Sponsored jointly by FAO and WHO


    Joint meeting of the
    FAO Panel of Experts on Pesticide Residues
    in Food and the Environment
    and the
    WHO Expert Group on Pesticide Residues
    Geneva, 3-12 December 1979



    The 11th Session of the CCPR noted that the 1978 Meeting had reduced
    the temporary MRL on apples and pears from 3 mg/kg to 2 mg/kg.  The
    U.S.A. delegation promised to make data available to support a higher
    limit.  This addendum is an assessment of the data provided.

    USE PATTERN: Pre-harvest (USA)

                 Dose rate              No. of           Interval
    Crop         lb. a.i./A          applications        PHI Days

    Apples       1.3-3.6 (WP)              3                  7
                 1.25-3.75 (EC)            3                  7

    Pears        0.90-2.25 (WP)            2                 14


    Residue data for propargite on apples were made available from the
    United States, some of which may have been examined previously.  There
    are two sets of data.  The first (1) gives residues at a 7-day PHI
    which reflects U.S. agricultural practices.  Those data which most
    nearly reflect the U.S. dosage rate are summarized in Table 1 for both
    a wettable powder formulation and an emulsifiable concentrate.  They
    have also been adjusted in the last column to the maximum U.S. dosage.
    The adjusted values for the 57E give a strong indication that residues
    can be on the order of 3 mg/kg from U.S. agricultural practices.

    The second set of data (2) are less useful in that they are at one day
    instead of 7 days.  These are tabulated in Table 2 by the range of 5
    replicate analyses from each of five states.  The mean value given is
    the mean of the five replicates adjusted to 7 days assuming a
    half-life of 6 days.  This is a reasonable estimate of a half-life on
    apples which is suggested by data in the 1977 Evaluations.  Data in
    the 1978 Evaluations indicate that the disappearance is actually
    minimal within 7 days.  Again, these mean values indicate that
    residues could reasonably be expected to exceed 2 mg/kg at 7 days. 
    This is even more strongly indicated if the mean values are adjusted
    to maximum U.S. dosage.  These values are given in the last column of
    Table 2 and actually indicate that residues could approach 4 mg/kg at
    7 days.

        Table 1.  Propargite - Apples

                   30 W (Wettable powder)         57E (Emulsifiable concentrate)
                   residue         adjusted       lb.a.i./A      residue         adjusted
    lb.a.i./A       mg/kg          residue                        mg/kg          residue

       4.8           1.6             1.2             4.4            -               -
       4.8            -               -              4.4           2.1             1.8
       3.0           1.6             1.9             2.3           2.4             3.3
       2.4           0.8             1.2             2.2           1.7             2.9
       2.4           0.9             1.3             2.2           1.5             2.5
       2.4           0.5             0.75            2.2           0.5             0.85

    Table 2. Propargite - Apples

                                    30 W                                           57E
                   lb.a.i.         Residue                       Mean            lb.a.i.        Residue
                   per Acre        range          Meanb          adj.c           per Acre       range          Meanb      Mean
                                   mg/kga                                                       mg/kga                    adj.c
    Vermont          2.1           2.1-3.3         1.3            2.2              2.2          3.2-6.5        2.5         4.3

    Pennsylvania     2.4           2.2-6.3         1.9            2.8              2.5          2.2-4.5        1.6         2.4

    Indiana          2.4           0.4-1.5         0.36           0.54             2.5          0.6-1.9        0.51        0.77

    California       3             3-4.6           1.9            2.3              3.1          2.9-4.8        1.8         2.1

    Oregon           3             1.9-2.4         1.1            1.3              3.1          3.8-5          2.1         3.5

    Pennsylvaniad                                  1.5

    Vermontd                                                                                                   2.3         4.0

    a  Residue range at one day from given dosage;

    b  Mean of 5 replicates for each state adjusted to 7 days assuming a 6-day half-life;

    c  Mean of b adjusted to maximum U.S. dosage;

    d  Data if high residue value is omitted.


    Additional residue data from the use of propargite on apples was
    received from the U.S.A. although some of this data may have been
    examined in 1977.  One set of data from the use of an emulsifiable
    concentrate indicate that residues can be at or slightly above 2 mg/kg
    from dosages less than permitted at the pre-harvest interval of 7
    days.  When adjusted to maximum U.S. dosage rates, residues around 3
    mg/kg are indicated.  Other data, adjusted to U.S. usage suggest
    maximum residues around 4 mg/kg at 7 days.

    The discrepancy between conclusions in the 1977 Evaluations which
    recommended a temporary MRL of 3 mg/kg for apples and pears and the 2
    mg/kg recommended by the 1978 Evaluations and further the
    inconsistency with the interpretation of data available at this
    meeting, is not entirely clear.  However, the dosage rate appears a
    key factor.

    The 3 mg/kg recommended in 1977 was based on 0.03-0.06% application
    rates.  Even here a maximum value of 2.4 mg/kg is given at 14 days as
    well as a 6.3 mg/kg value at 0-1 day.  It is recognized that there
    were many samples analyzed.  The basis for lowering the temporary MRL
    to 2 mg/kg by the 1978 Evaluations apparently is the additional data
    submitted which did show residues just under 1 mg/kg around 7 days
    after treatment.  However, the monograph does not indicate the dosage
    on some of the studies and for those where it is given, it is about
    1/8 of that permitted in the U.S.

    It is also noteworthy that recommendations for other tree fruits at 7
    mg/kg from similar dosages as recommended for apples, even though
    these limits are based on a 14-day pre-harvest interval.  On the basis
    of the information before the meeting, it appeared that good
    agricultural practices in the U.S. can result in residues exceeding 2
    mg/kg possibly approaching 4 mg/kg.


    It is recommended that the temporary MRL on apples and pears be
    revised as follows:

           Commodity                       Limit (mg/kg)

           Apples, pears                        5



    The carcinogenicity study required by the 1977 Meeting.


    The first two items listed by the 1977 Meeting and the items listed by
    the 1978 Meeting.


    (1)  Data from Section D of US petition No. 569 as made available by
    Uniroyal Chemical, Division of Uniroyal, Inc., Agricultural Chemicals
    Research and Development, 74 Amity Road, Bethany, Connecticut 06525,
    October 9, 1979.

    (2)  Data from Section D of US petition No. 730 as made available by
    Uniroyal Chemical, Division of Uniroyal, Inc., Agricultural Chemical
    Research and Development, 74 Amity Road, Bethany, Connecticut 06525,
    October 9, 1979.

    See Also:
       Toxicological Abbreviations
       Propargite (Pesticide residues in food: 1977 evaluations)
       Propargite (Pesticide residues in food: 1978 evaluations)
       Propargite (Pesticide residues in food: 1980 evaluations)
       Propargite (Pesticide residues in food: 1982 evaluations)
       Propargite (JMPR Evaluations 1999 Part II Toxicological)