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    PESTICIDE RESIDUES IN FOOD - 1984


    Sponsored jointly by FAO and WHO






    EVALUATIONS 1984




    The monographs



    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, 24 September - 3 October 1984

    Food and Agriculture Organization of the United Nations
    Rome 1985

    PROPINEB

    Explanation

         Propineb was evaluated by the 1977 JMPR (FAO/WHO, 1979). 1/ A
    temporary ADI and temporary MRLs were estimated by that meeting. MRLs
    were identical to those of the ethylene-bisdithiocarbamates.

         New information was received by the 1984 JMPR on current GAP and
    on residues from supervised trials in accordance with such practices.

    RESIDUES IN FOOD AND THEIR EVALUATION

    USE PATTERN

         Propineb, a propylene-bisdithiocarbamate fungicide, is used, with
    very few exceptions, similarly to the ethylene-bisdithiocarbamates. It
    is used as a protection treatment on several crops for the control of
    various fungi, especially Oomycetes such as Phytophthora spp,
    Pythium spp and other pathogens belonging to the Ascomycetes,
    Basidiomycetes and Fungi imperfecti.

         The current use pattern is summarized in Table 1. The main uses
    are preventive control of fungal diseases on grapes, potatoes (against
    Phytophthora), apples, tomatoes and tobacco.

    RESIDUES RESULTING FROM SUPERVISED TRIALS

         Information on residues resulting from supervised trials, mainly
    from the Federal Republic of Germany, included data from trials on
    apples, pears, sour cherries, peaches, plums, grapes, celeriac,
    potatoes and tomatoes. Information was also received on residues in
    processed commodities derived from some of the crops mentioned, such
    as juice from apples, cherries and tomatoes, must and wine from
    grapes, apple sauce, jam from cherries, mash from pears and plums and
    tomato ketchup. The data are summarized in Table 2.

    Apples

         Propineb residues expressed as CS2, ranged from 0.7-6.0 mg/kg on
    the day of treatment and from about 0.36-1.5 mg/kg after 14 days. The
    propylenethiourea (PTU) levels at the same sampling dates were
    0.2-0.5 mg/kg and 0.03-0.11 mg/kg respectively. The PTU residues in
    cold-pressed apple juice were slightly lower than in juice pasteurized
    at 60-70C. In the latter, the maximum PTU residue was 0.06 mg/kg. The
    PTU residues in apple sauce cooked for a short period at ca. 125C
    ranged from <0.01 to 0.05 mg/kg.


              

    1/  See Annex 2 for FAO and WHO documentation


        TABLE 1.  Use Pattern of Propineb

                                                                                              
                             Dosage rate         Applications        Preharvest interval
                             (kg a.i./ha)        (no.)               (days)
                                                                                              

    Africa

       Grapes                0.35-21             4-10                14
       Potatoes              0.7-2.1             4-8                 3
       Tomatoes              0.7-4.2             4-8                 3
       Peanuts               1.4-2.1             2-4                 21

    Asia

       Potatoes              1.05-1.4            8-20 1
       Tomatoes              1.05-1.75           8-20 1              7
       Beans                 1.05-2.1            12                  7
       Cucurbits             1.2                                     2

    Australia and New Zealand

       Potatoes              1.05-2.8            4-8                 7
       Tomatoes              0.84-1.75           4-8                 7-10

    Europe (except Mediterranean area)

       Pome fruit            1.4-2.8             8-12                7-28
       Stone fruit           1.4-2.8             2-3                 7-28
       Berries and           2.1-2.8             2-3                 14
        other small fruit
       Grapes                1.75-2.8            4-10                21-56
       Cucumbers             0.84-1.4            2-4                 3-7
       Celery                0.84-1.0            2-3                 7-28
       Potatoes              1.05-2.8            4-8                 7-10
       Tomatoes              0.84-1.7            4                   3-7
       Hops                  1.5-4.2             10-14               14-35
       Tobacco               2.1-2.8             10-16               7


    Europe (Mediterranean area)

       Pome fruit            1.4-2.8             8-12                7-10
       Stone fruit           2.0                 2-3                 28
       Citrus fruit          2.1-4.2             3-6                 14
       Grapes                1.75-2.8            3-10                21-28
       Cucurbits             0.84-1.4            2-4                 4-15
       Potatoes              1.05-2.8            4-8                 7-28
       Tomatoes              0.84-1.75           4-8                 4-15
       Tobacco               2.1-2.8             10-16               7
                                                                                              

    TABLE 1.  (continued)

                                                                                              
                             Dosage rate         Applications        Preharvest interval
                             (kg a.i./ha)        (no.)               (days)
                                                                                              

    Near East

       Potatoes              1.4-2.5                                 3
       Tomatoes              1.4-2.9                                 3
       Citrus fruit          2.4
       Cucumbers             1.4                                     3
       Grapes                0.7-2.1

    South America

       Tobacco               1.75-2.1            8-10                7
                                                                                              

    1  In areas with heavy rainfall
    

        TABLE 2.  Propineb Residues in Various Crops from Supervised Trials, Federal Republic of Germany

                                                                                                             
    Crop          Year      Application1                             Residues
                                              Pre-                                                           
                            No.    Rate       harvest       Propineb as CS2               PTU
                                   (kg a.i.   interval                                                       
                                   /ha)       (days)      average    range        average      range
                                                                                                             

    APPLE 2       1978      12     2.8           0         4.1       3.1-6.0       0.23        0.2-0.26
                                                 4         3.4       2.8-3.9       0.17        0.16-0.17
                                                 7         3.3       1.9-4.1       0.22        0.21-0.23
                                                10         2.5       1.1-4.2       0.13        0.11-0.15
                                                13         0.84      0.79-0.89     0.085       0.08-0.09

                            11     2.8           0         5.1       4.2-5.9       0.45        0.40-0.49
                                                 4         3.6       3.3-3.8       0.30        0.30
                                                 7         2.2       1.6-2.6       0.28        0.27-0.29
                                                10         1.2       1.1-1.2       0.15        0.11-0.2
                                                13         1.2       0.95-1.5      0.10        0.09-0.11

    fruit                   12     2.8           0         1.8       1.2-2.4       0.07
                                                 5         1.5       0.79-2.7      0.09
                                                 7         1.8       1.7-1.9       0.05
                                                10         0.84      0.84          0.05
                                                14         0.81      0.79-0.84     0.05
    juice                                       10        <0.1                    <0.01
    sauce                                       10        <0.1                     0.03

    fruit         1980      12     2.8          10         0.89      0.73-1.05     0.079
    juice, cold                                 10         0.34      0.33-0.44     0.015
    juice, 65C                                 10        <0.05                    0.046
    sauce                                       10        <0.05                    0.017

    fruit         1978      12     2.8           0         0.89      0.63-1.15     0.08
                                                 4         0.89                    0.07
                                                 7         0.84                    0.11
                                                10         0.47                    0.05
                                                14         0.36                    0.04
                                                                                                             

    TABLE 2.  (continued)

                                                                                                             
    Crop          Year      Application1                             Residues
                                              Pre-                                                           
                            No.    Rate       harvest       Propineb as CS2               PTU
                                   (kg a.i.   interval                                                       
                                   /ha)       (days)      average    range        average      range
                                                                                                             

    juice, cold                                 10         0.19      0.17-0.21    <0.01
    juice, 65C                                 10         0.28      0.26-0.29    <0.01
    sauce, 125C                                10        <0.1      <0.1           0.05

    fruit         1980      12     1.57         10         0.16      0.14-0.18     0.01        0.009-0.011
    juice, cold                                 10        <0.1                    <0.01
    juice, 65                                  10        <0.1                    <0.01
    sauce                                       10        <0.1                    <0.01

    fruit                   12     1.57         10         2.4                     0.058       0.056-0.060
    juice, cold                                 10         1.25      1.2-1.3       0.017       0.015-0.019
    juice, 65                                  10        <0.05                    0.052       0.048-0.056
    sauce                                       10         0.09      0.09-0.095    0.052       0.050-0.054

    fruit         1982      10     2.1          21         0.96      0.92-0.99     0.027       0.026-0.027
                                                28         0.80      0.72-0.88     0.026       0.021-0.03
    juice, 65                                  21        <0.05                    0.025       0.023-0.027
    sauce                                       21        <0.05                    0.021       0.021-0.021

    PEAR

    fruit         1982      10     2.1          21         0.52      0.52-0.52     0.057       0.050-0.063
                                                28         0.55      0.52-0.58     0.053       0.050-0.055
    sauce, 125                                 21        <0.05                   <0.01

    fruit                   10     2.1          17        <0.05                   <0.01
    sauce, 120                                 17        <0.05                   <0.01

                                                                                                             

    TABLE 2.  (continued)

                                                                                                             
    Crop          Year      Application1                             Residues
                                              Pre-                                                           
                            No.    Rate       harvest       Propineb as CS2               PTU
                                   (kg a.i.   interval                                                       
                                   /ha)       (days)      average    range        average      range
                                                                                                             

    CHERRY, SOUR 3

    fruit         1982      3      1.58          0         5.22      4.88-5.55     0.11        0.10-0.11
                                                14         0.77      0.71-0.83     0.051       0.05-0.052
                                                21         0.26      0.23-0.29     0.034       0.032-0.035
                                                28         0.15      0.13-0.17     0.017       0.010-0.024
                                                35         0.05      0.053-0.053  <0.01
    juice                                       28         0.09      0.076-0.11    0.013       0.012-0.013
    jam                                         28         0.05      0.049-0.056   0.017       0.017-0.017

    fruit         1979      3      2.1           0         3.4       2.3-4.7       0.35        0.31-0.39
                                                 7         0.87      0.83-0.91     0.14        0.13-0.14
                                                14         0.56      0.55-0.56     0.13        0.10-0.15
                                                21         0.50      0.46-0.53     0.04        0.03-0.05
                                                28         0.23      0.21-0.25     0.02        0.02
    juice                                       21         0.06     <0.05-0.08     0.05        0.05-0.05
    jam                                         21         0.09      0.089-0.094   0.02        0.02-0.02

    fruit                   3      1.58          0         3.2       3.1-3.2       0.35        0.34-0.35
                                                 7         2.1       1.9-2.2       0.31        0.26-0.35
                                                14         0.23      0.21-0.24     0.03        0.03-0.033
                                                21         0.21      0.18-0.23     0.02        0.018-0.022
                                                28        <0.05                    0.02        0.018-0.022
    juice                                       21        <0.05                    0.12        0.11-0.12
    jam                                         21         0.12      0.10-0.14     0.067       0.056-0.078
                                                                                                             

    TABLE 2.  (continued)

                                                                                                             
    Crop          Year      Application1                             Residues
                                              Pre-                                                           
                            No.    Rate       harvest       Propineb as CS2               PTU
                                   (kg a.i.   interval                                                       
                                   /ha)       (days)      average    range        average      range
                                                                                                             

    fruit                   3      1.58          0         5.8       2.5-9.3       0.43        0.39-0.46
                                                 7         1.9       1.7-2.3       0.33        0.31-0.34
                                                14         0.56      0.54-0.57     0.065       0.062-0.067
                                                21         0.41      0.33-0.49     0.093       0.092-0.094
                                                28        <0.1                     0.023       0.022-0.024
    juice                                       21        <0.1                     0.021       0.019-0.022
    jam                                         21        <0.1                     0.020       0.02-0.02

    PEACH

    fruit         1980      3      1.58          0         5.46      5.43-5.48
                                                 7         4.15      4.07-4.22
                                                14         2.38      2.30-2.41
                                                21         2.35      2.30-2.40     0.025       0.021-0.029
                                                28         0.95      0.9-1.0

    PLUMS 4

    fruit         1979      3      2.1           0         1.5       1.4-1.5       0.08        0.07-0.09
                                                 7         0.72      0.68-0.76     0.05        0.05-0.05
                                                14         0.40      0.38-0.42     0.04        0.03-0.04
                                                21         0.31      0.30-0.32     0.02        0.02-0.03
                                                28         0.25      0.24-0.25     0.04        0.04
    pulp                                        21        <0.1                     0.18        0.17-0.18

    fruit                   3      1.58          0         1.0       0.89-1.11     0.03        0.03-0.04
                                                 7         0.39      0.38-0.40     0.03        0.03-0.03
                                                14         0.44      0.42-0.46     0.04        0.03-0.04
                                                21         0.12      0.1-0.14      0.01        0.12
                                                28        <0.05                    0.01        0.009-0.01
                                                                                                             

    TABLE 2.  (continued)

                                                                                                             
    Crop          Year      Application1                             Residues
                                              Pre-                                                           
                            No.    Rate       harvest       Propineb as CS2               PTU
                                   (kg a.i.   interval                                                       
                                   /ha)       (days)      average    range        average      range
                                                                                                             

    pulp                                        21        <0.1                     0.21        0.17-0.24

    fruit         1982      3      1.58          0         1.5       1.5-1.5       0.03        0.02-0.03
                                                14         0.8       0.7-0.8       0.04        0.03-0.04
                                                21         0.6       0.5-0.6       0.04        0.03-0.04
                                                28         0.2       0.2-0.2      <0.01       <0.01-<0.01
                                                35         0.2       0.2-0.2       0.02        0.01-0.02
    pulp                                        28        <0.05                    0.07        0.05-0.08

    fruit                   3      1.58          0         1.2       1.1-1.2       0.02        0.02-0.02
                                                14         0.2       0.2-0.2       0.02        0.02-0.02
                                                21         0.4       0.3-0.4       0.02        0.02-0.02
                                                28        <0.05     <0.05-<0.05    0.01       <0.01-0.01
                                                35         0.3       0.3-0.3       0.02        0.02-0.02
    pulp                                        28        <0.05     <0.05          0.05        0.04-0.06

    fruit                   3      1.58          0         1.2       1.1-1.2       0.04        0.03-0.05
                                                14         0.1       0.1-0.1      <0.01       <0.01-<0.01
                                                21         0.4       0.3-0.4       0.02        0.02-0.02
                                                28         0.06      0.05-0.06    <0.01       <0.01
                                                35        <0.05                   <0.01       <0.01
    pulp                                        28        <0.05                    0.05        0.04-0.05

    fruit         1980      3      1.58         21         0.36      0.35-0.37    <0.01
    pulp                                        21        <0.05                    0.04        0.04-0.04

    fruit                   3      1.58         21         0.34      0.33-0.35    <0.01
    pulp                                        21        <0.05                   <0.05        0.049-0.051

                                                                                                             

    TABLE 2.  (continued)

                                                                                                             
    Crop          Year      Application1                             Residues
                                              Pre-                                                           
                            No.    Rate       harvest       Propineb as CS2               PTU
                                   (kg a.i.   interval                                                       
                                   /ha)       (days)      average    range        average      range
                                                                                                             

    GRAPES, WHITE 5

    fruit         1979      8      2.8          79         1.4       1.24-1.93     0.085       0.076-0.093
    must                                        79         0.77      0.69-0.84     0.022       0.017-0.026
    wine (fust)                                            0.07      0.04-0.09     0.12        0.11-0.12

    fruit                   8      2.8          63         0.79      0.66-0.95     0.055       0.044-0.066
    must                                        63         0.26      0.16-0.29     0.052       0.049-0.055
    wine (bottled)                                        <0.05     <0.05          0.019       0.017-0.021

    fruit         1980      8      1.4-2.8      42         2.6       2.5-2.6       0.17        0.16-0.17
    must                                        42         0.20      0.17-0.22     0.04        0.042-0.043
    wine                                                  <0.05                    0.05        0.052-0.056

    fruit         1981      8      1.4-2.8      69         0.75      0.71-0.79     0.048       0.044-0.052
    must                                        69         0.41      0.40-0.42     0.071       0.067-0.074
    wine                                       179         0.05      0.05-0.05     0.10        0.09-0.11

    fruit         1982      8      2.8          73         1.7       1.6-2.0       0.1
    must                                        73         1.15      0.76-1.45     0.07        0.066-0.073
    wine (bottled)                                        <0.05                    0.007       0.086-0.087

    GRAPES, RED 6

    fruit         1982      6      1.4          35         0.5       0.4-0.6       0.03        0.03-0.03
    must                                        35         0.1       0.1-0.1       0.2         0.2-0.2
    wine                                       162         0.1       0.1-0.1       0.1         0.1-0.1
                                                                                                             

    TABLE 2.  (continued)

                                                                                                             
    Crop          Year      Application1                             Residues
                                              Pre-                                                           
                            No.    Rate       harvest       Propineb as CS2               PTU
                                   (kg a.i.   interval                                                       
                                   /ha)       (days)      average    range        average      range
                                                                                                             

    fruit                   5      1.4-2.8      49         0.2       0.2-0.2       0.08        0.08-0.08
    must                                        49         0.05     <0.05-0.08     0.02        0.02-0.02
    wine                                       176         0.05      0.04-0.06     0.07        0.06-0.1

    fruit         6         1.4-2.8             42         0.07      0.06-0.07     0.02        0.02-0.02
    must                                        42         0.08      0.06-0.1      0.04        0.04-0.05
    wine                                       162        <0.05                    0.05        0.04-0.06

    CELERIAC

    roots         1978      3      1.05          0        <0.05                   <0.05
                                                14        <0.05                   <0.05
                                                21        <0.05                   <0.05
                                                28        <0.05                   <0.05

    leaves                                       0         8.9       7.4-11       <0.05
                                                14         0.47      0.42-0.53    <0.05
                                                21         0.14                   <0.05
                                                28        <0.05                   <0.05

    roots                   3      1.05          0        <0.1                    <0.05
                                                14        <0.1                    <0.05
                                                21        <0.1                    <0.05
                                                28        <0.1                    <0.05

    leaves                                       0        13     12-14            <0.05
                                                14         1.4                    <0.05
                                                21         0.63      0.58-0.68    <0.05
                                                28         0.41      0.32-0.49    <0.05
                                                35         0.28      0.27-0.30    <0.05
                                                                                                             

    TABLE 2.  (continued)

                                                                                                             
    Crop          Year      Application1                             Residues
                                              Pre-                                                           
                            No.    Rate       harvest       Propineb as CS2               PTU
                                   (kg a.i.   interval                                                       
                                   /ha)       (days)      average    range        average      range
                                                                                                             

    POTATOES

                  1979      8      1.3           0         0.12                   <0.01
                                                 1        <0.04                   <0.01
                                                 4        <0.04                   <0.01
                                                 7        <0.04                   <0.01

                            8      1.3           0        <0.04                   <0.01
                                                 1        <0.04                   <0.01
                                                 4        <0.04                   <0.01
                                                 7        <0.04                   <0.01

    TOMATOES

    fruit         1978      6      1.26-1.68     0         1.8       1.4-2.2       0.1         0.05-0.14
                                                 1         1.0       0.57-1.55     0.08
                                                 4                                 0.13        0.07-0.19
                                                 7         0.34      0.25-0.55    <0.01
                                                10         0.36      0.34-0.37     0.03
    juice                                        4         0.21      0.20-0.21     0.03
    ketchup                                      4        <0.1                     0.05        0.04-0.05

                            6      1.26-1.68     0         1.2       1.0-1.4       0.07        0.06-0.08
                                                 1         0.63      0.4-0.85      0.09        0.08-0.09
                                                 4                                 0.14        0.11-0.16
                                                 7         0.39      0.37-0.40     0.08        0.07-0.09
                                                10         0.39      0.31-0.46     0.02        0.02-0.02
    juice                                        4         0.28      0.26-0.29     0.03        0.02-0.03
    ketchup                                      4         0.14      0.11-0.16     0.03        0.03-0.03
                                                                                                             

    TABLE 2.  (continued)

                                                                                                             
    Crop          Year      Application1                             Residues
                                              Pre-                                                           
                            No.    Rate       harvest       Propineb as CS2               PTU
                                   (kg a.i.   interval                                                       
                                   /ha)       (days)      average    range        average      range
                                                                                                             

                  1979      6      0.8-1.6       0         0.86      0.84-0.87     0.043       0.039-0.047
                                                 1         0.79      0.61-0.97     0.028       0.027-0.029
                                                 4         0.67      0.45-0.89     0.019       0.016-0.022
                                                 7         0.50      0.39-0.61     0.052       0.044-0.06
                                                10         0.23      0.21-0.24     0.055       0.051-0.058
    juice                                        4         0.41      0.35-0.51     0.12        0.12-0.13
    ketchup                                      4        <0.05                    0.046       0.025-0.087

    fruit         1980      6      1.26-1.68     4         0.39      0.38-0.39     0.012       0.012-0.013
    juice                                        4         0.24      0.22-0.26     0.017       0.016-0.018
    ketchup                                      4        <0.05                    0.044       0.039-0.048

    fruit         1980      6      1.26-1.68     4         0.075     0.07-0.08     0.011       0.01-0.011
    juice                                        4         0.23      0.20-0.26     0.018       0.016-0.02
    ketchup                                      4        <0.05                    0.038       0.036-0.039

    fruit         1980      6      0.84-1.68     5         0.75                    0.024       0.022-0.025
    ketchup                                      5         0.07      0.06-0.07     0.079       0.076-0.081

    fruit         1978      6      0.84-1.68     0         0.54      0.46-0.61     0.03
                                                 1         0.43      0.38-0.48     0.05
                                                 4         0.38      0.36-0.39     0.04
                                                 7         0.32      0.30-0.34     0.02

    fruit         1978      6      0.84-1.68     0         0.66      0.47-0.84     0.04
                                                 1         0.22      0.16-0.28     0.05
                                                 4         0.30      0.28-0.32
                                                 7         0.08      0.07-0.1      0.02
                                                                                                             

    TABLE 2.  (continued)


    1  A 70% W.P. formulation was used in all trials.
    2  Two additional trials on aDDles gave similar results.
    3  Four additional trials on sour cherries, three in 1980 and one in 1982, gave similar results.
    4  Three additional trials on plums gave similar results.
    5  Sixteen additional trials on white grades, three in 1979, six in 1980, three in 1981 and four in 1982, gave similar results.
    6  Four additional trials on red grapes in 1982 gave similar or lower residues.

    Source: Bayer, 1978-1983
    
    Pears

         Propineb residues expressed as CS2 ranged from about 2.3 to
    9.3 mg/kg on the day of treatment and from 0.2 to 6.8 mg/kg after 14
    days. Maximum levels of PTU at the latter sampling date were about
    0.1 mg/kg. PTU residues in pear mash were <0.01 mg/kg.

    Cherries

         Initial residues of propineb as CS2 were 2.3-5.6 mg/kg, and
    after 14 days the highest CS2 level found was 0.9 mg/kg. PTU levels
    14 days after the last application ranged from 0.03 to 0.15 mg/kg.
    Residues in the juice from cherries harvested 21-28 days after the
    last application were of the order of 0.01-0.12 mg/kg and jam made
    from cherries picked at the same dates contained 0.02-0.08 mg/kg.

    Peaches

         Propineb levels, expressed as CS2 decreased from about 5.4 mg/kg
    initially to 2.5 mg/kg 14 days later and to about 1 mg/kg after 28
    days (the recommended preharvest interval in several countries).

    Plums

         Propineb levels, as CS2, of about 0.9-1.5 mg/kg on the day of
    treatment decreased to 0.4-0.8 mg/kg after 14 days and to about
    0.1-0.25 mg/kg 28 days after the last application. The levels of PTU
    were in the range <0.01-0.04 mg/kg both 14 and 28 days after the last
    application. PTU levels in the processed pulp were somewhat higher
    than in the fresh fruit sampled at the same time (21-28 days after
    harvest).

    Grapes

         White grapes treated 8-11 times during the growing season showed
    propineb residues, after the generally recommended preharvest
    intervals of 42-60 days, ranging from 0.6 to 2.6 mg/kg. Residues in
    red grapes, all from trials carried out in the same year, were lower.
    After observing preharvest intervals of 35-49 days, the highest
    residue found was 0.1 mg/kg. The residue in must was about 25-50
    percent of the residue in the grapes from which the must was made.
    This indicates that the propineb residues mainly occur on the skin,
    with a substantial loss of the residue during the preparation of must.
    Another loss of the parent compound occurs during further processing
    from must to wine. The PTU residue showed a tendency to increase
    slightly. The maximum levels of propineb as CS2 and of PTU found in
    wine in a series of trials carried out according to GAP were 0.1 mg/kg
    and 0.12 mg/kg respectively.

    Celeriac

         The roots of celeriac showed no measurable residue of propineb,
    as CS2, or of PTU. After a preharvest interval of 14 days, the
    propineb levels in leaves were 0.5-1.4 mg/kg and after 28 days, the
    maximum residue found was 0.5 mg/kg. PTU could not be detected in the
    leaves at any of the sampling dates.

    Potatoes

         In the potato tubers, propineb as CS2 and PTU were undetectable.
    The limits of detection were 0.04 mg/kg and 0.01 mg/kg respectively.

    Tomatoes

         Residues of propineb expressed as CS2 in tomatoes sampled 4-7
    days after the last application (the generally recommended preharvest
    interval was about 0.25-0.9 mg/kg. The maximum levels of PTU at the
    same sampling dates were about 0.1-0.2 mg/kg.

    FATE OF RESIDUES

    In Plants

         Vogeler (1980) summarized the data on metabolism in plants and
    processed commodities, such as wine, which were available to the 1977
    JMPR together with more recent information.

         The new studies identified the main metabolite, previously
    unknown, as 4-methylimidazoline (Figure 1, VI) by comparing its mass
    spectrum with that of the authentic compound. The structure was also
    confirmed by its proton resonance spectrum in CD3COOD.

         In the light of the new studies, the proposed structures of some
    of the metabolites had to be corrected. The corrected structures and
    the most probable metabolic pathway of propineb on and in plants; are
    shown in Figure 1.

    In Processing

         Dreze & Vogeler (1979) evaluated the fate of 14C-propineb on
    apples and in the preparation of apple sauce. The compound was
    labelled in the C-1 position of the propylenediamine group; it was
    sprayed first one time and in another experiment three times, and
    residues on apples were analysed on the day of treatment and 14 days
    after the (last) application. Apples were washed with methanol and
    EDTA solution, then extracted with methanol. The following metabolites
    were identified by TLC in the surface wash and in the methanol extract
    and determined semi-quantitatively.

    FIGURE 1

                                                                        

    Compound                                                 Total
                                                          radioactivity
                                                              (%)
                                                                        

    methyl-5,6-dihydro-3-H-imidazo                  }
    [2,1-C] 1,2,4-dithiazole-3-thione               }
    (methyl-DIDT)                                   }         8
    (The position of the methyl group is unknown)   }
    Unknown                                         }
    PTU                                                       8
    Propyleneurea (PU)                                        5
    4-methylimidazoline                                      10
    2-methoxy-4-methylimidazoline                             5
                                                                        

         Less PTU was found in the methanol extracts when apples were
    extracted without a prior surface stripping. This may be due to
    partial degradation of PTU during extraction.

         Apple sauce was made from 14C-propineb-treated apples by three
    different methods: (1) not washed before slicing and cooking; (2)
    washed in water for 5 minutes and (3) dipped in water for 5 minutes,
    then in 10 percent NaOH solution for 5 minutes. The propineb
    metabolites in the residue decreased to different extents according to
    the procedure. The metabolites detected were 4-methyl-imidazoline,
    propylenethiourea and small amounts of PTU (about 0.01 mg/kg).
    Methyl-DIDT and 2-methoxy-4-methylimidazoline were not detected in the
    apple sauce.

         The metabolites found on grapes, after surface washing only, and
    in wine are listed in Table 3. The stripping solution contained 27
    percent of the total radioactivity in the grapes.

    METHODS OF RESIDUE ANALYSIS

         The GLC method of analysis for ETU without derivatization,
    developed by Otto et al (1977), was adapted for PTU and improved,
    especially in the extraction procedure, in order to avoid PTU
    degradation during the analysis. PTU is measured directly by GLC,
    using a flame photometric detector operating in the sulpha mode
    (394 nm). The limit of determination is 0.01 mg/kg.

    NATIONAL MAXIMUM RESIDUE LIMITS

         Some national MRLs (Table 4) not included in the 1977 Evaluations
    or amended since then were reported to the meeting. Unless otherwise
    stated, the limits are expressed as CS2. The current preharvest
    intervals for the commodities concerned are also listed.


        TABLE 3.  Propineb Metabolites in Grapes and Wine

                                                                                                                          

    Metabolite 1        I         II        VI        VII       VIII      IX        X         not            not
                                                                                              identified     extractable
                                                                                                                          

    Commodity

      grapes %          41                  9         7         1.2       5         4           9              18 6
          mg/kg         13        1.1       0.6       0.15      0.5       0.5       1.9         5.6 2           1.9

      wine  %                     2        25        13                  12                    48
          mg/kg                   0.03      0.3       0.15                0.2
                                                                                                                          

    1 - propineb; II - PTU; VI - methylimidazoline; VII - N-formylpropylene-diamine; VIII - 2-methoxy-4-methylimidazoline;
        IX - propyleneurea (PU); X - methyl-DIDT
    2  In propineb equivalents
    
        TABLE 4.  National MRLs Reported to the Meeting

                                                                                              

    Country        Commodity                         MRL              Preharvest interval
                                                     (mg/kg CS2)      (days)
                                                                                              

    Australia      Citrus fruit                      0.2              7

    Austria        Fruits                            2                (grapes) 14
                   Vegetables                        2                14
                   Other food crops                  0.05

    Belgium        Fruits (except citrus}            2                28
                    Currants (red, white)                             28
                    Other small fruit                                 14
                   Vegetables                        2
                    Fruiting vegetables                               3
                    Other vegetables                                  28
                   Cereals                           0.1

    Brazil         Apples, pears                     3.0              7
                   Peaches                           3.0              7
                   Plums                             1.0              7
                   Grapes                            5.0              7
                   Strawberries                      3.0              7
                   Bananas (whole fruit)             1.0              7
                   Bananas (pulp)                    0.1              7
                   Cucumbers                         0.5              7
                   Melons                            1.0              7
                   Beans, carrots                    0.5              7
                   Potatoes                          0.1              7
                   Wheat                             0.2              7

    France         Cucumbers, melons                 0.1              7
                   Tomatoes                          2.0              7
                   Lettuce                           3.0              15
                   Celery                            0.5              15
                   Beans                             0.5              7

    German         Pome fruit, stone fruit           3.0
    Democratic     Small fruit and berries           3.0
                   Citrus fruit                      0.1
                   Brassicas, fruiting
                    vegetables, leafy vegetables
                    legumes, root vegetables,
                    stem vegetables                  3.0
                   Root vegetables (except
                   potatoes)                         3.0
                   Potatoes                          0.1              10
                                                                                              

    TABLE 4.  (continued)

                                                                                              
    Country        Commodity                         MRL                  Preharvest interval
                                                     (mg/kg CS2)          (days)
                                                                                              

                   Nuts                              3.0
                   Cereals, milled cereal
                    products                         0.1
                   Eggs, meat, milk                  0.1
                   Fish                              0.1
                   Animal and vegetable fats         0.1
                   Food crops for infant diets       0.1

    Federal        Fruits                            2.0
    Republic       Vegetables (except cucumbers
    of Germany      and tomatoes)                    2.0
                   Cucumbers, tomatoes               1.0                  7
                   Potatoes                          0.2                  7
                   Other food crops                  0.2

    Hungary        Apples, pears                     2.0                  30
                   Grapes                            2.0                  30
                   Cucumbers                         2.0                  5
                   Peppers, tomatoes                 3.0                  7
                   Peppers, tomatoes for
                    industrial processing            5.0                  5
                   Hops (dry)                        80                   14
                   Mushrooms                         2.0                  2

    Japan          Fruits                            0.71 calculated      45-60
                   Vegetables                        0.11 as propineb     7

    Luxembourg     Fruits                            2
                   Vegetables (except cucumbers,
                   tomatoes)                         2
                   Cucumbers, tomatoes               1

    Netherlands    Currants (red, black, white),
                   other small fruits                3
                   Other fruit                       2 1
                   Lettuce                           4 2
                   Cucumber, melon                   1
                   Bulb vegetables                   0.5
                   Legume vegetables                 0.2
                   Other vegetables                  2 1
                   Cereal grains                     0.5
                   Potatoes                          0.2
                   Other food crops                  0 (0.2)
                   All food commodities              PTU 0.02 mg/kg
                   Heat/treated food                 PYU 0.1 mg/kg
                                                                                              

    TABLE 4.  (continued)

                                                                                              

    Country        Commodity                         MRL              Preharvest interval
                                                     (mg/kg CS2)      (days)
                                                                                              

    South Africa   Grapes                            3
                   Grapes (table)                    3                14(28-42)
                   Loganberries, youngberries        3                14
                   Tomatoes                          3                3
                   Potatoes                          0.5              3
                   Peanut hay                        3                21

    Sweden         Fruits, including berries         1
                   Vegetables (except carrots)       1
                   Carrots                           0.3

    Switzerland    Fruits                            2                21
                   Vegetables                        2                7-21
                   Potatoes                          0.05
                   Cereal grains                     0.1
                   Tobacco                           50
                                                                                              

    1  of which no more than 0.5 mg/kg from a PTU precursor
    2  of which no more than 2 mg/kg from a PTU precursor
    

    APPRAISAL

         The meeting reviewed information on residue levels of propineb
    from supervised trials on various crops, mainly from the Federal
    Republic of Germany. The residue level of propylenethiourea (PTU) was
    evaluated in these trials. The latter compound can occur as a
    metabolite of propineb on plants or as an impurity in technical
    propineb.

         Additional information was obtained on the metabolic pathway of
    propineb in plants, especially apples and grapes. Several metabolites
    and intermediate products were identified and the most probable
    pathway of residue degradation was elucidated in more detail. Some new
    information was also obtained on improved methods of residue analysis
    for PTU in commodities of plant origin.

         The meeting examined residue data from supervised trials
    reflecting good agricultural practice on apples, pears, sour cherries,
    peaches, plums, grapes, celeriac (root and leaves), potatoes and
    tomatoes.

    RECOMMENDATIONS

         From the available data, the meeting concluded that the maximum
    residue levels of propineb expressed as CS2 were similar to the TMRLs
    established for the ethylene bisdithiocarbamates.

         In addition, the meeting recommended the following estimated
    maximum residue level as a TMRL:

                                                                    

    Commodity           TMRL (mg/kg)   Preharvest interval on which
                                       recommendations are based
                                                                    

    Celeriac (roots)    0.1            14
                                                                    

         This proposal is not included in the current temporary MRLs for
    the ethylenebisdithiocarbamates.

         The meeting estimated the following maximum residue levels of PTU
    from supervised trials in which propineb was applied according to good
    agricultural practice. In the absence of an ADI for PTU, or propineb
    including PTU, these are recorded as guideline levels. They refer only
    to PTU.

                                                                      
    Commodity           Guideline level     Preharvest interval on
                        (mg/kg as PTU)      which GL is based
                                                                      
    Apples                   0.1                    10
    Pears                    0.1                 17-21
    Cherries, sour           0.1                 14-21
    Peaches                  0.05                   14
    Plums                    0.1                  7-14
    Grapes                   0.1                 28-35
    Celeriac                 0.05                   14
    Potatoes                 0.02                 7-10
    Tomatoes                 0.1                   3-7
                                                                      

    FURTHER WORK OR INFORMATION

    Desirable

    1.   Further development and validation of the methods of analysis for
         the separate determination of ethylenebisdithiocarbamates and
         propylenebisdithiocarbamates, which are ETU and PTU precursors.
         The meeting was informed that work was in progress in some
         countries to meet the 1980 JMPR requirement for such methods to
         be provided by 1983 and recognized the problems met in the
         development of them.

    2.   Residue data, on a few crops, obtained by use of a specific
         method for ETU and PTU precursors to be compared with data
         obtained by the validated head space CS2 GLC procedure.

    3.   Residue data from crops on which the ETU or PTU precursors are
         used simultaneously or alternately with other fungicides, e.g.
         thiram, which are not ETU precursors. Emphasis should be given to
         crops that are in general household-cooked or heat-processed,
         e.g. some leafy vegetables, apples and tomatoes.

    REFERENCES

    Bayer Reports on residues from supervised trials. Submitted by Bayer
    1978-1983   AG to FAO. (Unpublished)

    Dreze, P. & Vogeler, K. Studies on the metabolism of propineb in and
    1979        on apples and in the apple sauce preparation process.
                Report RA-542 submitted by Bayer AG to FAO. (Unpublished)

    Otto, S., Keller, W. & Drescher, N. A new gas chromatographic
    1977        determination of ethylenethiourea residues without
                derivatization. J. Environ. Sci. Health, B12 (3): 179-191.

    Vogeler, K. Report on hitherto conducted studies on propineb
    1980        metabolism on and in plants. Report RA-16 submitted by
                Bayer AG to FAO. (Unpublished)


    See Also:
       Toxicological Abbreviations
       Propineb (Pesticide residues in food: 1977 evaluations)
       Propineb (Pesticide residues in food: 1985 evaluations Part II Toxicology)
       Propineb (Pesticide residues in food: 1993 evaluations Part II Toxicology)