IPCS INCHEM Home


    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

    IMAZALIL

    Explanation

         Imazalil was reviewed by the Joint Meeting in 1977 and 1980 1/.
    At the 1977 JMPR a temporary ADI was allocated and temporary maximum
    residue limits were proposed for a small number of commodities such as
    bananas, citrus fruit (both post-harvest treatment) and cereal grains
    (seed-dressing). The 1980 meeting reaffirmed the TMRLs proposed in
    1977 and extended the TADI.

         Since these evaluations the use pattern has been expanded in many
    countries, especially with respect to post-harvest uses on fruits and
    fruiting vegetables. New data were provided to the 1984 JMPR on
    residues from supervised trials on a number of these crops, namely
    pome fruit, kaki fruit (persimmons), cucumbers, melons and tomatoes;
    also on residues from trials on seed potatoes (seed-dressing) and on
    pre-harvest foliar applications to strawberries and raspberries.

         Information was also obtained on the current status of the
    authorisation or registration in several countries and on current
    national maximum residue limits.

    RESIDUES IN FOOD AND THEIR EVALUATION

    USE PATTERN

         Imazalil is used as a fungicide against storage rots by post-
    harvest application (drench, dip or wax treatment on various fruits
    and fruiting vegetables), as a pre-harvest foliar application to some
    fruits and vegetables and as a seed-dressing on cereal grains, cotton
    seed and seed potatoes.

         The main formulations used are EC (emulsifiable concentrate),
    200, 500 and 800 g/l, WP (wettable powder) 50 and 75%, an oil ULV
    formulation (about 500 g/l) and an LS (solution for seed treatment),
    ca. 100 g/l.

         The main uses are summarized in Table 1.

              

    1/  See Annex 2 for FAO and WHO documentation.


        Table 1.  Use pattern of Imazalil

                                                                                                                                        
                                                                                      Application
    Commodity                          Disease/Pathogen                        Rate                Type              Formulation
                                                                                                                                        

    1. Post-harvest application

    Apples and               Storage decay       Botrytis cineria              30-50 g/100 l       dip               LS 100 g/l
    pears                                        Monilia fructigena                                drench            WP 75%
                                                 Pencillium expsnsum                               Spray             EC 500 g/l
                                                 Alternaria tenuis

    Bananas                  Anthracnose         Collectorichum musae          30-50 g/100 l       dip               WP 75%
                             Crown and           Fusarium semitecrum                               drench
                             Finger rot          F. roseum                                         spray
                             Neck rot            Verticillium theobromae
                                                 Ceratocysti C paradoxa
                                                 Botriodiploclia theobromae

    Citrus                   Green mould         Penicillium digitatum         1 000-              in wax, dip       EC 800 g/l
    fruit                    Blue mould          Penicillium italicurn         2 000 mg/kg         drench,
                             Phomopsis stem      Diaporthe citri               25-100 g/100 l      spray             95% Tech.
                             end rot
                             Diplodia rot        Diplodia natalensis                                                 WP 75%
                             Alternaria rot      Alternaria citri

    Peach                    Storage decay       Monilia fructigena            625 mg/kg           in wax            EC 500 g/l
                                                 Penicillium expansum
                                                 Gloeosporium spp.

    Pineapple                Stem-end rot        Thielaviopsis paradoxa        15-20 g/100 l       dip               WP 75%

    Melons                   Storage rot         Fusarium solani               50 g/100 l          dip               WP 75%
                                                 Alternaria spp.               1 000 mg/kg         in wax            75% Tech.

    Tomatoes                 Grey rot            Botrytis cineria              10-100 g/100 l      dip               WP 75%
                             Alternaria rot      Alternaria alternata
                                                                                                                                        

    Table 1.  (Continued)

                                                                                                                                        
                                                                                      Application
    Commodity                          Disease/Pathogen                        Rate                Type              Formulation
                                                                                                                                        

    II. Foliar Application, Pre-harvest

    Bananas                  Sikatoga            Myucosphaerella musicola      100-250 g/ha        spray             ULV 50%
                             Black               M. fiiiensis var                                  ULV in oil
                             Sikatoga            difformis
                             Black leaf-streak   M. fijiensis

    Peach                    Powdery mildew      Sphaerotheca pannosa          30 g/l00 l          spray             EC 500 g/l

    Strawberries             Powdery mildew      Sphaerotheca macularis        30-40 g/100 l       spray             EC 200 g/l
                                                 S. alchemilla
                             Leaf spot           Alternaria alternata
                                                 Gnomonia comari
                                                 Diplocarpon earlianum

    Cucumbers                Powdery mildew      Sphaerotheca fuliginae        5-10 g/100 l        spray             EC 200 g/l
                             Grey mould          Botrytis cineria
                             Stem and )          Uidmella bryoniae
                             fruit rot)          Mycosphaerella citrulina

    Peppers                  Powdery mildew      Oidiopsis tauriea             10-30 g/100 l       spray             EC 200 g/l

    III. Seed Dressing

    Cereal seed              Leaf Stripe         Helminthosnorium sp           5 g/100 l           spray             various
                             Fusarium spp.
                             Septoria spp.

    Cotton seed              Thielaviopsis basicola                            20-30 g/100         spray             LS 100 g/l
                             Fusarium spp.                                     kg seed
                             Verticillium al bo-atrum
                                                                                                                                        

    Table 1.  (Continued)

                                                                                                                                        
                                                                                      Application
    Commodity                          Disease/Pathogen                        Rate                Type              Formulation
                                                                                                                                        

    Seed Potatoes            Skin spot           Polyseytalum pustulans        10-30 g/1000 kg     spray             WP 75%
                             Gungrene            Phoma exigua var foveata      kg
                             Silver scurf        Helminthosporium solani                           ULV
                             Dry rot             Fusarium solani
                                                 Fusarium sulphureum
                                                                                                                                        
    
    RESIDUES RESULTING FROM SUPERVISED TRIALS

         Data on residues resulting from post-harvest uses on apples,
    pears and some fruiting vegetables (cucumbers, melons, sweet peppers
    and tomatoes) were obtained from various countries in Europe and
    America (Tables 2-4).

         Data on residues resulting from post-harvest uses on seed
    potatoes are given in Table 5, and on residues from pre-harvest uses
    on raspberries and strawberries from two countries in Table 6.

    Post-harvest uses

    Apples and pears.  The initial residues show some variation,
    depending on the mode of application (dip, drench or spray), whether
    or not in combination with a wax treatment on the fruit size and skin
    texture.

         The maximum residue level found if the fungicide is used
    according to good (storage) practice is about 5 mg/kg of imazalil
    parent compound.

         Under good practical storage conditions the initial residue
    hardly decreases (at temperatures of about 2-5C, in the dark or in
    poor light). The apparent increase of residue after relatively long
    storage periods is mainly due to a loss of weight caused by
    evaporation.

    Kaki (persimmons).  Initial residues resulting from use according to
    good practices are of the order of 2 mg/kg. This residue hardly
    decreases under normal storage conditions e.g. at low temperatures
    (1-5C).

    Fruiting vegetables.  In cucumbers, melons, sweet peppers and
    tomatoes, the maximum residue levels resulting from uses according to
    good storage practices were about 3-4 mg/kg (dip, drench or spray with
    imazalil WP or EC in water at dosage rates of 250 to 1,000 mg. a.i/l;
    combined wax + imazalil treatment at 2,000 mg/l).

         During storage under normal conditions (at temperatures of about
    1C or slightly above, in the dark) the residue decreased only very
    slightly, if at all.

    Seed potatoes.  Since seed potatoes which do not meet the 
    seed-potato quality standard (especially those too small or too large)
    are commonly used as food or feed, the establishment of an MRL may be
    desirable.


        Table 2.  Residues of imazalil in apples from trials carried out in the USA in 1982

                                                                                                                                      
                                                                                Residues, mg/kg
    No. of             Application          Storage                                                                    
                                            period               Imazalil                        T 8241
    trials         Rate      Formulation                                                                               
    (Replicates)   mg a.i./l                (weeks)        Whole2    Peel      Pulp      Whole     Peel      Pulp
                   or /kg                                  fruit                         fruit                         Ref.
                                                                                                                                      

    1 (5)          1 000     WP 75%            0           1.36      -         -          0.02      -         -        Hamilton,
                   dip                         1           1.76      7.85      1.19       0.09      0.11      0.91     1983a
                                               2           1.10      5.85      0.70      <0.01      0.11     <0.01
                                               4           0.97      4.06      0.66       0.09      0.13      0.09
                                               6           0.72      3.85      0.38       0.03      0.06      0.03

    1 (5)          500       WP 75%            0           0.96      -         -          0.04      -         -
                   dip                         1           0.83      4.37      0.53       0.05      0.11      0.04
                                               2           3.45      3.94      3.41      <0.01      0.10     <0.01
                                               4           0.57      4.83      0.15       0.04      0.15      0.03
                                               6           0.59      2.76      0.39       0.02      0.06      0.01
    1 (5)          1 020     EC 680 g/l        0           2.11      -         -          0.08      -         -
                   dip                         1           4.56      7.67      4.29       0.03      0.09      0.03
                                               2           4.18     11.0       3.54       0.11      0.12     <0.01
                                               4           2.07     11.8       1.02       0.03      0.14      0.02
                                               6           1.57      6.98      1.02       0.04      0.09      0.03

    1 (5)          720       Formulation       0           1.51      -         -          0.08      -         -
                             1211-3            1           2.33     16.7       1.27      <0.01      0.08     <0.01
                                               2           2.21      8.86      1.43       0.01      0.13     <0.01
                                               4           1.27      7.82      0.74       0.06      1.64      0.05
                                               6           1.39      3.65      1.19       0.04      0.06      0.04

    1 (5)          950       Imazalil          0           1.60      -         -          0.18      -         -
                   in wax    base              1           3.96      9.63      3.47       0.29      1.06      0.22
                                               2           1.94      7.12      1.51       0.09      0.08      0.09
                                               4           1.07      3.24      0.78       0.05      0.11      0.04
                                               6           1.77      6.44      1.38       0.05      0.14      0.04
                                                                                                                                      

    Table 2 (continued)

                                                                                                                               

                         Application                          Residues, mg/kg, average and (range)
    No. of                                     Storage                                                          
    trials         Rate        Formulation     period         Imazalil              T 8241
    (Replicates)   mg a.i./l                   (weeks)                                                          
                   or /kg                                     Whole fruit3          Whole fruit3             Ref.
                                                                                                                               

    1 (2)          500         WP                0             1.24                 <0.01                    Hamilton,
                                                                                   (<0.01 - <0.01)           1983b

                                                 1             1.20                  0.025
                                                              (1.52 - 0.96)

                                                 2             1.16                  0.06
                                                 4             4.41                  0.22
                                                 8             2.01                  0.18

    1 (2)          1 000                         0             2.48                  0.03
                                                              (1.48 - 3.47)        (<0.01 - 0.05)

                                                 1             2.79                  0.05
                                                 2             3.83                  0.02
                                                 4             2.57                  0.04
                                                 8             2.88                  0.02

    1 (2)          4 000                         0             5.54                  0.022
                                                              (4.98 - 6.09)         (0.021 - 0.022)

                                                 1             9.25                  0.07
                                                 2             7.00                  0.06
                                                 4             9.39                  0.14
                                                 8            11.5                   0.35
                                                                                                                               

    1  T 824 = 1-(2,4-dichlorophenyl)-2-imidazol-l-ylethanol
    2  Calculated frcm the peel and pulp figures
    3  Residues in these trials determined directly on the whole fruit.

    Table 3.  Residues of imazalil in apples, pears and persimmon, from trials outside the USA, 1979-1984

                                                                                                                                           
                                              Application
                                                               
    Commodity      Country        Year    Rate,     Formulation     No. of trials    Storage       Residues,                     Reference
                                          mg a.i/l                  trials           period,       mg/kg,
                                                                    (replicates)     months or     average and (range)
                                                                                     (days)
                                                                                                                                           

    Apple          Israel         1979    400                       1 (3)            0             0.24 (0.20 - 0.28)            State Residue
                                          dip                                        2             0.28 (0.20 - 0.36)            Lab.
                                                                                     4             0.37 (0.28 - 0.40)

                                          800                       1 (3)            0             0.47 (0.30- 0.60)
                                          dip                                        2             0.37 (0.20 - 0.42)
                                                                                     4             0.44 (0.38 - 0.50)

                   Sweden         1982    1,200                     1                (1)           7.5                           Nordalkali
                                          dip                                        (10)          5.5
                                                                                     (31)          5.2
                                                                                     (93)          8.01

                   Belgium        1983    500      WP 75% and       1                0             1.80 (1.50 - 2.04)            Janssen
                                                   EC 500 g/l                        5.5           2.04 (1.82 - 2.34)
                                                                                                   2
                                                                                                   T824 <(1.01

    Pear           Australia      1983    250       WP and          1 (2)            -             0.7   0.35                    Anal chem
    Var.                                  375       mixture with    1 (2)                          1.2   1.3
    Packham                               500       DPA and         1 (2)                          1.3   1.4
                                                    ethoxyquin                                     T 824 <0.02 - 0.04
    Var. Beurre                   1983    250       WP and          1 (2)                          2.0   3.5                     Analchum
    Bosc                                  375       mixture with    1 (2)                          2.2   3.6
                                          500       DPA and         1 (2)                          3.1   3.9
                                                    ethoxyquin                                     T 824 <0.02 - 0.4

                                                                                                                                           

    Table 3.  (continued)

                                                                                                                                           
                                              Application
                                                               
    Commodity      Country        Year    Rate,     Formulation     No. of trials    Storage       Residues,                     Reference
                                          mg a.i/l                  trials           period,       mg/kg,
                                                                    (replicates)     months or     average and (range)
                                                                                     (days)
                                                                                                                                           

    Var. Packham                  1983    500       WP and          1 (2)                          1.3   1.2                     Analchum
                                                    mixture with
                                                    DPA and
                                                    ethoxyquin

    Var. Beurre                   1983    500       "               1 (2)                          4.3   6.1                     Analchem
    Bosc

    Var. Packham                  1983    500       WP ?            1 (2)                          1.0   1.6                     Analchem
                                                                                                   T 824   <0.05

    Var. Beurre                   1983    500       WP ?            1 (2)                          3.1   2.2                     Analchem
                                                                                                   T 824 0.05 - 0.07

    Var.           Belgium        1983/84 500       WP and          1 (2)            0             2.74  3.15                    Janssen
    Conference                            dip       EC 500 g/l                                     T 824  <0.01

    Persimmon      Israel         1979    500                       1 (3)            4  )          0.79 (0.75 - 0.87)            AGAN
    (kaki)                                dip                                        67 )          0.66 (0.56 - 0.75)
                                                                                     87 )          0.51 (0.13 - 0.95)
                                                                                     112)          1.2 (0.7 - 1.6)
                                                                                     (stored at -1C)
                                                                                     4  )          1.2 (0.9 - 1.5)
                                                                                     67 )          0.81 (0.72 - 0.95)
                                                                                     87 )          0.79 (0.52 - 1.12)
                                                                                     112)          1.2 (0.96 - 1.64)
                                                                                     (stored at -1C)
                                                                                                                                           

    1  Apparent increase of residue mainly casued by loss of weight due to evaporation
    2  See Table 2, footnote 1.

    Table 4.  Residues of imazalil in fruiting vegetables from trials in various countries 1982-1983

                                                                                                                                           
                                             Application
                                                                
    Commodity      Country        Year    Rate,     Formulation     No. of trials    Storage       Residues,                     Reference
                                          mg a.i/l                  trials           period,       mg/kg,
                                                                    (replicates)     months or     average and (range)
                                                                                     (days)
                                                                                                                                           
    Fruiting Vegetables

    Melons         USA            1982/   1 000     EC 220 g/l      2                -             1.26  (1.24 - 1.28)           Pennwalt
    (cantaloupes}                 83      in wax

                                          2 000                     2                -             2.27  (2.14 - 2.40)
                                          in wax

                                          4 000                     2                -             4.72 (4.70 - 4.73)
                                          in wax

                   Israel         1983    1 000     WP 75%          1 (3)            2                                           AGAN
    Peel                                                                                           3.4 (3.0 - 4.0)               Weight
    Pulp                                                                                           0.1  (<0.01 - 0.2)            Pulp/peel
                                                                                                                                 =2.7

    Cucumber       USA            1982    in wax Imazalil           1 (2)                          0.62 (0.58 - 0.66)            Penwalt
                                          1.5 mg a.i. tech. 98.2%
                                          /kg fruit

                                          3 mg a.i.                 1 (2)                          1.17 (1.10 - 1.24)
                                          /kg fruit

                                          6 mg a.i.
                                          /kg fruit                 1 (2)                          2.28 (2.28 - 2.28)

    Peppers        USA            1982    1 500) Imazalil           1 (2)            -             1.49 (1.47 - 1.50)            Penwalt
                                          3 000) tech                                              2.05 (2.00 - 2.10)
                                          6 000) 98.2%                                             4.25 (4.20 - 4.30)
                                          in wax
                                                                                                                                           

    Table 4.  (continued)

                                                                                                                                           
                                             Application
                                                                
    Commodity      Country        Year    Rate,     Formulation     No. of trials    Storage       Residues,                     Reference
                                          mg a.i/l                  trials           period,       mg/kg,
                                                                    (replicates)     months or     average and (range)
                                                                                     (days)
                                                                                                                                           
                   Israel         1983    1 000 WP 75%              1 (3)            4             2.4 (1.8 - 2.7)               AGAN
                                                                                     17            2.3 (2.11 - 2.5)
                                          2 000 WP 75%              1 (3)            4             5.0 (4.0 - 6.0)
                                                                    1 (3)            17            2.3 (1.8- 2.7)

                   USA            1982    50 drench                 1 (2)            0             0.52  0.07                   USDA
                                                                                     3             0.40  0.08
                                                                                     6             0.25  0.05
                                                                                     12            0.05  0.02

                                          100 drench                1 (2)            0             0.55  0.22
                                                                                     3             0.61  0.1
                                                                                     6             0.25  0.02
                                                                                     12            0.11

                                          250 drench                1 (2)            0             1.51  1.23
                                                                                     3             1.35  0.27
                                                                                     6             0.56  0.07
                                                                                     12            0.28

    Tomatoes       USA            1982    1 500 )                   1 (2)            0             1.22 (1.22 - 1.22)            Pennwalt
                                          3 000 )                   1 (2)                          1.71 (1.60 - 1.82)
                                          6 000 )                   1 (2)                          2.60 (2.40 - 2.80)
                                          in wax

                   USA            1983    250   )                   1 (2)            2 hours       0.32                          Brogdex
                                          500   )                   1 (2)            "             0.39
                                          750   )                   1 (2)            "             0.44
                                          1 000 )                   1 (2)            "             0.42
                                          in wax
                                                                                                                                           

    Table 4.  (continued)

                                                                                                                                           
                                             Application
                                                                
    Commodity      Country        Year    Rate,     Formulation     No. of trials    Storage       Residues,                     Reference
                                          mg a.i/l                  trials           period,       mg/kg,
                                                                    (replicates)     months or     average and (range)
                                                                                     (days)
                                                                                                                                           

                   USA            1983    2 000 )                   1                0             1.67                          Brogdex
                                          2 500 )                   1                0             2.54
                                          3 000 )                   1                0             1.89
                                          in wax

                                  1983    2 500 )                   1                0             0.63
                                          3 000 )                   1                0             0.90
                                          3 500 )                   1                0             1.76
                                          in wax

                                  1983    2 500 )                   1                0             0.89
                                          5 000 )                                                  2.39
                                          7 500 )                                                  6.12
                                          in wax
                                                                                                                                           

    Table 5. Residues of imazalil in seed potatoes from trials in Europe, 1978-19Fk4

                                                                                                                                           
                                                Application                          Residues, mg/kg, mean and range)
                                                                                                                         
    Variety   Country         Year    No.   Rate,                    Time after     Whole Potato    Peel           Pulp          Reference
                                            g a.i/    Formulation    treatment,
                                            tonne                    months
                                                                                                                                           
    Resy      France          1979    1     5.25      EC             1              2.90 )          11.01 )        0.07          La Quino
                                      1     10.5      EC             1              9.10 )          39.06 )        0.15          Line
                                                                                    (unwashed       (unwashed)

    Bintje    France          1979    1     5.25      EC             1              0.50 )          1.92 )         0.08
                                      1     10.25     EC             1              1.90            7.87           0.07
                                                                                    (unwashed)      (unwashed)

              France          1978    1     20        EC             4              10.28 )         45.4  )        0.16          Schering
                                            40        EC             4              30.34 )         138.8 )        0.47
                                            60        EC             4              47.50 )         213.6 )        0.87
                                            80        EC             4              53.74 )         229.5 )        1.07
                                                                                    (unwashed)      (unwashed)

              Netherlands     1984    1     15        EC 220 g/l     1              3.91            37.4           0.05          Janssen
                                                                                    (3.78-4.07)     (36.6-38.3)    (0.04-0.05)
                                      1     15        EC 200 g/l     2              4.29            39.6           0.045         Janssen
                                                                                    (4.00-4.47)     (35.7-45.1)    (0.04-0.05)

              UK              1980    1     10        EC 200 g/l     0              4.22 (2.12-5.27)                             Cayley
                                                                     35 weeks       1.24 (0.71-2.10)*                            et al
                                                                     35 weeks       0.84 (0.47-1.20)**

                              1980    1     10        EC 200 g/l     0              2.50
                                      1     10        EC 200 g/l     0              5.5

              UK              1983    1     15        EC 200 g/l     4.5            0.443           2.76           0.03
                                                                                                    (2.38-3.06)
                                                                                                                                           

    *  Sample brushed before analysis.
    ** Sample washed before analysis.

    Table 6.  Residues of imazalil in raspberries and strawberries from trials in Europe, 1978-83
              (Pre-harvest foliar application)

                                                                                                                                           
                                                 Application
                                                                       
    Commodity      Country        Year      Rate,          Formulation    No. of         PHI,      Residues,                Reference
                                            g ai/ha or                    trials         days      mg/kg,
                                            g ai/100 l                                             average and (range)
                                                                                                                                           

    Raspberries    UK             1978      10 g/100 l     EC             1              7            0.94                  Hazleton
                                                                                         14           0.09

                   UK             1980      10 g/100 l     EC             1              7            0.32                  Hazleton
                                                                                         14           0.22

    Strawberries   Belgium        1983      400 g/ha       EC 200 g/l     1              Before       1.21                  Janssen
                                                                                         spraying
                                                                                         after
                                                                                         0            2.0
                                                                                         3            1.4
                                                                                         5            1.0
                                                                                         7            1.2
                                                                                                                                           

    1  Sampled one week after the last of 12 sprayings
    

         Residues resulting from treatment according to current
    recommendations ranged from 2.5 to 5.0 mg/kg depending on the mode of
    preparation of the sample before analysis. Residues above 5 mg/kg were
    only found when samples were not washed before analysis as recommended
    in the FAO Guidelines on residue trials for root and tuber vegetables.
    The residue level in washed potatoes or potatoes cleaned by other
    adequate methods was not in general above 5 mg/kg.

    Foliar, pre-harvest application

    Raspberries.  Raspberries treated at recommended dosages, about
    10 g a.i/100 l, showed residues of 0.04-0.3 mg/kg seven days after
    such treatment, and the residue after 14 days was of the same order
    (0.09-0.2 mg/kg).

    Strawberries.  Strawberries treated at recommended dosages (about
    400 g a.i./ha) contained residues of 1.2-2.0 mg/kg 0-7 days after the
    last application.

    Fate of Residues

    In plants.

         Van Leemput et al. (1984) evaluated the transformation of
    14C-imazalil on Golden Delicious apples. Apples were dipped in a
    500 mg/l 14C-imazalil solution and subsequently kept in controlled
    atmospheric storage for four months.

         Another set of apples was treated with unlabelled imazalil. The
    apples treated with labelled imazalil were used for the identification
    of metabolites and for determining the efficiency of the analytical
    extraction procedures. The apples treated with the unlabelled compound
    were analyzed by GLC to evaluate the changes in residue levels of the
    parent compound and its O-dealkylated transformation product
    1-(2,4-dichlorophenyl)-2-imidazol-1-ylethanol (T824 or R 14821)*
    during storage. The extraction method removed 93.0  5.6% of the total
    imazalil residue. During prolonged storage the residues of imazalil
    parent compound hardly declined, remaining in the range of
    1.75-2.0mg/kg. The metabolite R 14821 was found only in the samples
    taken after 4 months storage. Radio-HPLC revealed only the presence of
    the parent compound and the dealkylated metabolite, the latter only in
    amounts <3% of the total extractable residue. From the GLC and HPLC
    analyses it maybe concluded that under the prevailing storage
    conditions (low temperature, absence of light, lowered oxygen partial
    pressure), hardly any transformation of imazalil occurs. In addition,
    there was some evidence the fungicide was not lost from the treated
    fruit by volatilization.

              

    *    Identified in the 1977 and 1980 evaluations as -
         (2,4-dichlorophenyl)-1H-imidazole-1-ethanol.

         Table 7 shows the mass balance, as determined by radio-HPLC
    analysis, of 12C-imazalil residues in apples at various intervals
    after a post-harvest dip in 500 mg/l imazalil.

    Table 7.  Composition of imazalil residues in dipped apples

                                                                

                                    % of total 14C
                                                                
    Interval, months        Parent compound      R 14821
                                                                

    0                             97.6             2.4
    1                             98.4             1.6
    2                             97.0             2.9
    4                             97.9             2.1
                                                                

    METHODS OF RESIDUE ANALYSIS

         A GLC method especially designed for the analysis of residues
    from post-harvest uses on citrus fruits (Wynants 1977) was described
    in the 1977 evaluation. The method has been improved in several
    particulars, especially with regard to the efficiency of the
    extraction procedures, and it could be adapted for residue analysis on
    other commodities including pome fruit and fruiting vegetables such as
    cucumbers, melons, tomatoes and peppers.

         The method originally designed for the residue analysis of citrus
    fruit was not suitable for potatoes because the aqueous solvents
    extracted starch which formed intractable emulsions. Specific GLC
    methods for the residue analysis of potatoes have been developed
    (Wynants, 1979; Cayley et al., 1981). A recently developed method
    for potatoes (Janssen, 1983) uses GLC with a nitrogen-phosphorus
    thermionic detector and an internal standard: 
    [1-2-(2,4-dichlorophenyl)heptyll]-1H-imidazole mononitrate. A
    recovery of at least 90% was obtained. Woestenborghs et al (1982a,
    1982b) developed GLC methods for determining total extractable
    residues of imazalil and the O-dealkylated metabolite. The method is
    based on the improved extraction of imazalil and its metabolite from
    citrus fruits and their products, and conversion of the O-dealkylated
    metabolite to its trimethylsilyl derivative. Imazalil and the
    derivatized metabolite are determined by GLC with an electron-capture
    detector over a linear dynamic range equivalent to 0.005-20mg/kg. No
    internal standard is used.

         In view of the minor importance of the O-dealkylated metabolite
    in the residue arising from post-harvest uses, the methods of choice
    which are suitable or can be adapted for regulatory purposes are the
    GLC methods described in the first part of this section which
    determine only the parent compound.

    NATIONAL MAXIMUM RESIDUE LIMITS

         The following national MRLs were brought to the notice of the
    1984 JMPR.  The limits are expressed in mg/kg of the parent compound.

                                                                                                     
                                                      MRL, mg/kg
                                                                                                 
    Country                           Bananas             Citrus
    (date MRL established         Whole     Pulp      Whole     Pulp      Other commodities
                                                                                                 

    Australia                     -         -         5         -         Pome fruit        5

    Belgium                       2         0.2       5         0.1       Strawberries      2
    (Feb. 1982)                                                           Cucurbits         0.3
                                                                          Cereals           0.05

    Canada                        -         0.1       5         -

    Denmark                       2         0.2       5         0.1

    Finland                       2         0.2       3         0.2

    France                        2         0.2       5         0.1       Cucurbits         2
                                                                          Seed Potatoes     2

    Fed. Republic of              2         0.2       5         0.1       Cucumbers         2
    Germany (1982)                                                        Pumpkins          2
                                                                          Cereals           0.05

    Ireland                       -         -         5         -

    Israel                        -         -         5         -

    The Netherlands               2                   5                   Fruiting          0.5
    (March 1984)                                                          vegetables
                                                                          (including
                                                                           eggplant,
                                                                           cucumbers,
                                                                           gherkins,
                                                                           melons,
                                                                           tomatoes)
                                                                          Cereals           0.05
                                                                          Meat, milk        0.05
                                                                          Other food
                                                                           commodities      0.05

    New Zealand                   -         -         5         -

    Norway                        2         0.2       5         0.1
                                                                                                 

                                                                                                 
                                                        MRL, mg/kg
                                                                                                 
    Country                           Bananas             Citrus
    (date MRL established         Whole     Pulp      Whole     Pulp      Other commodities
                                                                                                 

    South Africa                  -         -         5         -         Cucurbits         0.5

    Spain                         -         -         2         -

    Sweden                        2         0.2       5         0.1

    Switzerland                   2         0.2       5         0.1

    USA                           3         0.2       10        -         Citrus oil,
                                                                          citrus pulp
                                                                          (dried)           25.0
                                                                          Wheat, barley,
                                                                          cotton seed       0.05
                                                                          Wheat and
                                                                          barley straw      2.0
                                                                                                 
    

    APPRAISAL

         The meeting reviewed information on residue levels of imazalil
    from supervised trials of post-harvest uses on apples, pears,
    persimmons (kaki-persimmon) cucumbers, melons, tomatoes and peppers.

         The fungicide, which is used against storage decay caused by
    various fungi, is applied as a dip, drench or spray or mixed in
    water-soluble vegetable waxes, The formulations used for the
    post-harvest treatments are WP 75%, EC 200 g/l, LS 100 g/l and
    technical imazalil (about 95%). Additional information was obtained on
    the metabolism of imazalil in plants. The residues on apples during
    storage under good storage conditions (low temperature, absence of
    light) consisted mainly of the parent compound. The only metabolite
    identified on apples after four months storage was O-dealkylated
    imazalil in small quantities (<3%).

         Information was provided on improvements to the methods of
    analysis referred to in the 1977 and 1980 evaluations and on new
    methods allowing simultaneous analysis of the parent compound and its
    main metabolite, O-dealkylated imazalil. Taking into account that the
    residue during storage for four weeks or longer consist almost
    entirely of imazalil, the meeting concluded that the present
    definition of the residue in terms of the parent compound only should
    be retained. Available GLC methods with EC detection which determine
    the parent compound only are suitable or can be adapted for regulatory
    purposes.

    RECOMMENDATIONS

         The meeting examined residue data from supervised trials
    reflecting current good storage or good agricultural practices and
    estimated maximum residue levels which are recommended as temporary
    MRLs. The limit for cucumbers replaces the existing level of 0.5 mg/kg
    which did not accommodate post-harvest uses. The limits refer to
    imazalil only.

                                                                       

    Commodity           MRL (mg/kg)     Pre-harvest interval on 
                                        which levels are based (days)
                                                                       

    Pome fruit              5                -    )
    Persimmons (kaki                              )
    persimmon)              2                -    )
    Cucumbers               5                -    )
    Melons                  5                -    ) From post-
    Peppers                 5                -    ) harvest
    Tomatoes                2                -    ) uses
    Potatoes 1              5                -    )
    Raspberries             2                7    )
    Strawberries            2                3-7  )
                                                                       

    1  The product is at present authorized for use only on seed 
       potatoes in three countries. These potatoes are used to some 
       extent as food or feed.


    REFERENCES

    1.   Residues resulting from supervised trials

         All references to supervised trials are unpublished reports
    provided to the 1984 JMPR by Janssen Pharmaceutica N.V., Beerse,
    Belgium

    Adato, I. Imazalil residues in apples. Variety Grand Alexander 1979.
    1980      Report of Residue Laboratory, Plant Protection Dept., State
              of Israel

    Adato, I. Results of residue analysis on bell peppers and melons.
    1983      Letter of Dr. I. Adato, Plant Protection Division, Ministry.
              of Agriculture, Israel, to AGAN Chemical Manufacturers Ltd.,
              Israel. Dec. 1983

    AGAN. Imazalil residues in Persimmons. Report of AGAN Chemical
    1979/80   Manufacturers Ltd., Israel

    Analchem (Australia). Analysis for residues of Imazalil in dipped
    1983      pears. Residue analysis Report AC 799/P3. Analchem
              Consultants Pty, Ltd. N.S.W., Australia

    Brogdex. Imazalil residues on tomatoes, report of Broydex Cy,
    1983      California, to Janssen Pharmaceutica, February 1983

    Carag, A. Analysis of Imazalil on tomatoes, bell peppers and
    1982      cucumbers. Report Project 273-1. Pennwalt Corporation,
              U.S.A.

    Cayley, R., Hide, G.A. and Tillotson, Y. The determination of Imazalil
    1981      on potatoes and its use in controlling potato storage
              diseases. Pestic. Sci. 12 103-109

    Clark, R.J. Determination of Imazalil residues in cucumbers and
    1978      raspberries. Report P527-26/1 1978. Hazleton Laboratories,
              Europe

    Clark, R.J. Determination of Imazalil residues in cucumbers and
    1980      raspberries. Reports 2285-26/3 and 4, 1980. Hazleton
              Laboratories, Europe

    Dharia, P., and Carag, G. Decay control and residue analysis of
    1983      Imazalil on cantaloupes. Report Project 273-17. Penwalt
              Corporation, U.S.A.

    Hamilton, J.F. Determination of Imazalil and T-824 residues in apples,
    1983a     Rutgers test. Report Project 82261. Biodynamics, Inc. East
              Millstone, New Jersey, U.S.A.

    Hamilton, J.F. Determination of Imazalil and T-824 residues in
    1983b     apples, Michigan test. Report Project 82261. Biojaynamics,
              Inc. East Millstone, New Jersey, U.S.A.

    Janssen Pharmaceutica. Imazalil/T824 residue levels in apples and
    1983-84   pears. Report of Janssen Pharmaceutica, December 1983 and
              Addendum January 1984.

    King, J.R., Latham, W.G.H. and Spalding, D.H. Gas chromatographic
    1982      analysis of Imazalil in peppers. Unpublished report,
              Subtropical Horticulture Res. Sta. Florida; U.S. Dept. of
              Agriculture, Agriculture Research Service

    Nordisk Alhali. Imazalil residues in apples, Cox Orange testing
    1982      Alanap, Sweden. Report of Janssen Pharmaceutica

    Woestenborghs, R., and van Leemput, L. Residue levels of Imazalil
    1984      during storage of potatoes, treated with 15g a.i. per ton,
              Internal report, Janssen Pharmaceutica

    Wynants, J. Determination of Imazalil in seed potatoes. Internal
    1979a     report of Janssen Pharmaceutica on La Quinoline trials

    Wynants, J. Determination of Imazalil in seed potatoes. Internal
    1979b     report of Janssen Pharmaceutica on trials by Schering,
              France

    2.   Fate of residues

    Van Leemput, L., Ruelens, P., Swysen, E., Hendricks, Michielsen, L.,
    1984      Woestenborghs, E., and Heykants, J. On the fate of Imazalil
              (R3979) on Golden Delicious apples during a controlled
              atmosphere storage for up to four months. Unpublished report
              R23979/L6. Janssen Research Products Information Service,
              Janssen Pharmaceutica N.V., Beerse, Belgium

    3.   Methods of residue analysis

    Cayley, R., Hide, G.A. and Tillotson, Y. The Determination of Imazalil
    1981      on potatoes and its use in controlling potato storage
              diseases. Pestic. Sci. 12 103-109

    Janssen Pharmaceutica. Determination of Imazalil (R23979) in potatoes.
    1983      Unpublished report St-GC 83-37, R23979 potatoes of Janssen
              Pharmaceutica N.V., Beerse, Belgium

    Woestenborghs, R., Michielsen, L. and Heylants, J. A gas-liquid
    1982a     chromatographic method for determining total regulable
              residues of Imazalil in citrus fruit and citrus by-products.
              Unpublished report R 23979/30. Janssen Research Products
              Information Service, Janssen Pharmaceutica N.V., Beerse,
              Belgium

    Woestenborghs, R., Michielsen, L., Meuldermans, W., and Heykants. A
    1982b     gas-liquid chromatographic method for determining total
              regulable residues of Imazalil in citrus fruit and citrus
              by-products: validation and application to a residue study
              of Imazalil in citrus fruit. Unpublished report R 23979/29.
              Janssen Research Products Information Service, Janssen
              Pharmaceutica N.V., Beerse, Belgium

    Wynants, J. Chromatographic assay methods of Imazalil in citrus fruit.
    1977      Proc. Int. Soc. Citriculture 3 1107-1113

    Wynants, J. Chromatographic assay methods of Imazalil in potatoes.
    1979      Med. Fac. Landbouww., Rijksuniv., Gent. 44 (2) 913-926


    See Also:
       Toxicological Abbreviations
       Imazalil (ICSC)
       Imazalil (Pesticide residues in food: 1977 evaluations)
       Imazalil (Pesticide residues in food: 1980 evaluations)
       Imazalil (Pesticide residues in food: 1984 evaluations)
       Imazalil (Pesticide residues in food: 1985 evaluations Part II Toxicology)
       Imazalil (Pesticide residues in food: 1986 evaluations Part II Toxicology)
       Imazalil (Pesticide residues in food: 1991 evaluations Part II Toxicology)
       Imazalil (JMPR Evaluations 2000 Part II Toxicological)
       Imazalil (JMPR Evaluations 2001 Part II Toxicological)
       Imazalil (JMPR Evaluations 2005 Part II Toxicological)