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    PESTICIDE RESIDUES IN FOOD - 1982


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    EVALUATIONS 1982





    Data and recommendations of the joint meeting
    of the FAO Panel of Experts on Pesticide Residues
    in Food and the Environment and the
    WHO Expert Group on Pesticide Residues
    Rome, 23 November - 2 December 1982

    Food and Agriculture Organization of the United Nations
    Rome 1983


    PROPARGITE

    CHEMICAL STRUCTURE 1

    Explanation

         Propargite was reviewed by the Joint Meeting of 1977 (FAO/WHO
    1978)1 and a temporary ADI of 0-0.08 mg/kg b.w. was determined. The
    JMPR requested that a carcinogenicity study be performed and submitted
    for review prior to July 1981. The subject study was not made
    available for review. The teratology study in rats was performed by
    Industrial Bio-Test Laboratories (IBT) and a replacement study has
    subsequently been provided and reviewed in this monograph addendum.

    EVALUATION FOR ACCEPTABLE DAILY INTAKE

    TOXICOLOGICAL STUDIES

    Special Study on Teratogenicity

         Groups of 20-30 pregnant Sprague-Dawley rats were administered
    propargite by gavage at levels of 0, 6, 25 or 105 mg/kg/day from days
    6 through 15 of gestation. Maize oil and aspirin served as the vehicle
    (negative) and positive control groups, respectively. On day 20 of
    gestation, all pregnant animals were sacrificed and the foetuses
    delivered by caesarean section. Maternal observations included
    cageside observations, body weights, numbers of corpora lutea,
    implantation sites, resorption sites and live and dead foetuses. Sex
    of foetuses and body weights of foetuses were also determined. Each
    foetus was examined grossly for abnormalities, as well as for detailed
    visceral and skeletal anomalies and/or variations.

              

    1  See Annex 2 for WHO and FAO documentation.

         There were no compound-related effects on maternal or foetal body
    weights, pregnancy implantations, number of live/dead foetuses or
    number of resorption sites, except in the positive control (aspirin,
    250 mg/kg) groups where both maternal and foetal weights were
    decreased, number of live foetuses per dam decreased and the number of
    resorption sites were increased. The only noticeable effect of
    propargite was an increase in maternal death at 105 mg/kg bw.

         Visceral examination did not reveal any dose-related effects
    other than small pups at 105 mg/kg bw. Again, in the positive controls
    there were significant increases in spina bifida and
    encephalomeningocele.

         Skeletal variations consisted primarily of incomplete
    ossification, missing sternebrae and retarded hyoid development, which
    occurred with greater frequency at 25 and 105 mg/kg bw than in the
    low-dose or vehicle control groups. Also noted at the high dose was
    incomplete closure of the skull. These skeletal variations are common
    in this species, are often considered an expression of maternal
    toxicity and their biological significance is not clearly understood
    at present. There were increased occurrences of these same variations
    in the positive control group, along with fused/split ribs,
    extranumery or rudimentary ribs and incomplete ossification of
    extremities.

         Propargite was not teratogenic in rats at any dose level
    administered, although there was evidence of maternal toxicity at 25
    and 105 mg/kg bw (Knickerbocker 1979).

    COMMENTS

         The ADI and supporting data were reviewed by the JMPR in 1977
    (FAO/WHO 1978). No additional data has been received that would alter
    those considerations.

    TOXICOLOGICAL EVALUATION

    Level Causing no Toxicological Effect

         Rat : 300 mg/kg in the diet, equivalent to 15 mg/kg bw.

         Dog : 900 mg/kg in the diet, equivalent to 22 mg/kg bw.

    Estimate of Acceptable Daily Intake for Man

         0 - 0.15 mg/kg bw.

    FURTHER WORK OR INFORMATION

    Desirable

    1.   Mutagenicity studies.

    2.   Observations in humans.

    REFERENCES

    Knickerbocker, M. Teratogenic evaluation of Omite technical in
    1979      Sprague-Dawley rats. Food and Drug Research Laboratories,
              Inc. Report submitted to the World Health Organization by
              Uniroyal Chemical Co. (Unpublished)

    PROPARGITE

    CHEMICAL STRUCTURE 1

    Explanation

         Propargite was evaluated in 1977, 1978, 1979 and 1980 (FAO/WHO
    1978b, 1979b, 1980b and 1981b)1 at which times several temporary
    maximum residue levels were either estimated or revised. The Joint
    Meeting has considered it desirable to have additional information
    on the metabolic fate of propargite in plants, especially
    characterization of substantial unidentified residues. Also desired
    was data from supervised trials in countries other than the U.S. and
    information on propargite residues on commodities in commerce.
    Additional studies on the metabolism of propargite in plants and
    residue data from countries other than the U.S. (including for tea and
    resulting from discussions at the 14th Session of the Codex Committee
    on Pesticides Residues) have been made available and are reviewed in
    this monograph addendum.

    RESIDUES IN FOOD AND THEIR EVALUATION

    USE PATTERN

         No information on nationally-approved agricultural practices has
    been provided to the Meeting for those commodities and for those
    countries from which additional residue data are available. The
    Meeting was informed that registration was discontinued in The
    Netherlands in 1976.

    RESIDUES RESULTING FROM SUPERVISED TRIALS

         Propargite residue data resulting from supervised trials in
    several countries other than the U.S. on several commodities are
    summarized in Table 1 (Uniroyal 1982). Since no nationally-approved
    agricultural practice information for these countries or on these
    commodities was available, previously submitted good agricultural
    practice information from other countries was taken into consideration
    to the extent possible in evaluating the data.

              

    1  See Annex 2 for FAO and WHO documentation, JMPR 1982 389-398

        Table 1.  Propargite Residues from Supervised Trials
                                                                                                                                           

                                                 Application                                            Residues (mg/kg)
                                                                                                                                         
    Crop                Country/
    (Variety)           Year           No.       Rate           Formulation    Interval
                                                 (kg a.i./ha)                  (day)                                   Untreated
                                                                                                                                           

    Apples              U.K. 1         2         0.75           57E
                                                 (0.07%)

    (Ross)              1979                                                   8              0.96                     <0.03
                                                                               16             0.80                     0.04
                                                                               23             0.56                     <0.02
    (Cox, O.P.)                                                                7              0.68                     <0.02
                                                                               10             0.52                     0.03
                                                                               18             0.33                     <0.02

    (Lascton                           1         0.86           57E            0              1.5-1.9                  <0.02-0.3
    Superb, Cox,                                 (0.17%)                                      (1.7 av.) 2              (0.1 av.) 2
    Bramley,            1981                     orchard                       7              1.1-1.9
    Egremont                                     sprayer                                      (1.5 av.) 2
    Russet)                                                                    14             0.6-1.7
                                                                                              (1.1 av.) 2
                                                                               21             0.51, 0.73

                        Poland

    (Mcintosh,                         1         0.75           30W            80             <0.05,                   <0.05, <0.05,
    Jonathan,                                    (0.075%)                                     <0.05,                   <0.05
    Lobo)                                        high                                         <0.05
                                                 volume
                                                 mist
                                                 blower
                                                                                                                                           

    Table 1.  (con't)
                                                                                                                                           

                                                 Application                                            Residues (mg/kg)
                                                                                                                                         
    Crop                Country/
    (Variety)           Year           No.       Rate           Formulation    Interval
                                                 (kg a.i./ha)                  (day)                                   Untreated
                                                                                                                                           

    (Mcintosh,                         1         0.9            30W            55             0.21, 0.09               <0.05, <0.05,
    Starking,                                    (0.06%)                                      0.39, 0.16               <0.05
    Bancroft,                                    high
    Idamont)                                     volume
                                                 mist
                                                 blower

    (Mcintosh,                         1         0.9            30W            55             <0.05,
    Starking,                                    (0.06%)                                      <0.05
    Boskop)                                                                                   <0.05

    (Grenadier)         U.K.           1         1.0            57E            7              1.1                      0.04, 0.26,
                        1980                     high                          14             0.89                     0.025
                                                 volume                        21             1
                                                 mist
                                                 blower

    (Cox)                              2         1.0            57E            4              2.4                      0.11, 0.02,
                                                 high                          7              2                        0.05
                                                 volume                        14             1.5
                                                 mist blower
                                                                                                                                           

    Table 1.  (con't)
                                                                                                                                           

                                                 Application                                            Residues (mg/kg)
                                                                                                                                         
    Crop                Country/
    (Variety)           Year           No.       Rate           Formulation    Interval
                                                 (kg a.i./ha)                  (day)                                   Untreated
                                                                                                                                           

    Black currants 1    U.K.           1         0.86           57E            0              5.1                      <0.03
    (Baldwin)                                    (0.043%)                      7              2.5                      <0.03
                        1981                     Knapsack                      14             1.2
                                                                               21             3.5,
                                                                                              2.3

                                                                               0              2                        <0.02
                                                                               7              0.94                     <0.02
                                                                               14             0.80
                                                                               21             0.27

    Hops, green         U.K.           1         0.86           57E            0              12                       <0.1
    (Wye)               1981                     (0.09%)                       7              1.2                      (3 samples)
                                                 mist blower                   14             1.5
                                                                               29             0.61 4
    (WVG)                                                                      0              3.9                      <0.1
                                                                               7              3.1                      (3 samples)
                                                                               14             3.1
                                                                               17             2.7 4

    Plums, fresh        U.K.           1         0.86           57E            0              0.29                     <0.01
    (Victoria)                                   (0.09%)                                      0.35
                                                 orchard                       7              0.53
                                                 sprayer                       14             0.35
                                                                               21             0.47
                                                                                                                                           

    Table 1.  (con't)
                                                                                                                                           

                                                 Application                                            Residues (mg/kg)
                                                                                                                                         
    Crop                Country/
    (Variety)           Year           No.       Rate           Formulation    Interval
                                                 (kg a.i./ha)                  (day)                                   Untreated
                                                                                                                                           

                        England
    (Czar)                                                                     0              0.67                     <0.01
                                                                               7              1.5
                                                                                              1.1
                                                                               14             0.58
    (Victory)                                                                  0              0.33
                                                                               7              0.28
                                                                               14             0.16
                                                                               21             0.13

    Tea                 India          1         0.75 5         57E            7              0.45-                    0.0 3
                        1976                                                                  0.66
                                                                                              (0.51 avg. of
                                                                                              6 samples)

                                                 1.5 5          57E            7              0.89
                                                                                              2.2
                                                                                              (1.3 avg. of
                                                                                              12 samples)

    Tomatoes 1          South Africa   2         0.56 8         57E            1 7            1.2                      0.014,
                                                 (0.07%)                       2 7            0.85                     <0.02,
                        1980                                                   4 7            1.6                      0.023
                                                                               6 6            0.83
                                                                               8 7            0.034
                                                                                              0.046
                                                                               16 7           0.29
                                                                                                                                           

    Table 1.  (con't)
                                                                                                                                           

                                                 Application                                            Residues (mg/kg)
                                                                                                                                         
    Crop                Country/
    (Variety)           Year           No.       Rate           Formulation    Interval
                                                 (kg a.i./ha)                  (day)                                   Untreated
                                                                                                                                           

                                       2         1.12           57E            1 7            3.6
                                                 (0.14%)                       2 7            2.0
                                                                               4 7            2.1
                                                                               6 6            2.3
                                                                               8 7            2.6
                                                                               16 7           0.97
                                                                                                                                           

    1  Residues corrected for analytical recoveries;
    2  Four samples;
    3  A 0.06 mg/kg limit of detection claimed;
    4  Commercially dried;
    5  Weather described as "wet";
    6  6 days after first treatment;
    7  Days after second treatment, the one day value is 7 days after first treatment;
    8  Late frulting stage at treatment.
             Except in the case of tea, in which Soxhlet extraction was used,
    and black currants, where the analytical method was not identified,
    the basic method (Devine and Sisken 1972) or modifications of it was
    used for developing data in Table 1. Recoveries were generally 80% or
    better.

    Apples

         Residues on several varieties of apples in the U.K. and Poland
    resulting from up to two applications at rates and preharvest
    intervals consistent with those on which the current 5 mg/kg limit is
    based are within that limit. The 5 mg/kg limit is confirmed.

    Black Currants

         Residues resulting from one application at 0.86 kg/ha in England
    range from a high level of 5.1 mg/kg on day of application to
    0.27 mg/kg at 21 days after last application. Although maximum
    residues are less than the 10 mg/kg limits for other small fruits, a
    limit could not be estimated in the absence of nationally approved
    agricultural information for currants. In addition to good
    agricultural practice information from U.K., additional residue data
    and good agricultural information from countries other than U.K. would
    be desirable for estimating maximum residue levels for black currants.
    The manufacturer has informed the Meeting that additional studies are
    in progress.

    Hops

         No information was available on nationally approved agricultural
    practices in the country from which additional residue data were
    available. With a single application at half the maximum rate, the two
    applications and 14-day preharvest interval used as a basis for the
    current 30 mg/kg limit, residues are well below that limit on both
    green and dried hops. However, there is a possibility that field
    incurred residues in dried hops, both in the new studies and those
    previously reviewed, were not quantitatively extracted by the standard
    analytical procedure (see discussion under "Tea"),

    Plums

         Although no information on nationally approved agricultural
    practice was available from the country in which the residue trials
    were conducted, residues from single applications of the EC
    formulation at application rates similar to those for other
    formulations used as a basis for the current 7 mg/kg limit on plums
    are well below that limit, even on day of application. The current
    limit is based on a 14-day interval from last application to harvest.

    Tea

         The current 5 mg/kg limit is based on application of a 57E
    formulation at a rate of 0.75 kg a.i./ha and a 7-day preharvest
    interval. Maximum residues in several samples based on this good
    agricultural practice (confirmed to this Meeting) were approximately
    4 mg/kg (FAO/WHO 1978b, 1979b). Based on data submitted to this
    Meeting, analytical methodology used in developing previously reviewed
    residue data does not efficiently extract residues from tea, dry or
    manufactured. The comparative extraction efficiencies of a Soxhlet
    extraction (see Methods of Analysis) and the standard procedure
    (Devine and Sisken 1972) are summarized in Table 2.

    Table 2.  Comparative Extraction of Propargite from Tea (mg/kg)
                                                                        

    Sample                      Extraction Technique
                        Standard Procedure       Soxhlet        Factor
                                                                        

    1                           0.2                1.0           5
    2                           0.3                0.9           3
    3 (sun dried)               0.6                1.5           2.5
    4 (sun dried)               0.57               1.2           2.1
    5 (sun dried)               0.52               1.2           2.3
    6 (manufactured)            1.0                2.0           2
    7 (manufactured)            1.3                2.0           1.5
    8 (manufactured)            1.0                2.2           2.2

                                                   Average       2.6
                                                                        

         Additional residue data (Table 1) in which Soxhlet extraction was
    utilized suggest that the current 5 mg/kg limit is adequate, even
    after using twice the recommended application rate. These data are
    consistent with much of the data previously reviewed. However, because
    residues from several samples previously reviewed (which were analysed
    by the standard procedure) were approximately 4 mg/kg, a 2-2.5 times
    increase in extraction efficiency would result in residues of about
    10 mg/kg.

         Other information provided to the Meeting shows that even with
    the standard procedure rehydration of sun-dried tea by soaking
    overnight with "2 times amount of water" can double the extraction
    efficiency.

    Tomatoes

         If the formulation and uses employed during the field trials
    indicated in Table 1 represent that country's nationally approved
    agricultural practices, the current 2 mg/kg limit for tomatoes is too
    low. A 5 mg/kg limit may be needed.

    FATE OF RESIDUES

    In Plants

         It is known that propargite is the largest component of the
    residue in plants and that the residue is primarily a surface one.
    There is evidence that it is not translocated to an appreciable extent
    and that losses are largely through volatilization. It has been
    hypothesized that propargyl alcohol and the propargite glycol ether
    (tertbutylphenoxycyclohexanol) are the primary metabolites, with
    further degradation to other moieties, but there has been little
    experimental evidence to confirm this. There has been some evidence
    for trace amounts of the glycol ether. Unidentified residues in plants
    have varied from 6-50% of total residues, with some not entirely
    conclusive evidence in peaches that no one component accounts for
    appreciably more than 10% of the total extractable residue. The Joint
    Meeting considered additional studies on the metabolic fate of
    propargite in plants desirable, especially for unidentified residues
    and the possibility of residues of the glycol ether. Additional
    studies have been provided in response to this request for further
    information.

         The metabolic fate of propargite in green beans, green bean
    callus tissue and maize callus tissue was investigated (Lengen 1982).
    Potted greenhouse grown green beans were sprayed or painted with
    14C-labelled propargite in a formulation with a specific activity of
    0.5 ÁCi/ÁM. The spray application was at a rate equivalent to 4.2 kg
    propargite/ha and beans were harvested 7 days later.

         Bean callus tissue was initiated from small pieces of immature
    pods, grown for two weeks, injected with the labelled formulation and
    harvested seven days after treatment. Similar experiments were
    conducted in maize callus (roots).

         Samples were extracted with methanol, some aliquots of which were
    partitioned further with chloroform. After concentration under a flow
    of nitrogen, using two solvent systems and X-ray film for location
    of bands, extracted residues were characterized by thin-layer
    chromatography. Mass spectrometry was used to confirm the identity
    of propargite. Unextracted residues were determined by combustion.
    Total residues in sprayed beans were 22 mg/kg at seven days. The
    distribution of propargite, the glycol ether and unidentified

    residues in bean and corn tissues are summarized in Table 3. The
    chromatographic behaviour, partitioning characteristics and
    distribution of residues extracted from beans are summarized in
    Table 4.

    Table 3  Distribution 1 of Residues in Propargite-Treated Beans 2
             and Bean and Maize Callus Tissue
                                                                        

                          Sprayed Bean      Bean Callus     Maize Callus
                                                                        

    Propargite               80.2              76.0                96.0

    Propargite                1.0               2.4                <1
     glycol ether

    Polar 3                   9.9              12.2                 1.1

    Unextracted               4.1               2.8                <1
                                                                        

    1  Percent of total residue;
    2  Total residues equivalent to 22 mg/kg;
    3  Resolved into a minimum of six components.

         Table 3 confirmed earlier studies, which show that propargite is
    the principal residue and that low residues of the glycol ether may be
    present. The level of unidentified residues in beans at 14% is within
    the range found in previous studies on plants, but less than the
    maximum. Propargite is shown to be less extensively metabolized in
    maize callus than in beans.

         Table 4 confirms that most of the residue is propargite which is
    organosoluble, and supports earlier findings suggesting the presence
    of glycol ether. If present, the ether comprises approximately 1% or
    less of the total in sprayed beans. Most of the aqueous partition
    fraction is polar material, although comparable levels of polar
    materials are also found in the chloroform fraction. Table 4 also
    shows that the 10% polar materials of Table 3 are composed of at least
    six unidentified components. No one of the six bands comprises more
    than 8.4% (band one) of the total (aqueous and organosoluble)
    extracted residue. Further investigation of band one with a second
    solvent system shows it to consist of eight unidentified and
    unquantified components in bean pods and six in maize callus. Three of
    the six in corn callus co-chromatograph with three found in the beans.

        Table 4.  Distrlhution of 14C-Labelled Components on TLC of 14C-Omite Treated Blue Lake Bean Tissue 1
                                                                                                                             

                                                            Percent of metabolites in the chloroform fraction 2
                                                                                                                             
                                               Sprayed pods                  Painted pods                      Callus
                                                                                                                             

    Band                                    % in           % of           % in           % of           % in           % of
    No.                 Rf                  Fraction       Total          Fraction       Total          Fraction       Total
                                                                                                                             

    1                   0.0-0.03              3.2          (3.0)             3.2         (3.1)            5.4          (4.9)

    2                   0.03-0.11             0.7          (0.6)             0.9         (0.9)            1.0          (0.9)

    3                   0.11-0.19 3           0.9          (0.8)             1.0         (1.0)            2.5          (2.3)

    4                   0.19-0.27             0.9          (0.8)             0.9         (0.9)            1.2          (1.1)

    5                   0.27-0.37             5.1          (4.7)             4.6         (4.4)            6.0          (5.5)

    6(Omite)            0.37-0.36            87.3         (81.0)            83.9        (80.7)           81.9         (74.9)

    7                   0.46-1.0              1.9          (1.8)             5.4         (5.2)            1.8          (1.6)
                                                                                                                             

    Table 4.  (con't)
                                                                                                                             

                                                            Percent of metabolites in the chloroform fraction 2
                                                                                                                             
                                               Sprayed pods                  Painted pods                      Callus
                                                                                                                             

    Band                                    % in           % of           % in           % of           % in           % of
    No.                 Rf                  Fraction       Total          Fraction       Total          Fraction       Total
                                                                                                                             

                                                            Percent of metabolites in the aqueous fraction 2

    1                   0.0-0.03             75.8          (5.4)            72.1         (2.7)           87.2          (7.4)

    2,3,4,5             0.03-0.21             8.0          (0.6)             8.3         (0.3)            5.1          (0.4)

    6 (Omite)           0.21-0.29             9.6          (0.7)            13.0         (0.5)            3.6          (0.3)

    7                   0.29-1.0              6.6          (0.5)             6.6         (0.3)            4.1          (0.3)
                                                                                                                             

    1  TLC = double or single development in cyclohexane-ethyl acetate (9:1); interval is 7 days.

    2  The Rfs and percentages are an average of two plates.

    3  Co-chromatography with glycol ether.
        METHODS OF RESIDUE ANALYSIS

         The analytical method for Soxhlet extraction of propargite from
    tea was provided to the Meeting and was used to develop the data in
    Table 1. Twenty-five grams of tea in a Soxhlet thimble underwent
    extraction in a unit containing 300 ml hexane for 16 hours. A 10 g
    aliquot was eluted from a 15 cm florosil (activated at 130░C) column
    with 2% acetone in hexane after an initial elution with 100 ml of
    benzene, which was discarded. After concentration to 2 ml, GLC
    analysis was conducted, using a sulphur specific flame photometric
    detector. The limit of detection was said to be approximately
    0.05 mg/kg, although of two untreated samples analysed when the
    standard procedure was compared to Soxhlet extraction, residues were
    listed as 0.0 and 1.96 mg/kg. Residues in two untreated samples during
    the field trials were listed as 0.0 mg/kg.

         The analytical method was validated at 0.5 to 2 mg/kg
    fortification levels with recoveries >81%. It would appear that
    analytical methods of choice for tea should include a Soxhlet
    extraction step. The standard analytical method, while not preferred
    for tea, can be improved for tea by a rehydration step if it is used.

    APPRAISAL

         The Meeting was provided with additional studies characterizing
    propargite residues in plants and results from some additional residue
    studies in countries other than the U.S. Both items of information had
    been considered desirable by the Joint Meeting.

         No information was available on nationally approved uses in the
    countries from which residue data were available. Based on good
    agricultural practices, the current limit for apples, hops and plums
    could be confirmed. However, new information on the efficiency of
    extraction of propargite residues from dried commodities leaves some
    doubt as to the adequacy of the current limit for hops. Additional
    residue data from field incurred residues in dried hops resulting from
    good agricultural practices expected to give maximum residues is
    desirable, using an analytical method employing a Soxhlet extraction
    step. An alternative, but less desirable, analytical method could be
    the standard procedure modified width a rehydration step.

         The available data and lack of information on nationally approved
    agricultural practices does not permit estimation of a limit on black
    currants at this time.

         New information on the extraction efficiency of the standard
    analytical procedure for propargite in dried tea supports an increase
    in that limit and suggests that analyses of all dried commodities for
    propargite should use an analytical method employing a Soxhlet type

    extraction step. The standard analytical method of Levine and Sisken
    modified with a rehydration step appears to be an alternative but less
    desirable method for dried commodities.

         In the case of tomatoes, additional data suggest that the current
    2 mg/kg limit may be too low. However, in the absence of information
    on nationally approved agricultural practices in countries from which
    data have been provided, there is no basis for revising the current
    limit.

         Recently conducted studies on the metabolic fate of propargite in
    beans confirm that propargite is the major single residue and support
    earlier studies suggesting the presence of low levels of propargite
    glycol ether (1% as compared to 7% in an earlier study on dried bean
    pods). Qualitatively, unidentified moieties are shown to consist
    largely of polar materials, which is similar to findings in studies
    previously reviewed by the Joint Meeting. Quantitatively, and under
    different experimental conditions (including some substantially longer
    preharvest intervals), some of the earlier studies have shown
    unidentified residues to constitute over half of the total residue.

         In those earlier metabolism studies in dry bean pods (FAO/WHO
    1981b) residues were extracted with methanol/acetone, whereas in field
    trials on dry beans (FAO/WHO 1978b) residues were low but the standard
    extraction procedure utilizes hexane/isopropanol, which may not have
    extracted all of the polar materials. In the studies submitted to this
    Meeting, unidentified residues constituted approximately 20% of the
    total and extraction was with methanol.

         While the new studies do give further confirmation of earlier
    findings, no new information is available on the actual identity of
    metabolites/degradation products that would allow confirmation of the
    postulated metabolic pathway of propargite in plants. The additional
    study indicating that no one component of the metabolites constitutes
    more than 10% of the total residue in beans does give some
    reassurance. If this same statement could be made under those
    conditions resulting in unidentified residues at over 50% of total
    residue, even greater assurance would be given. Under these
    circumstances, the actual identity of the major unidentified residues
    is still desirable.

    RECOMMENDATIONS

         In the case of tea, the Meeting concluded that the existing
    temporary limit should be revised as indicated. For other commodities
    data either confirmed existing limits or were insufficient to support
    revision of existing limits of estimation of new levels.

    Commodity                Estimated Maximum Residue Level (mg/kg)
                                                                        

    Tea                      10 (5)

    FURTHER WORK OR INFORMATION

    Desirable

    1.   Information on nationally approved good agricultural practices,
         especially from those countries in which field trials have been
         conducted and for which residue data have been provided to the
         1982 Joint Meeting, or which may be provided to a future Joint
         Meeting.

    2.   Residue data from field incurred residues in dried hops resulting
         from good agricultural practices expected to result in maximum
         residues and analysed by a validated analytical method utilizing
         a Soxhlet type extraction step.

    3.   Actual identification of the major propargite plant metabolite
         degradation products.

    4.   Information on the occurrence of residues in commodities in
         commerce.

    REFERENCES

    Devine, J.M. and Sisken, H.R. Use of flame photometric detector
    1972      for determining residues of Omite [2-(p tert-
              butylphenoxy)cyclohexy) propargyl sulfite] Journal of
              Agricultural Food Chem. 20: 59-61.

    Lengen, M. Propargite metabolism in beans and corn, Project No. 8107,
    1982      June 1982. Studies conducted by Galye H. Davidonis and Ralph
              O. Mumma, Pennsylvania State University 9 June 1982.
              (Unpublished)

    Uniroyal. Residue data submitted to the 1982 Joint Meeting by Uniroyal
    1982      Chemical, Division of Uniroyal, Inc,, Agricultural Chemicals
              Research and Development, 74 Amity Road, Bethany, CT 06525.
              Determination of Omite residues in apples, J. 2774,
              DM79/2381D, J2774, DM79/237D, 20 May 1980; 217/4; M81/19B,
              C, D and E, M81/20B, C, D and E; M81/21B, C, D and E;
              M81/22B, C, D and E, 28 October, 1981; J3225, M80/250,
              M80/251, 28 November, 1980. Residues of propargite in apples
              by Dr. Boleslaw Salmonowicz, March 1982. Determination of
              Omite residues in Currants, 217/1; M81/25, 217/1, M81/26,
              28 October 1981; Determination of Omite residues in Hops,
              21713; M81/23, 21713, M81/24, July 1982; Determination of
              Omite residues in plums, 217/2, 217/2, M81/27, 217/2,
              M81/28, 28 October 1981.

              Omite residues in tomatoes, J2911, 8 May 1980.
              Data submitted to the 1982 JMPR and initially developed and
              submitted 19 January 1977 to the U.S. Environmental
              Protection Agency in support of U.S. pesticide tolerance
              petition FAP6H5100. (Unpublished)


    See Also:
       Toxicological Abbreviations
       Propargite (Pesticide residues in food: 1977 evaluations)
       Propargite (Pesticide residues in food: 1978 evaluations)
       Propargite (Pesticide residues in food: 1979 evaluations)
       Propargite (Pesticide residues in food: 1980 evaluations)
       Propargite (JMPR Evaluations 1999 Part II Toxicological)