronitrobenzene ... 98.2 percent
                                   hexachlorobenzene       ...  1.4 percent
                                   traces of tetrachloro-
                                   nitrobenzene and pentachlorobenzene

    Short-term studies

    Dog

    Groups, each of three mongrel dogs, of unspecified sex were placed on
    diets containing 25, 200 or 1,000 ppm of technical quintozene for one
    year. No adverse effect was noted on body-weight or survival. No
    haematologic changes were seen. Histopathologic changes were confined
    to liver-cell enlargement with pale-staining cytoplasm at all
    dose-levels, but there was no increasing severity of the lesions with
    increasing exposure to quintozene (Finnegan et al., 1958).

    Groups of four dogs of each sex were placed on diets containing 0, 5,
    30, 180, or 1,080 ppm of technical quintozene for two years. No
    adverse effect was noted on body-weight or survival. Increased
    liver-weights, elevated serum-alkaline phosphatase and a moderate
    degree of cholestatic hepatosis with secondary bile nephrosis occurred
    in the dogs on the 1,080 ppm level. A minimum degree of cholestatic
    hepatosis with secondary bile necrosis occurred at 180 ppm. No effect
    was noted in the dogs fed 5 and 30 ppm of quintozene (Borzelloca and
    Larson, 1968a).

    Groups of six dogs, each comprising three male and three female
    animals, were fed diets containing 0, 500, 1,000 or 5,000 ppm of
    quintozene (the specification not given) for two years. Liver changes
    occurred in all groups with the degree of damage related to the dose.
    The 5,000 ppm level produced severe liver damage including fibrosis,
    narrowing of hepatic cell cords, increased size of the periportal
    areas and thick leucocyte infiltration. At the 1,000 and 500 ppm

    dose-levels the changes were similar to those at the 5,000 ppm level
    but to a lesser degree. The highest dose-level produced atrophy of
    bone-marrow and reduced haematopoiesis (Hoechst, 1968).

    Rat

    Groups of 35 rats of each sex were fed diets containing 0, 63.5, 635,
    1,250, 2,500 or 5,000 ppm of technical quintozene for three months.
    Growth and survival were adversely affected in both sexes at the
    dose-level of 5,000 ppm and in males growth was suppressed at 2,500
    ppm. Liver to body-weight ratios were elevated at all dietary levels
    except in the females fed 63.5 ppm. No haematologic changes were seen,
    and histopathologic changes were limited to fine vacuolization of
    liver-cell cytoplasm at 5000 ppm (Finnegan et al., 1958).

    An unspecified number of young rats were fed diets containing 0 or
    2,000 ppm of quintozene for 10 weeks. No gross effects, other than a
    decreased growth rate in the males, were noted (Wit, et al., 1957).

    Groups of 20 rats each comprising 10 male and 10 female animals were
    fed diets containing 0, 1,000, 5,000 or 10,000 ppm of quintozene (the
    specification not given) for 90 days. The animals grew slightly less
    than controls at the 5,000 ppm dose-level and markedly less at the
    10,000 ppm level (Hoechst, 1964).

    Long-term studies

    Rat

    Groups of 10 rats of each sex were fed dicta containing 0, 25, 100,
    300, 1,000 or 2,500 ppm of technical quintozene for two years. Growth
    suppression occurred in the females at dose-levels of 100 ppm and
    above; however, in the males growth depression occurred only at 2,500
    ppm level. Haematologic and histopathologic observations in the test
    animals were similar to the control group (Finnegan, et al., 1958).

    OBSERVATIONS IN MAN

    Quintozene (75 percent wettable powder) did not cause primary
    irritation when applied to the skin of 50 human subjects; in 13 of
    them sensitization was produced (Finnegan et al., 1958).

    COMMENT

    The acute and short-term studies and the reproduction studies in rats
    are considered adequate. A preliminary report of studies in mice
    indicates a potential for carcinogenicity in animals given a high dose
    and further work is needed in other species. In the two-year study in
    dogs severe morphologic changes were observed in the liver and
    bone-marrow in the high dose-level groups. Furthermore, the apparent
    erratic effect on growth an indicated in the studies with rats is not
    explained. Additional studies should be done to delineate the exact
    cause of these effects. Insufficient information in available on the

    biological fate of the compound. For these reasons only a temporary
    acceptable daily intake is established based on the two-year study in
    the rats.

    TOXICOLOGICAL EVALUATION

    Level causing no significant toxicological effect

    Rat:  25 ppm in the diet, equivalent to 1.25 mg/kg body-weight/day

    ESTIMATE OF TEMPORARY ACCEPTABLE DAILY INTAKE FOR MAN

    0-0.001 mg/kg body-weight

    RESIDUES IN FOOD AND THEIR EVALUATION

    USE PATTERN

    Pre-harvest treatments

    Quintozene is a fungicide mainly used for soil treatment or for
    treatment of seeds and transplants but some crop applications are
    recommended. The following table gives a review of application rates
    of quintozene and recommended pre-harvest intervals.

        TABLE I
                                                                                            

                                                                                Pre-harvest
    Crop              Rate               Limitations                            interval days
                                                                                            

    Bananas           1.63% paste        Apply to stems only - not to fruit

    Beans             5.0 kg/ha          Apply to foliage                             21
                      0.5 g/kg seed      Seed treatment                               70
                      50g/100m of row    Spray base of plants                         21
                      40g/100m of row    Soil treatment only                          70

    Cruciferous
    vegetables        60 kg/ha           Pre-planting                                 70
                      470g/100m row      Row application prior to transplanting       70

    Corn              0.5g/kg seed       Seed treatment                               70

    Garlic            150g/100m row      Soil treatment at planting                   90

    Lettuce (head)    150g/100m row      When plants 5-7.5 cm tall                    30
                      30g/100m row       2 treatments at 10 day intervals             20

    Onions            40 kg/ha           Pre-planting

    TABLE I (cont'd)
                                                                                            

                                                                                Pre-harvest
    Crop              Rate               Limitations                            interval days
                                                                                            

    Peanuts           250g/100m row      Pre-planting                                 90
                      200g/100m row      At pegging time                              60

    Peas              1g/kg              Seed treatment

    Peppers           70g/100m row       At planting time                             70

    Potatoes          22 kg/ha           Prior to planting                            70
                      140g/100m row      At planting time                             70

    Safflower,
    Sorghum,
    Soybeans,
    Sugarbeet         1.5 g/kg           Seed treatment only                          70

    Tomatoes          160g/100m row      Prior to transplanting                       70

    Wheat             0.5g/kg seed       Seed treatment                              150
                                                                                            
    
    Post-harvest treatments

    No post-harvest treatments with quintozene are known.

    Other uses

    Quintozene is used for control of fungi in alfalfa, clover, cotton,
    ornamentals, bulbs, lawns, mushrooms and coffee crops.

    RESIDUES RESULTING FROM SUPERVISED TRIALS

    Detailed residue data are available from United States trials with
    quintozene on important crops and have been deposited with FAO. Rates
    of application are similar to those given below. The typical data
    presented below are representative:

        TABLE II
                                                                                        
                                                Post-
                                  Number        treatment          Residues (ppm)
                        Rate      of            interval
    Crop                kg/ha     treatments    days          Range             Average
                                                                                        

    Beans                 1          1             60         0.003-0.004        0.003
                         10          1             60         0.005-0.006        0.005

    Beans                 1          1             60         <0.01             <0.01

    Beans                 1.5        1             60         <0.01             <0.01

    Beans (small
     white dry)           1          1            150         <0.01             <0.01

    Beans (string)        0.5        1             70         <0.01             <0.01

    Beans (navy)          8          4            120         0.003-0.152        0.07

    Beans (Lima)          1.5        1             90         <0.01

    Broccoli             20          1                        0.003-0.018        0.012
                         40          1            140         0.002-0.021        0.013

    Cabbage              20          1            140         0.000-0.014        0.007
                         40          1            140         0.000-0.020        0.007

    Cottonseed            0.3        1             70         0.000-0.017       <0.017

    Cottonseed            5.0        1            150         <0.012            <0.012

    Cottonseed            2.5        1            150         <0.012            <0.012
                          5.0        1            180         0.004-0.032        0.014

    Lettuce heads       100          1            180         0.00 -0.01         0.00

    Lettuce outer
      leaves            100          1            180         0.02 -0.11         0.06

    Lettuce heads                    2              8         0.00               0.00
                                     2             16         0.00               0.00

    Lettuce             18G          1             60         0.03 -0.05         0.03
      (Greenhouse)     18WP          1             60         0.20 -0.30         0.26
                       18WP          1             70         0.09 -0.139        0.104
                        18G          1             70         0.048-0.093        0.058

    TABLE II
                                                                                        
                                                Post-
                                  Number        treatment          Residues (ppm)
                        Rate      of            interval
    Crop                kg/ha     treatments    days          Range             Average
                                                                                        

    Mushrooms             1.5        1              1         9.57 -9.68         9.6
                          1.5        1              3         2.75 -2.97         2.8
                          1.5        1              7         1.30 -1.36         1.34

    Peanuts,kernels      10          1            130         0.063-0.154        0.104
      kernels           100          1            130         0.208-0.212        0.210

    Peanut shells       100          1            130         4.60 -5.21         4.96

    Peppers              50          1             75         0.0  -0.008        0.002
                         50          2             35         0.0  -0.009        0.003

    Potatoes             10          1            130         0.01 -0.066        0.027
                         10          1            130         0.066-0.125        0.088
                         10          1            130         0.00 -0.002        0.001
                         20          1            130         0.001-0.005        0.002

    Tomatoes              3          2             50         0.00 -0.08         0.02
                         10          1             70         0.00 -0.01         0.01
                         50          1            100         0.00 -0.02         0.01
                                                                                        
    
    FATE OF RESIDUES

    In animals

    No data was available to show the residues in animal tissues or animal
    products from the feeding of forage grown in soil treated with
    quintozene. In view of the stability of the compound, its solubility
    in lipids and its resistance to metabolism it seems highly likely that
    significant residues of quintozene or pentachlor - derivatives do
    occur in animal fats, milk and eggs.

    Quintozene was reported in trace amounts in dairy produce and in oils,
    fats and shortening in the U.S. total diet studies.

    A paper by Kuchar et al. (1969) not available for consideration at the
    time the original data was reviewed reports analytical studies of
    metabolism of quintozene in beagle dogs, rats and plants.

    Tissues from beagle dogs fed food containing 1,080 ppm quintozene in
    their rations for 2 years were examined by GLC methods.
    Pentachloroaniline (PCA) was identified in blood. Fat, liver, urine
    and faeces yielded pentachloronitrobenzene (quintozene);

    pentachlorobenzene (PCB); hexachlorobenzene (HCB) and
    pentachloroaniline (PCA) and methyl pentachlorophenyl sulphide.
    Quintozene was not detected in muscle, kidney, fat or liver of dogs
    receiving 1,080 ppm in their diet over 2 years (234 gms quintozene in
    all). HCB was the most prominent residue yielding 194 ppm in fatty
    tissue. PCB occurred in a significant amounts only in fat (5.15 ppm)
    and PCA only in faeces. A small amount of the quintozene fed is
    excreted in the faeces (14 ppm).

    No metabolites, only HCB, were found in tissues of rats fed quintozene
    for 7 months at 500 ppm.

    In plants

    There is evidence of a slight systemic uptake by plants revealed by
    analysis by spectrophotometric methods following application of
    quintozene to soil. The following table gives typical examples from
    the extensive data available (Olin Mathieson, 1969).

    TABLE III
                                                                           

                                                   Residues
                                                                Seeds or
                   Applied     Soil      Roots     Leaves        fruit
    Crop           kg/acre     ppm       ppm       ppm            ppm
                                                                           

    Beans             1        1.2        0.59     0.034         0.003

                      1.5      0.68       1.12     0.017         0.013

                      1.5      0.59       2.27     N.D.          0.004

    Snap beans        1.0      9.2        9.0      0.004            -
                      1.5      3.4        7.0      0.09             -

    String beans      0.75       -        0.94     0.288            -
                      1.0        -        3.62     0.221            -
                      1.5        -        2.37     0.461            -

    Field beans       1.5      7.77      19.33     0.12             -

    Lettuce           4.0        -          -      0.0              -
     (field)         15.0        -          -      0.02             -
                     50.0        -          -      0.00             -
                    100.0        -          -      0.00             -
                    100          -          -      0.06 outer       -
                                                        leaves

    TABLE III
                                                                           

                                                   Residues
                                                                Seeds or
                   Applied     Soil      Roots     Leaves        fruit
    Crop           kg/acre     ppm       ppm       ppm            ppm
                                                                           

    Lettuce          18 dust     -          -      0.05             -
     (greenhouse)
                      0.4 Spray  -          -      0.03             -
                     18 Granule  -          -      0.02             -

    Cabbage           2.0        -          -      0.007            -
                      2.0        -          -      0.008            -

    Tomatoes          6.0        -          -         -          0.02
                     50.0        -          -         -          0.01

    Potatoes         10.0        -          -         -          0.03
                     10.0        -          -         -          0.008

    Alfalfa          10          -          -      0.02             -
                     20          -          -      0.05             -

    Peanut           10          -          -      0.235            -
                      1.0        -        0.44     0.003            -
                                                                           
    
    Gorbach and Wagner (1967) showed, by using highly sensitive GLC
    techniques capable of detecting both quintozene and PCA that potatoes
    growing in soil treated with quintozene at rates from 25 to 800 kg/ha
    showed significant residues of quintozene in the skin (up to 3 ppm at
    800 kg/ha) but only insignificant traces of PCA (up to 0.4 ppm) in the
    skin. The flesh of these potatoes contained no detectable residues of
    quintozene (less than 0.01 ppm) and less than 0.1 ppm of PCA and
    unidentified metabolites.

    Gorbach (1969) reports that the most recent studies reveal no evidence
    of translocation from soil into green parts of leafy plants. A
    carefully controlled experiment, where all possible contamination by
    splash or vapour was eliminated, revealed no uptake by parsley growing
    in quintozene treated soil.

    Kuchar et al. (1969) reports that the metabolic pathway in plants
    appears to be the same mechanism as in animals. Studies using cotton
    seed planted in soil containing 300 ppm quintozene yielded the
    following residues in the young cotton plants two weeks later: (1)
    pentachloranitrobenzene (quintozene) 155 ppm; (2) pentachlorobenzene
    4 ppm; (3) methyl pentachlorophenyl sulphide 3 ppm; (4)
    hexachlorobenzene 5 ppm; (5) pentachloroaniline 1.1 ppm; and (6) 2, 3,

    4, 5 - tetrachloronitrobenzene 0.018 ppm. Residues (2), (4) and (6)
    may have originated partly from impurities in the technical grade
    quintozene (97.8% PCNB; 1.8% HCB; 0.1% PCB and 0.4% TCNB).

    These authors were able to show that the two unidentified materials
    reported by Gorbach and Wagner (1967) were in fact hexachlorobenzene
    (HCB) and the metabolite methyl pentachlorphenyl sulphide.

    In soils

    Quintozene appears to persist for long periods in the soil as disease
    control may be as long an 12 months (Hertzfield, 1967). Ko and Farley
    (1969) show that in moist soil quintozene is gradually converted to
    pentachloroaniline (PCA) and the conversion was greatly enhanced by
    submergence of the soil in water. PCA was stable in both moist and
    submerged soil and was inhibitory to micro-organisms but to a lesser
    extent than quintozene. The long term action of quintozene is partly
    due to its conversion to PCA.

    Quintozene remains unchanged in sterilized, moist soil but disappears
    from submerged sterilized soil with a half life of three weeks. No PCA
    was detected in sterilized submerged soil. Studies by Ko and Farley
    (1969) showed that soil micro-organisms are responsible for the
    conversion of quintozene to PCA.

    Evidence of residues in food in commerce or at consumption

    The only data available on quintozene residues in food moving in
    commerce was gathered in the U.S.A. The U.S.D.A./H.E.W. 1968 reports
    that of 9,789 samples of leaf and stem vegetables produced in the
    U.S.A. and examined for a wide range of pesticides, 89 samples (0.89%)
    contained quintozene at levels ranging from trace quantities to
    greater than 2.0 ppm. The following shows the range:

                                         
            ppm                    %
                                         

    Trace   -    0.03             0.42

    0.04    -    0.5              0.19

    0.51    -    1.0              0.1

    1.01    -    2.0              0.04

    Above   -    2.0              0.14
                                         
                                  0.89%



    Quintozene was reported to occur in trace amounts in the fat of dairy
    produce and at a level of 0.021 ppm in a composite sample of oils,
    fats and shortening in the total diet studies conducted in the U.S.A.
    in 1963-68 (Duggan 1968, Corneliussen 1969). The total intake in the
    diet was calculated to be no more than trace amounts (less than 0.001
    mg).

    METHODS OF RESIDUE ANALYSIS

    A review of analytical methods is given in the book by Zweig (1964).
    Klein and Gajan (1961) have carefully compared a colorimetric, a
    polarographic and a gas chromatographic - colometric method for
    residue analysis on lettuce, cabbage and beans. The colorimetric
    method of Ackermann et al. (1958) is reported to be the most accurate
    in the range below 5 ppm with a recovery of 94%. The latter method was
    improved by Ackermann et al. (1963). This method is however the
    slowest of the three methods and does not differentiate quintozene
    from tetrachlorobenzene. The polarographic method (Bache and Lisk,
    1960; Klein and Gajan, 1961 and Gorbach, 1961) is the most rapid
    because of less stringent cleanup requirements. Gorbach (1961) used a
    sublimation step in the cleanup before the polarographic determination
    and thus eliminated many of the interfering substances.

    With the polarographic method, recoveries averaged 81%. with a
    standard deviation of 12%. The gas chromatographic-colometric method
    (Klein and Gajan, 1961) yielded average recoveries of 90% with average
    deviation of 15%.

    For proper identification, extracts should be checked for quintozene
    by paper chromatography (Mitchell, 1957, 1958) or by thin layer
    chromatography (Gorbach, 1967). In the latter paper, methods are given
    to separate and identify the metabolite pentachloroaniline.

    All three methods can be recommended and can be selected according to
    equipment available.

    (a) The colorimetric method (Ackermann et al., 1963). The quintozene
    residue in fat-free extract is hydrolized to nitrite with alcoholic
    potassium hydroxide, the nitrite is used to diazotize procaine
    hydrochloride and the diazonium salt coupled with l-naphthylamine to
    give a magenta solution having absorption maximum at 525 mu.

    (b) Polarographic method (Bache and Lisk, 1960; Klein and Gajan,
    1961; Gorbach, 1961). The crop material is extracted with hexane. The
    extract is filtered and dried and a part of the co-extractives are
    removed by freezing and adsorption on Attaclay.

    Chromatography of the concentrated extract using Florisil removes the
    remainder of the interfering substances. The solvent is then
    evaporated and the residue dissolved in isopropyl alcohol. After
    adding sodium acetate and acetic acid for supporting electrolyte and
    deoxygenating the solution, the polarogram in recorded from 0.00 to

    1.15 volts against saturated calomel electrode. The half-wave
    potential for quintozene in -0.47 volts.

    The later papers recommend a number of modifications to the
    polarographic procedure.

    (c)  Gas Chromatographic - Microcolometric Method (Klein and Gajan,
    1961; Gorbach, 1961). The extraction is carried out as described for
    the polarographic method. The concentrated extract is evaporated to
    dryness and the residue dissolved in hexane is injected into the
    instrument.

    The multi-detection procedure for determining chlorinated residues in
    non-fatty foods based on JAOAC, 49 222 (1966) paragraph 24.213 which
    in official for a number of pesticides is satisfactory for the
    determination of quintozene residues.

    A method using electron capture gas chromatography (Methratta T.P. et
    al., 1967) suitable for determining quintozene residues in plants,
    seeds and soil has a sensitivity of 0.01 ppm and is relatively free of
    interference from plant extracts. The method is probably suitable for
    development towards greater sensitivity.

    NATIONAL TOLERANCES
                                                                                       
    Country                      Crop                           Tolerance (ppm)
                                                                                   

    Germany (Fed.Rep.)           Cabbage, lettuce               1.0

                                 onions, cucumber               1.0

                                 horse radish                   1.0

                                 leaf vegetables                3.0

                                 bananas (peeled)               0.1

    Netherlands                  Fruit and vegetables           5.0

    United States of America     Bananas, beans, broccoli,      Originally on "no
                                 brussels sprouts, cabbage,     residue basis". At
                                 cauliflower, cotton,           present under review.
                                 garlic, lettuce, peanuts,
                                 peas, peppers, potatoes,
                                 tomatoes, wheat.
                                                                                   
    
    APPRAISAL

    Quintozene or pentachloronitrobenzene (PCNB) is a versatile fungicide
    used chiefly against soil fungi in agriculture and horticulture. It

    was first developed in 1930 as a seed dressing for wheat. It is used
    in many countries as a soil fungicide against Sclerotinia,
    Rhizoctonia, Botrytis, Sclerotium, Fusrium and similar fungi of
    vegetable and forage crops. Application by means of wettable powder,
    emulsion concentrate or dust ranges from 10 to 55 kg/ha or 15 to 600g
    per 100m of row. Seed dressings applied in the form of dust range from
    30g to 300 g per 100 kg of seed. Treatments other than those applied
    to the soil are usually aimed at the base of the plant but some
    foliage applications are made, particularly to lettuce, beans and
    mushrooms. Pre-harvest intervals are four to eight weeks.

    The data available to the meeting were obtained solely in the United
    States of America and did not include information about residues
    following use elsewhere. Some information is available about residues
    in foods in commerce.

    Quintozene has high stability in soil and under neutral conditions
    remains stable for exceptionally long periods.

    The literature includes a number of methods of residue analysis based
    on electron-capture gas chromatography and spectrophotometric methods.
    The sensitivity of the methods is reported to be 0.01 ppm but the
    spectrophotometric method does not determine the metabolite
    pentachloroaniline (PCA). Quintozene and PCA may be determined by
    multi residue methods for chlorinated compounds but no regulatory
    methods have been evaluated, and there is reason to believe that the
    recovery from many food commodities may be low unless special
    provision is made for extraction and cleanup. Further work on the
    development of an acceptable regulatory method is required.

    RECOMMENDATIONS FOR TOLERANCES, TEMPORARY TOLERANCES
    OR PRACTICAL RESIDUE LIMITS

    TEMPORARY TOLERANCES (effective to 1973)

    Residues of the metabolite pentachloroaniline to be included.

                                                   
    Bananas (pulp)                         0.01 ppm
            (whole)                        1.0

    Beans                                  0.01

    Beans (navy)                           0.2

    Broccoli                               0.02

    Cabbage                                0.02

    Cottonseed                             0.03

    Lettuce                                0.3

    (cont'd)
                                                   

    Mushrooms                             10.0

    Peanuts (kernels)                      0.3
            (whole)                        5.0

    Peppers                                0.01

    Potatoes                               0.2

    Tomatoes                               0.1
                                                   

    FURTHER WORK OR INFORMATION

    REQUIRED (before June 1973)

    1. Carcinogenicity studies in two species of animals.

    2. Studies to explain the cause of growth depression in rats and the
       effect on liver and bone-marrow in dogs.

    3. Further studies on the metabolism and on the metabolites,
       particularly pentachloroaniline.

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

    5. Information on residues in edible animal tissues and in animal
       products resulting from the feeding of plant products (including
       forage) treated with quintozene in accordance with normal 
       agricultural practice.

    6. Information on the frequency and level of quintozene residues in
       food commodities in commerce.

    7. Information on the level of metabolites, particularly
       pentachloroaniline in plants and animals.

    DESIRABLE

    1. Development of analytical methods for greater sensitivity and
       evaluation for regulatory purposes.

    2. Information on the residue levels in root crops, especially
       carrots, grown in soil treated previously with quintozene in crop
       rotation.

    REFERENCES

    Ackermann, H.J. et al. (1958) Spectrophotometric determination of
    pentachloronitrobenzene on food and forage Crops. J. Agric. and
    Food Chem. 6:747-50 (Oct.)

    Ackermann, H.J. et al. (1963) Modifications to the spectrophotometric
    analysis of PCNB in Soil and Crops. J. Agric. and Food Chem.
    11(4) 297 (July/Aug. 1963)

    Bache, C.A. and Lisk, D.I. (1960) Journal of Agriculture and Food 
    Chemistry 8, 459

    Betts, J.J., James, Sybil P. and Thorpe, W.V. (1955) The metabolism of
    pentachloronitrobenzene and tetrachloronitrobenzene and the
    formation of mercapturic acid in the rabbit Biochem. J. 61 (4)
    611-7

    Borzelloca, J.F. and Larson, P.S. (1968a) Toxicologic study on the 
    effect of adding Terrachlor to the diet of beagle dogs for a period of
    two years. Unpub. Rept. from the Medical College of Virginia submitted 
    by Olin Mathieson Chemical Corporation

    Borzelloca, J.F. and Larson, P.S. (1968b) Three generation 
    reproduction study on rats receiving Terrachlor in their diet. Unpub. 
    Rept. from the Medical College of Virginia submitted by Olin Mathieson
    Chemical Corporation

    Corneliussen, P.E. (1969) Residues in food and feed - pesticide 
    residues in total diet samples (IV). Pesticides Monitoring Journal 2
    (4) 140-52

    Duggan, R.E. (1968) Residues in food and feed 1963-67. Pesticides
    Monitoring Journal 2 (1) 2-46

    Gorbach, S. (1961) Acta Chemica (Academiae Scientarum Hungaricae) 28 
    (1-3), 199-206

    Gorbach, S. and Wagner, U. (1967) Pentachloronitrobenzene residues in
    potatoes. J. Agric. and Food Chem. 15 (4) 654

    Gorbach, S. (1969) Personal Communication to FAO
    

    Hertzfield, E.G. (1967) Terrachlor - a new Soil Fungicide Agricultural
    Chemicals 12 30-3

    Hoechst. (1964) Toxikologische Prüfung von Pentachlornitrobenzol. 3. 
    Auf chronische Toxizität (90-Tage-Test) an Ratten. Unpub. Rept.
    prepared and submitted by Farbwerke Hoechst, AG.

    Hoechst. (1968) Chronische orale Toxizatätsprüfung von
    Pentachlornitrobenzol. 2-Jahres-Versuch an Hunden. Unpub. Rept.
    prepared and submitted by Farbwerke Hoechst AG.

    Finnegan, J.K., Larson, P.S., Smith, R.B. Jr., Haag, H.B. and
    Hennigar, G.R. (1958) Acute and chronic toxicity studies on
    pentachloronitrobenzene. Arch. int. Pharmacodyn. 114:38-52

    Innes, J.R.M., Ulland, B.M., Valerio, M.G., Petrucelli, L., Fishbein,
    L., Hart, E.R., Pallota, A.J., Bates, R.R., Falk, H.L., Gart,
    J.J., Klein, M., Mitchell, I. and Peters, J. (1969) Bioassay of
    pesticides and industrial chemicals for tumorigenicity in
    mice. A preliminary note. J. nat. Cancer Inst. 42:1101-14

    Klein, A.K. and Gajan, R.J. (1961) Methods for the determination of 
    PCNB Residues. JAOAC 44:712

    Ko, W.H. and Farley, J.D. (1969) Conversion of 
    pentachloronitrobenzene to pentachloroaniline in soil and the effect 
    of these compounds on soil Micro-organisms. Phytopathology 59 (1)
    64-7

    Kuchar, E.J., Geenty, Frances, O, Griffith, William P. and Thomas,
    Raymond J. (1969) Analytical studies of metabolism of Terraclor in
    beagle dogs, rats and plants, J. Agric. and Food Chem. 17 (6)
    1237-40

    Methratta, T.P., Montagna, R.W. and Griffith, W.P. (1967)
    Determination of PCNB in crops and soil by electron-capture gas
    chromatography. J. Agric. and Food Chem. 15 (4) 648 (July/Aug. 1967)

    Mitchell, L.C. (1957) J. Assoc. Offic. Agric. Chemists 40, 294

    Mitchell, L.C. (1958) J. Assoc. Offic. Agric, Chemists 41, 781
    

    Olin Mathieson Chemical Corporation. (1969) Research reports on
    quintozene

    United States of America. (1969) Department of Agriculture Summary of
    Registered Agricultural Pesticide Chemical Uses

    United States of America. (1968) Department of Health, Education and 
    Welfare FDA Pesticide Analytical Manual Volume 1 Section 212.1

    Wit, S.L., van Esch, G.J. and van Genderen, H. (1957) Toxicity of 
    some chloronitrobenzen compounds (trichlorodinitrobenzene,
    trichloronitrobenzene, tetrachloronitrobenzene and
    pentachloronitrobenzene) to laboratory rats and residues
    found in crops treated with these fungicides. Proceedings of
    the Fourth International Congress of Crop Protection,
    Hamburg, September 1957. Vol. 2 (Braunschweig 1960): pp.
    1665-8

    Zweig, Gunter. (1964) Analytical Methods for Pesticides and Plant 
    Growth Regulators and Food Additives Vol. III Academic Press. New
    York
    


    See Also:
       Toxicological Abbreviations
       Quintozene (EHC 41, 1984)
       Quintozene (HSG 23, 1989)
       Quintozene (ICSC)
       Quintozene (WHO Pesticide Residues Series 3)
       Quintozene (WHO Pesticide Residues Series 4)
       Quintozene (WHO Pesticide Residues Series 5)
       Quintozene (Pesticide residues in food: 1977 evaluations)
       Quintozene (Pesticide residues in food: 1995 evaluations Part II Toxicological & Environmental)