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    PHOSALONE                                  JMPR 1972

    IDENTITY

    Chemical name

         O,O-diethyl-S-[6-chloro-1,3 benzoxazol-2(3H)-onyl-methyl]
         phosphorodithioate

    Synonyms

         11,974 R.P., R.P. 11,974, bensophos

    Structural formula

    CHEMICAL STRUCTURE 1


    Other information on identity and properties

         Physical state:     non-hygroscopic crystalline solid

         Colour:             white

         Odour:              alliaceous

         Melting point:      45 - 48°C

         Solubility:         in water at 20°C is about 0.01 g/l, in
                             methanol and ethanol about 200 g/l, in other
                             organic solvents (acetone, acetonitrile,
                             benzene, chloroform, cyclohexanone, dioxane,
                             ethyl acetate, methylene chloride, methyl-
                             thylketone, toluene, xylene) about 1 000 g/l

         Stability:          of phosalone and its formulations, good

         Purity:             the technical product contains 93% active
                             ingredient

         Formulations:       wettable powders and emulsifiable
                             concentrates.

    EVALUATION FOR ACCEPTABLE DAILY INTAKE

    BIOCHEMICAL ASPECTS

    Absorption, distribution and excretion

    Phosalone is rapidly absorbed and excreted by mice following oral
    administration. Within 24 hours, less than 1% phosalone residues were
    found in the body (Desmoras and Fournel, 1968).

    Biotransformation

    Phosalone, an organophosphorus ester, exhibiting a weak potential for
    inhibiting cholinesterase, is converted to a more potent oxygen
    analogue. This analogue is 2-3 times more active as an inhibitory
    agent than phosalone, especially to serum cholinesterase
    (Rhône-Poulenc, 1968b).

    The metabolic fate of phosalone appears to follow a pattern typical of
    phosphorodithioate esters, i.e., oxidation to the phosphate,
    hydrolysis and conjugation of the leaving group and elimination, as
    shown in Figure 1.

    The major conjugate in plants has been described as the glucose
    conjugate of the benzoxazol moiety (1-[6-chloro-1,3-benzoxazol-
    (3H)-onyl] glucopyranose). This metabolite has an acute toxicity in
    mice of greater than 4 gm/kg (Rhône-Poulenc, 1968a).

    TOXICOLOGICAL STUDIES

    Special studies on metabolites

    Acute toxicity studies in rats and mice show the oxygen analogue of
    phosalone to be 2-3 times more toxic than phosalone (see Table 1).

    TABLE 1

    Acute toxicity of the oxygen analogue of phosalone

                        LD50 (mg/kg)

         Sex            Rats      Mice

         M              36        35

         F              20        40

         (Rhône-Poulenc, 1968b; Desmoras et al., 1963)


    FIGURE 1

    Special studies on neurotoxicity

    Adult White Leghorn hens (ten per group) were fed phosalone at levels
    of 0, 50, 163 and 500 ppm in the diet for 45 days. Another group was
    fed tri-o-cresyl phosphate (TOCP) at 500 ppm. Phosalone at 163 and 500
    ppm reduced egg production. No clinical or histological evidence of
    paralysis or demyelination was observed. TOCP dietary exposure
    resulted in signs of slight paralysis and evidence of minor central
    and peripheral nerve degeneration, as determined histologically
    (Woodard et al., 1966a).

    A group of Rhode Island Red Hens (ten birds) was administered
    phosalone subcutaneously at a dose of 350 mg/kg initially and after
    three weeks. The birds were administered atropine and P2S to protect
    against cholinergic stimulation. Mipafox (16 mg/kg) was administered
    subcutaneously as a positive control to four hens. No clinical or
    histological evidence in spinal cord or sciatic nerve of delayed
    neurotoxicity was evident with phosalone. Mipafox paralyzed all hens
    and induced demyelination in spinal cord or sciatic nerve (Heath
    et al., 1967).

    Special studies on potentiation

    Phosalone, in combination with other anticholinesterase agents, was
    examined for possible potentiation effects by administration of up to
    one-half of the oral LD50 of each material. Disulfaton potentiated
    the acute effects of phosalone. The toxicity of malathion and
    coumaphos was potentiated to a lesser extent, while potentiation did
    not occur with 15 other compounds, including: carbophenothion,
    demeton, disyston, diazinon, trichlorfon, azinphos-methyl, dioxathion,
    EPN, ethion, mevinphos, parathion-methyl, fenchlorfos, shradan,
    merphos and carbaryl (Scott and Beliles, 1965b).

    Special studies on reproduction

    Three groups of rats (20 females and 10 males per group) were fed
    phosalone at 0, 25 and 50 ppm in the diet and subjected to a standard
    two-litter, three-generation reproduction study. There were no effects
    on reproduction and lactation indices noted in this study which were
    attributed to phosalone (Jones et al., 1967a).

    Special studies on teratogenicity

    Teratogenicity tests were conducted with phosalone in chick embryos
    and rabbits. Doses of 0.2, 0.6 and 1.8 mg/egg were given to chick
    embryos. Doses of 2, 6 and 18 mg/kg daily were given orally to
    pregnant rabbits from day 6 to 16 of gestation. Thalidomide (100 mg/kg
    p.o./day) was the positive control in the rabbit study. No
    significantly greater incidence of total malformations due to
    phosalone were noted in either chick embryos or rabbits (Julou, 1969).

    Acute toxicity

    The acute toxicity of phosalone has been studied in animals. A summary
    of results of these studies is given in Table 2.

    TABLE 2  Acute toxicity of phosalone in various animal species
                                                                             

                                  LD50
    Species          Route        (mg/kg)        Reference
                                                                             

    Dog              oral         >1 600         Cookrell et al., 1965

    Rat     (F)      oral         153-207        Scott and Beliles, 1965a

            (M)      oral         125            Fournel et al., 1968

            (F)      oral         90             Ibid.

    Mouse            oral         320            Rivett and Davies, 1966

            (M)      oral         118            Fournel et al., 1968

            (F)      oral         93             Ibid.

    Chicken          SC           350            Heath et al., 1967
                                                                             

    Signs of poisoning following acute administration of phosalone are the
    same as for the other organophosphorus esters and include tremors,
    lacrimation and eventually convulsions and death. Signs of poisoning
    were evident within 10 to 20 minutes.

    An LC50 value of 64 mg/l was calculated following inhalation exposure
    of rats (male and female) to phosalone, for one hour at various doses,
    having a 3µ particle size (Beliles, 1966). A single dermal application
    to the shaved backs of rabbits at doses up to 2 000 mg/kg of a
    formulation (equivalent to a dose of phosalone at approximately 800
    mg/kg) for 24 hours resulted in no toxicity, but a mild erythema was
    noted at 2 000 mg/kg (Horn et al., 1965).

    Antidotal studies with rats and mice showed that both atropine and
    P2S are effective antidotes to the acute toxic signs of poisoning
    following oral administration of phosalone. P2S was apparently more
    effective than atropine, although in both cases multiple applications
    of antidotal material was suggested to be optimal (Rivett and Davies,
    1966).

    Short-term studies

    Rabbit

    Groups of rabbits (5 males and 5 females per group) were administered
    phosalone dermally to intact or abraded skin for three weeks, five
    days per week, at dosage levels of 1 ml of an emulsifiable
    concentrate, 0.05 ml of the E.C. (a dilution of the concentrate) and 1
    ml of a control E.C. with no phosalone. Weight loss, signs of toxicity
    and death, as well as significant cholinesterase depression, were
    apparent with both phosalone treatments to abraded skin. The rabbits
    treated with 1 ml of emulsifiable concentrate had a lower liver
    glycogen level, and both treated groups incurred renal congestion in
    animals with abraded skin. Dermal irritation was evident in all
    animals, and gross and histopathological examination showed no effects
    on other tissues examined (Woodard et al., 1966b).

    Dog

    Four groups of dogs (four males and four females per group) were fed
    phosalone in the diet for two years at levels of 0, 100, 200, and
    1 000 ppm. Effects on cholinesterases were evident at all dose levels
    throughout the study. Plasma cholinesterase was depressed at all
    feeding levels; RBC cholinesterase was depressed at 200 and 1 000 ppm,
    and brain cholinesterase was depressed at 1 000 ppm. One dog fed 1 000
    ppm (female) died at 93 weeks, and several others at this level
    exhibited fasciculations, nervousness and laboured respiration.
    Reduced body-weight was noted in both sexes at 1 000 ppm and in males
    at 200 ppm. Soft stools containing mucous and blood were observed for
    each treated group, with considerably more frequency at 1 000 ppm.
    This effect began to occur at the 100 ppm level after 53 weeks. ECG
    changes included an increased T-wave amplitude at 1 000 ppm, which was
    more apparent during the second year of study. Increased SGPT and SAP
    activity were observed at 1 000 ppm.

    Organ to body-weight ratios suggested that at 1 000 ppm the liver of
    both sexes and adrenals and thyroid of females were enlarged.
    Histological changes observed at all feeding levels were seen as
    increased basophilic granules in the myofibrillar cytoplasm in smooth
    muscle of the small intestine. These effects were less obvious as the
    dose decreased. Vacuolation of the smooth muscle cells of the small
    intestine was seen only at 1 000 ppm (Donoso et al., 1967).

    Three groups of dogs (four males and four females per group) were fed
    phosalone in the diet for 19 weeks at levels of 7.5, 15 and 25 ppm. In
    addition, at weeks 14 -19 disyston at 1 ppm was added to the diet of
    all animals. No effects on behaviour, growth, clinical chemistry,
    urinalysis, biochemistry or cholinesterase activity were noted in this
    study which were attributed to phosalone. Histological examination of
    the small intestine revealed no abnormalities (Jones et al., 1967b).

    Groups of dogs (four males and four females per group) were fed
    phosalone in the diet, at levels of 0, 12.5, 25 and 37.5 ppm for one
    month. Plasma cholinesterase activity was reduced at 37.5 ppm. In all
    dogs at 25 and 37.5 ppm, and in one dog at 12.5 ppm, a pink-mauve
    colouration of the mucosa of the bladder was noted although it was not
    observed in any other experiment performed in dogs. No effects were
    observed on growth, food consumption or RBC and brain cholinesterase
    activity (Noel et al., 1970).

    Five groups of calves were fed phosalone in the diet for ten weeks at
    levels of O, 20, 50, 80 and 160 ppm. No significant effects
    attributable to phosalone were observed on growth, behaviour, food
    consumption, hematology and cholinesterase activity (Woodard et al.,
    1967a).

    Long-term studies

    Rat

    Four groups of rats (30 males and 30 females per group) were fed
    phosalone in the diet for two years at levels of 0, 25, 50 and 250
    ppm. Effects attributable to phosalone were observed only on plasma
    cholinesterase, which was depressed at 50 ppm but not at 25 ppm. No
    other effects of treatment, either gross, histopathological or
    clinical, were noted at any of the dose levels studied (Woodard
    et al., 1967b).

    COMMENT

    Phosalone is rapidly absorbed, metabolized and excreted by rodents.

    Phosalone has been shown to have no effect on rat reproduction, is not
    teratogenic in chick or rat and is not neurotoxic to chickens. The
    acute toxic effect in rodents was potentiated with several
    organo-phosphates, particularly disyston.

    Two-year feeding studies in rats and dogs indicate no-effect levels
    (based on cholinesterase depression) of 25 ppm for both species.
    Bladder discolouration in dogs was reported in a short-term study, but
    longer studies did not confirm this observation.

    Observations in man are very limited.

    TOXICOLOGICAL EVALUATION

    Level causing no toxicological effect

         Rat:      25 ppm in the diet, equivalent to 1.25 mg/kg
                   body-weight
         Dog:      25 ppm in the diet, equivalent to 0.625 mg/kg
                   body-weight

    ESTIMATE FOR ACCEPTABLE DAILY INTAKE FOR MAN

         0 - 0.006 mg/kg body-weight

    RESIDUES IN FOOD AND THEIR EVALUATION

    USE PATTERN

    Phosalone is a non-systemic insecticide and acaricide active by
    contact and ingestion. It is officially approved for use in many
    countries on a wide variety of crops, and is practically nontoxic to
    bees.

    Pre-harvest treatments

    Phosalone is recommended in a number of countries to control a wide
    range of insects and mites on fruit, rape, sugar beet, potato,
    alfalfa, cotton, vegetables, grapes, tea and ornamental crops.

    Recommended rates of application vary in different countries from 0.4
    to 1.2 kg a.i./ha (0.04-0.06% a.i. with high volume sprays at
    1 000 - 2 000 l/ha). The recommended interval between two treatments
    is, in most countries, two to three weeks and in Canada ten days. The
    safety period in the treatment of orchard crops is in Canada, 1 - 7
    days; in Great Britain, 3 weeks; in France, 2 weeks; in Switzerland, 3
    weeks; in U.S.A., 1 week.

    Other uses

    Phosalone is used against ectoparasites of animals in some countries.

    RESIDUES RESULTING FROM SUPERVISED TRIALS

    The residue data from supervised trials are given in Table 3. These
    are from treatments made in Australia, Canada, France, Great Britain,
    New Zealand, South Africa and U.S.A. (Rhône-Poulenc, 1967-1971; May
    and Baker Ltd., 1967-1969).

    FATE OF RESIDUES

    General comments

    Studies on the behaviour of phosalone in animals, plants and soil have
    shown that phosalone has good stability (generally active against
    pests for 15 to 18 days) on plants, but in animals it is rapidly
    degraded to nontoxic products; decomposition is also rapid in soil.

    In animals

    Phosalone is rapidly degraded in animals. One half of the dose
    disappears after oral administration in four to six hours and the rest
    in 24 hours.

    Phosalone may be hydrolysed to nontoxic derivatives or oxidized to the
    oxo-derivative, which is responsible for inhibition of
    cholinesterases. The oxo-derivative, less stable than phosalone, is
    practically never detected, except in the liver where it may be found
    in minute quantities.

    When beef cattle and sheep were administered levels of 10, 30 and 100
    ppm in feed, traces of phosalone were found in fat and liver only at
    the feeding level of 100 ppm (Rhodia Inc., 1967a). No phosalone
    residues were found in milk of dairy cattle at any of the feeding
    levels of 100, 50 or 25 ppm (Rhodia Inc., 1967b; Woodard Research
    Corporation, 1967c).

    In plants

    Degradation of phosalone in plants is shown in Figure 2 (Desmoras
    et al., 1968a). The half-life of the residues in different plants is
    shown in Table 4. Half-lives vary from 2 to 20 days with application
    rates of 0.6 - 1.2 kg a.i./ha. The oxon derivative of phosalone is
    found, but its amount has been less than 10% of the total amount of
    the parent compound.

    In soil

    Degradation of phosalone in soils is shown in Figure 3. The half-life
    of phosalone in soils was found to be about a week. No accumulation of
    phosalone seems to occur in soils.


    
    TABLE 3  Summary of phosalone residue, data from different trials

                                                                                                                               

                                                                                                   Residuee of phosalone
    Crop           Country        Application      Treatments      Preharvest      Number of
                                  (kg/ha or        (no.)           interval        analyses        Range              Mean
                                     %)                            days                            (ppm)              (ppm)
                                                                                                                               

    Alfalfa        France         0.9              1               13              4               4 - 6              5

                                  0.9              1               20              4               1.7 - 2.9          2.2

                    U.S.A.        1.7              1               20-27           10              1.4 - 11.6         5.2

                                  1.7              1               11-14           4               24.5 - 37.0        30.6

                                  0.8-1.1          1               14              10              2.2 - 12.6         7.8

                                  0.8-1.1          1               20-23           20              0.8 - 7.6          3.3

    Apple          Australia      2.0              5-8             17-29           22              0.9 - 3.5          1.5

                   France         0.4- 0.6         4-7             16-28           20              0.75- z.6          1.5

                                  0.4-0.8          7               28              35              0.9 - 3.8          2.3

                                  1.3-1.5          3-4             14              24              0.9 - 2.9          1.8

                                  0.6              1-8             14-33           24              c.4 - x.0          0.7

                                  0.06%            7-8             21              8               2.1 - 3.6          2.9

                                  "                7               36-64           20              1.3 - 2.4          1.7

                                  "                7               75              4               0.9 - 1.0          1.0

                   England        0.46-0.69        2-3             59-70           3               0.05-0.49          0.2

    TABLE 3  (Cont'd.)

                                                                                                                               

                                                                                                   Residuee of phosalone
    Crop           Country        Application      Treatments      Preharvest      Number of
                                  (kg/ha or        (no.)           interval        analyses        Range              Mean
                                     %)                            days                            (ppm)              (ppm)
                                                                                                                               

                   New Zealand    0.056-0.09%      7-8             22-32           14              0.89-6.2           2.8

                   South Africa   0.03%            6-7             39-54           36              0.43-2.3           1.1

                                  "                5-7             66-84           36              0.36-1.0           0.7

                   U.S.A.         0.06%            5               22-36           6               2.2-5.3            4.6

    Beets          France         0.4-0.6          1               1               8               0.19-1.67          0.6

                                  "                1               3               8               0.20-1.35          0.4

    Cabbage                       0.4-0.6          1               1               4               4.1 -8.3           6.4

                                  "                2               1               4               0.6 -2.8           1.7

                                  "                6               1               4               0.3 -1.3           0.6

                   U.S.A.         0.06-0.12%       1               7-8             4               -                  <0.1

                                  0.12%            5               26              2               -                  <0.1

    Broccoli                      0.06%            2               7               2               -                  0.6

    Brussels
    sprouts                       0.06%            6               14              2               -                  0.7

    Cherry         Canada         0.03-0.04%       4               8               4               0.8 -4.9           2.8

                   U.S.A.         0.06%            4               21              2               -                  0.1

    TABLE 3  (Cont'd.)

                                                                                                                               

                                                                                                   Residuee of phosalone
    Crop           Country        Application      Treatments      Preharvest      Number of
                                  (kg/ha or        (no.)           interval        analyses        Range              Mean
                                     %)                            days                            (ppm)              (ppm)
                                                                                                                               

                   France         0.06%            1               8-18            4               0.3 -0.4           0.4

    Chestnut       U.S.A.         2-3              1-2             14-78           6               -                  <0.1

    Citrus fruit   "              2.5              1               14              18              -                  <0.1

    Cotton         France         1                6-13            13-14           12              <0.1 -0.9          0.5

                                  0.5-4            8-12            34-57           12              0.1 -1.6           0.8

    Cucumber       U.S.A.         0.06%            3               7-28            6               -                  0.1

                   France         0.6-1.2          1               10              8               0.01-0.04          0.02

    Grape          U.S.A.         1                1-3             28-43           8               1.8 - 2.4          2.0

                                  1.8-3.6          1               14              4               0.5 -0.9           0.7

                                  1                3               59              2               -                  0.9

                                  7.2              1               35              2               -                  1.3

                   South Africa   0.032-0.037%     3               41              12              0.4 -2.0           1.1

                                  0.032-0.037%     3               61              12              0.08-1.0           0.3

                                  0.032-0.037%     3               73              12              0.05-0.46          0.2

                   Canada         0.03-0.06%       5               14              12              1.8 - 4.7          3.0

    TABLE 3  (Cont'd.)

                                                                                                                               

                                                                                                   Residuee of phosalone
    Crop           Country        Application      Treatments      Preharvest      Number of
                                  (kg/ha or        (no.)           interval        analyses        Range              Mean
                                     %)                            days                            (ppm)              (ppm)
                                                                                                                               

                   France         0.06%            1               8               4               -                  0.3

                                  0.6              1               70              4               -                  0.4

    Hops           U.S.A.         1-1.2            2               28              8               1.2 - 1.7          1.51
                                                                                                                      <0.12

    Lettuce        U.S.A.         0.12%            5               7               2               -                  2.8

                                  "                5               26              2               -                  0.6

                   France         0.4-0.6          1               6               6               1.6 - 3.7          2.7

    Pea            U.S.A.         0.06%            1               49              2               -                  0.1

                   France         0.4-0.6          1               1               8               1.3 - 2.8          2.1

                                  "                1               2               8               0.5 -0.95          0.6

                                  "                1               13              8               0.05-0.2           0.12

    Peach          Canada         0.03-0.045%      5               8               4               1.1 - 2.2          1.9

                   U.S.A.         0.06%            5               40              2               -                  0.9

                   Australia      2.0              3-5             37-61           20              0.3 - 2.9          1.5

                   France         0.06%            1               7-14            4               0.7 - 1.9          1.4

    TABLE 3  (Cont'd.)

                                                                                                                               

                                                                                                   Residuee of phosalone
    Crop           Country        Application      Treatments      Preharvest      Number of
                                  (kg/ha or        (no.)           interval        analyses        Range              Mean
                                     %)                            days                            (ppm)              (ppm)
                                                                                                                               

    Pear           Australia      0.85             3-5             18-30           8               0.6 - 2.0          1.2

                   South Africa   0.03%            5-6             26-32           48              0.25- 1.8          0.7

                   France         0.06%            5               13              8               0.2 - 0.4          0.3

                   U.S.A.         0.06%            1-7             38-63           6               0.1 - 0.5          0.3

    Pecan          "              0.56             3-8             60-66           4               -                  <0.1

                   "              0.84             1               198             2               -                  <0.1

                   "              4.76             5               95              2               -                  <0.1

    Plum           Canada         0.03-0.045%      5               16              8               1.3 - 4.1          2.2

                   U.S.A.         0.06%            1               45-59           4               -                  1.3

                   England        0.03%            1-3             11-26           16              0.22- 1.8          0.7

    Potato         U.S.A.         0.06%            1-7             7-54            6               -                  <0.1

                   Australia      0.06%            9               1               24              -                  <0.02

                   France         0.4-0.6          1               7-9             6               -                  <0.05

    Rape seed      "              1-2.4            3               77              8               -                  <0.1

                   Denmark        0.7-2.05         1               27              16              -                  <0.1

    TABLE 3  (Cont'd.)

                                                                                                                               

                                                                                                   Residuee of phosalone
    Crop           Country        Application      Treatments      Preharvest      Number of
                                  (kg/ha or        (no.)           interval        analyses        Range              Mean
                                     %)                            days                            (ppm)              (ppm)
                                                                                                                               

    Sorghum        U.S.A.         1                2               108             4               -                  0.2

    Strawberry     "              0.06%            1               4-10            8               0.3 - 0.9          0.6

                   England        0.6              2               26              6               0.04-0.08          0.07

    Tomato         U.S.A.         0.6-0.12         1-4             14-15           6               <0.1 -0.6          0.3

                   France         0.4 -0.6         1               1               8               0.30-0.7           0.48

                                  0.4 -0.6         1               3               8               0.15-0.7           0.23

    Wheat          "              0.6              1               25-44           6               <0.05-1            0.3
                                                                                                                               

    1  fresh
    2  dried 3 days
    


    FIGURE 2

    FIGURE 3

    TABLE 4  Half-lives of phosalone residues in growing plants

                                                                      

    Crop                     Application rate              Half-life
                             (kg a.i./ha)                  (days)
                                                                      

    Alfalfa                  0.9 - 1.2                     4 - 10

    Apple                    0.3 - 5.4                     7 - 15

    Cabbage                  0.6 - 2.4                     2 - 5

    Cotton                   7.2 - 13.8                    4 - 6

    Cherry                   3.6                           4 - 10

    Grape                    0.6 - 1.2                     7 - 17

    Lettuce                  0.6 - 1.2                     3 - 8

    Peach                    0.5 - 3.0                     7 - 20

    Pear                     0.6 - 0.9                     8 - 15

    Plum                     5.4                           11 - 17

    Strawberry               0.6                           4 - 8
                                                                      

    In storage and processing

    There is no reliable data on the fate of phosalone in storage and
    processing of foodstuffs.

    METHODS OF RESIDUE ANALYSIS

    Desmoras et al. (1968d) have described procedures for the analysis
    of technical phosalone and its formulated products, and of residues in
    crops, vegetable oils and soil. A colorimetric method is based on
    hydrolysis to diethyldithiophosphoric acid followed by formation of
    the cupric complex. The preferred procedures are gas chromatography
    using catharometer detection and an ester as an internal standard for
    macro-analysis and electron capture detection for residue
    determinations; the use of a phosphorus sensitive thermionic detector
    gave poorer sensitivity. The outlines of the schemes for vegetable
    sample preparation are shown in Figures 4 and 5, the extracts being
    suitable for colorimetry gas chromatography or for a bioassay
    procedure using Daphnia or mosquito larvae. Variations are described
    for analysis of olives, olive oil and rape oil, while a simple
    extraction with acetone was suitable for soil samples. Method B with
    gas chromatographic end determination should be suitable for
    regulatory purposes.

    Other similar multiresidue GLC procedures should also be suitable for
    determining phosalone residues; that described by Abbott et al.
    (1970) has been found to be applicable to fatty samples.

    NATIONAL TOLERANCES

    Examples of national tolerances as reported to the Meeting are given
    in Table 5.

    TABLE 5

    Examples of national tolerances as reported to the meeting
                                                                   

    Country             Tolerance           Commodity
                        ppm
                                                                   

    Canada              10                  apples, pears
                        4                   peaches
                        6                   cherries

    South Africa        2                   apples, pears

    Switzerland         2                   grapes, fruit

    U.S.A.              10                  apples, pears, grapes
                        20                  raisins

    Australia           3                   peaches
                        2.5                 apples, pears
                        1                   fat of meat of sheep
                                                                   

    APPRAISAL

    Phosalone is a non-systemic dithiophosphate insecticide and acaricide
    used for pre-harvest control of a wide range of pests in agriculture,
    horticulture, ornamentals and vine-growing. It has limited use also
    against ectoparasites of animals. Its pesticidal activity on plants
    has a duration of two to three weeks, depending on the type of pest.
    The residues of potential toxicity are composed of the parent compound
    and, only to a minor extent, of the oxon derivative of phosalone. It
    is readily decomposed in animals and soils. Practically no
    contamination of animal tissues occurs as a result of feeding animals
    with fodder crops containing phosalone residues. Residue data of
    supervised trials on plants were available from many countries. No
    data were available on residues resulting from control of
    ectoparasites on animals, on fate of residues in food storage and
    processing, on levels of residues in foodstuffs moving in commerce or
    in total diets. Gas chromatographic procedures are the analytical
    methods of choice for use in regulatory laboratories. The limit of
    determination is at or about 0.1 ppm depending on the type of crop.

    FIGURE 4

    FIGURE 5

    RECOMMENDATIONS

    TOLERANCES

    Tolerances recommended apply to the parent compound. The time interval
    between application and harvest which has been used in determining the
    maximum residue limit is appropriate to the agricultural practices in
    numerous countries.

                                                                       

                                                 Time interval
                                                 between application
    Crop                               Ppm       and harvest (weeks)
                                                                       

    Apple, grape, peach, plum          5         2 - 3

    Cherry, pear, beetroots            2         2

    Hops (dried)                       2         4

    Citrus fruit, strawberry,
     tomato, cabbage, broccoli,
     Brussels sprouts, cucumber,
     lettuce, peas                     1         1 - 2

    Chestnut (shelled), pecan
     (shelled), potato, rapeseed       0.1*      2

    * at or about the limit of determination
                                                                       

    FURTHER WORK OR INFORMATION

    DESIRABLE

    1.   Studies on human exposure.

    2.   A study to determine dose levels causing no carboxylesterase
         (aliesterase) activity depression.

    3.   Effect of food storage and processing on residues.

    4.   Data on residues occurring in food commodities moving in
         commerce.

    5.   Nature and concentrations of impurities of the technical product.

    6.   Information on the use pattern of phosalone against ectoparasites
         of domestic animals and data on residues in animal products
         resulting from this use.

    REFERENCES

    Abbott, D.C., Crisp, S., Tarrant, K.R. and Tatton, J.O'G. (1970)
    Pesticide residues in the total diet in England and Wales 1966-67. III
    - Organophosphorus pesticide residues in the total diet. Pestic. Sci.,
    1: 10-13.

    Beliles, R.P. (1966) Phosalone (R.P. 11 974) - Safety evaluation by
    acute inhalation exposure of rats. Report Woodard Research
    Corporation, submitted by Rhône-Poulenc. (unpublished)

    Cockrell, K.O., Woodard, M.W. and Woodard, G. (1965) Phosalone R.P. 11
    974 - Acute oral LD50 in dogs. Report Woodard Research Corporation,
    submitted by Rhône-Poulenc. (unpublished)

    Desmoras, J., LaCroix, L. and Metivier, J. (1963) Pesticides of the
    benzoxazolone family. Phytiat.-Phytopharm., 12: 199-215.

    Desmoras, J. and Fournel, J. (1968) Studies on degradation of
    phosalone in mammals. Report Rhône-Poulenc. (unpublished)

    Desmoras, J., Fournell, J., Laurent, M., Sauli, M. and Terlain, B.
    (1968a) Etude de la vitesse de degradation de la phosalone dans de
    sal, les plantes et les animaux. Report no. 12964 Rhône-Poulenc.

    Desmoras, J., Laurent, M., Petrinko, P. and Buys, M. (1968b) Dosage de
    residus dans les cultures maraicheres. Report no. 13322 Rhône-Poulenc.

    Desmoras, J., Laurent, M., Sauli, M. and Terlain, B. (1968c) Etude du
    metabolisme de la phosalone dans les plantes et les sals. Report no.
    13093 Rhône-Poulenc.

    Desmoras, J., Luborg, F., Laurent, M., Bales, I.W. and Guardigli, A.
    (1968d) Application to the determination in the technical material.
    Phytiat.-Phytopharm. 4: 277-292.

    Desmoras, J., Laurent, M. and Buys, M. (1970a) Dosage de residus dans
    des pommes. Report no. 14899 Rhône-Poulenc.

    Desmoras, J., Laurent, M. and Buys, M. (1970b) Dosage de residus sur
    pommès en prorenance des Pays-bas. Report no. 14986 Rhône-Poulenc.

    Donoso, J., Woodard, M.W. and Woodard, G. (1967) Phosalone - Safety
    evaluation by repeated administration to dogs for 107 weeks. Report by
    Woodard Research Corporation, submitted by Rhône-Poulenc.
    (unpublished)

    Fournel, J., Julou, L. and Pasquet, J. (1968) Acute toxicity in mice
    and rats and in vivo anticholinesterase activity in rats. Report
    Rhône-Poulenc. (unpublished)

    Heath, S.A.B., Rivett, K.F. and Woolf, N. (1967) Test for
    neurotoxicity. Report May-Baker Ltd., submitted by Rhône-Poulenc.
    (unpublished)

    Horn, J.H., Woodard, M.W. and Woodard, G. (1965) Phosalone (R.P. 11
    974) acute dermal toxicity for rabbits. Report by Woodard Research
    Corporation, submitted by Rhône-Poulenc. (unpublished)

    Jones, M.E., Post, K.F., Scott, W.J., Woodard, M.W. and Woodard, G.
    (1967a) Three generation reproduction study in the rat. Report by
    Woodard Research Corporation, submitted by Rhône-Poulenc.
    (unpublished)

    Jones, M.E., Imming, R.J., Woodard, M.W. and Woodard, G. (1967b)
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    the compound disyston.

    Julou, L.  (1969) Study of the teratogenic activity of phosalone on
    chick embryo and rabbit. Report Rhône-Poulenc. (unpublished)

    May and Baker Ltd. (1967a) Report no. C. 263. (unpublished)

    May and Baker Ltd. (1967b) Report no. C. 274. (unpublished)

    May and Baker Ltd. (1967c) Report no. C. 277. (unpublished)

    May and Baker Ltd. (1968a) Report no. PRG./85. (unpublished)

    May and Baker Ltd. (1968b) Report no. PRG./88. (unpublished)

    May and Baker Ltd. (1968c) Report no. PRG./162. (unpublished)

    May and Baker Ltd. (1968d) Report no. PRG./171. (unpublished)

    May and Baker Ltd. (1968e) Report no. PRG./173. (unpublished)

    May and Baker Ltd. (1968f) Report no. PRG./310. (unpublished)

    May and Baker Ltd. (1969a) Report no. PRG./425. (unpublished)

    May and Baker Ltd. (1969b) Report no. PRG./534. (unpublished)

    Noel, P.R.B., Rivett, K.F., Osborne, G.E. and Street, A.E. (1970)
    Phosalone dietary intake in Beagle dogs for 4 weeks. Report by
    Huntingdon Research Centre, submitted by Rhône-Poulenc. (unpublished)

    Rhodia Inc. (1967a) Results for phosalone residue in tissues of beef
    cattle and sheep concerning blood plasma. (unpublished)

    Rhodia Inc. (1967b) Results for phosalone in milk of dairy
    cattle - Woodard Research Centre Project. (unpublished)

    Rhône-Poulenc. (1967) Report no. 12433. (unpublished)

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    (unpublished)
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    toxicity, and anticholinesterase activity in vitro. (unpublished)

    Rhône-Poulenc. (1968c) Report no. 13018. (unpublished)

    Rhône-Poulenc. (1969a) Report no. 13551. (unpublished)

    Rhône-Poulenc. (1969b) Report no. 13553. (unpublished)

    Rhône-Poulenc. (1970) Report no. 14356. (unpublished)

    Rhône-Poulenc. (1971a) Report no. 15209. (unpublished)

    Rhône-Poulenc. (1971b) Report no. 15210. (unpublished)

    Rhône-Poulenc. (undated) Zolone, phosalone (with 27 references
    concerning phosalone).

    Rivett, K.F. and Davies, V. (1966) Effects of antidotes against
    poisoning by phosalone. Report by May and Baker, submitted by
    Rhône-Poulenc. (unpublished)

    Scott, W.J. and Bililes, R.P. (1965a) Acute oral toxicity of phosalone
    (R.P. 11 974) formulation to rats. Report by Woodard Research
    Corporation, submitted by Rhône-Poulenc. (unpublished)

    Scott, W.J. and Beliles, R.P. (1965b) Potentiation studies in the rat
    with marketed pesticides. Report by Woodard Research Corporation,
    submitted by Rhône-Poulenc. (unpublished)

    Woodard, M.W., Cockrell, K.O. and Woodard, G. (1966a) Demyelination
    study in chickens. Report by Woodard Research Corporation, submitted
    by Rhône-Poulenc. (unpublished)

    Woodard, M.W., Cockrell, K.O. and Woodard, G. (1966b) Sub-acute dermal
    toxicity of phosalone for the rabbit. Report of Woodard Research
    Corporation, submitted by Rhône-Poulenc. (unpublished)

    Woodard, M.W., Imming, R.J., Thompson, W. and Woodard, G. (1967a)
    Phosalone, safety evaluation by oral administration to calves for 10
    weeks. Report by Woodard Research Corporation, submitted by
    Rhône-Poulenc. (unpublished)

    Woodard, M.W., Howard, D.J., Donoso, J. and Woodard, G. (1967b) Safety
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    (unpublished)

    Woodard Research Corporation. (1967c) Phosalone analysis of residue in
    milk of dairy cattle.
    


    See Also:
       Toxicological Abbreviations
       Phosalone (ICSC)
       Phosalone (WHO Pesticide Residues Series 5)
       Phosalone (Pesticide residues in food: 1976 evaluations)
       Phosalone (Pesticide residues in food: 1993 evaluations Part II Toxicology)
       Phosalone (Pesticide residues in food: 1997 evaluations Part II Toxicological & Environmental)
       Phosalone (JMPR Evaluations 2001 Part II Toxicological)