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    CYANOFENPHOS    JMPR 1975

    IDENTITY

    Chemical name

         O-4-cyanophenyl O-ethyl phenylphosphonothioate

    Synonyms

         SurecideR

         CYP, OMS-870, S-4087, Surazon

    Structural formula

    CHEMICAL STRUCTURE 1


    ther information on identity and properties

         Physical state:     pure compound, white crystalline solid.
                             Technical product, slightly yellowish solid
                             with characteristic odour

         Melting point:      83C

         Vapour pressure:    10 mm Hg at 225C

         Specific gravity:   D20   = 1.29
                              4

         Solubility:         practically insoluble in water, soluble in
                             ketones (acetone, methyl ethyl ketone, methyl
                             isobutyl ketone, cyclohexanone), hydrocarbons
                             (benzene, toluene, xylene,
                             methylnaphthalene), methylene dichloride,
                             chloroform, acetonitrile, dimethyl formamide,
                             ethyl cellosolve. Slightly soluble in
                             methanol, isopropanol, kerosene, soybean oil.

         Stability:          stable for two years under normal storage
                             conditions. Half-life values in aqueous
                             solutions at 60C and

                             pH 6.0    -    150 days
                             pH 8.0    -    227 days
                             pH 10.0   -    68 days

    The composition of the technical product is reported to be as follows.

         Active ingredient                                  92.0 - 95.0%

         O,O-diethyl phenylphosphonothioate                 3.0 - 5.0%

         O,O-di(4-cyanophenyl)phenylphosphonothioate        1.0 - 2.0%

         O-ethyl phenylphosphonochloridothioate             <0.2%

         O,S-diethyl phenylphosphonodithioate               <0.2%

         S-ethyl O-(4-cyanophenyl)phenylphosphonothioate    <0.5%

         4-cyanophenol                                      <0.3%

    EVALUATION FOR ACCEPTABLE DAILY INTAKE

    BIOCHEMICAL ASPECTS

         Sumitomo Chemical Company in their submission have abstracted a
    study on the absorption and metabolism of C14 labelled cyanofenphos
    in the mouse. This was taken from a private communication (S. Kato and
    J. Miyamoto, presented at T.R. commission of IUPAC Meeting in
    September 1974) which was not available for review. They did present
    data on the absorption and biodegradation patterns of O,O dimethyl
    O-(4-cyanophenyl) phosphorothiate in the rat (Wakimura and Miyamoto,
    1971) and of O-(4 bromo-2,5 dichlorophenyl) O-methyl phenylphosphonate
    (Leptophos) in mice and on cotton plants (Holmstead et al., 1973). The
    company has implied that cyanofenphos has similar absorption and
    biodegradation patterns as the above-mentioned compounds.

    TOXICOLOGICAL STUDIES

    Special studies on neurotoxicity

         Chicken

         Cyanofenphos was administered orally as a single dose of 100
    mg/kg/ bodyweight to eight white leghorn chickens (1-1.5 years of
    age). The birds were observed for three weeks. The same treatment was
    repeated and birds observed for a further three weeks. Atropine and
    2-PAM were used to protect the birds from acute intoxication. One bird
    died during first test period. Birds that survived through the two

    treatment periods did not exhibit delayed paralysis of the legs.
    Histopathologic examination of sciatic nerve and spinal cord did not
    reveal demyelination. A single dose of TOCP (400 mg/kg body weight)
    produced paralysis in legs after two weeks with degeneration and
    demyelination of the sciatic nerve.

         In a further study cyanofenphos was administered at daily doses
    of 2 and 4 mg/kg body weight six days a week for four weeks and
    observed for a further four weeks. Both groups exhibited anorexia, a
    decrease in spontaneous motor activity and in body weight gain. No
    paralysis was noted. No anomalies were observed in sciatic nerve and
    spinal cord on histopathologic examination (Kadota et al., 1972).

    Special studies on reproduction

         In a three-generation reproduction study (two litters per
    generation) eight male and 16 female rats received dietary
    concentrations of 0, 1, 3 and 10 ppm cyanofenphos during the first d
    generation. For the second and third generations those selected from
    the 1 ppm dietary groups the concentration of cyanofenphos in the diet
    was increased to 30 ppm. No treatment related effects were observed on
    body weight gain, survival or ophthalmic and pathological examinations
    in parental animals. However, reduced mating indices during third
    generation and lowered male and female fertility during second and
    third generation were consistently observed at 30 ppm. Pup viability
    was reduced at 30 ppm. No compound related effects were observed with
    respect to weanling weights, gross external observation or
    histopathological examination of F3b progeny (Smith et al., 1975).

    Special studies on teratogenicity

         Groups of pregnant rabbits received 0, 1.0, and 3.0 mg/kg body
    weight/day of cyanofenphos via gelatin capsule from day 6 through day
    18 of gestation. Animals were sacrificed at day 29 of gestation and
    pups removed by Caesarean section. No significant differences were
    found in total number of implantation sites, number of resorptions and
    number of live young. Body weights of foetuses were similar for
    treated groups and were comparable to control. Twenty-four hour
    survival was not affected. No visceral or skeletal abnormalities were
    noted. The results obtained with the positive control (thalidomide)
    demonstrated the susceptibility of this strain to a teratogenic agent
    (Ladd and Smith, 1973).

        Acute toxicity

    Technical compound (purity 92%)

                                                                                  

                                     LD50 mg/kg
    Species   Route     Solvent        M         F        Reference
                                                                                  

    mouse     oral      Tween 80     36        30         Kadota and Miyamoto, 1973

              S.C.      Tween 80     68        48         Kadota and Miyamoto, 1973

              I.P.      Tween 80     27.5      19         Kadota and Miyamoto, 1973

              Dermal    Tween 80     >1 000    >1 000     Kadota and Miyamoto, 1973


    rat       oral      Tween 80     89        32         Miyamoto and Kadota, 1972

              S.C.      Tween 80     200       50         Miyamoto and Kadota, 1972

                        Gum Arabic   1 120     380        Miyamoto and Kadota, 1972

              I.P.      Tween 80     141       30         Miyamoto and Kadota, 1972

              Dermal    peanut oil   >1 000    640        Miyamoto and Kadota, 1972


    hen       oral      Tween 80               60         Kadota et al., 1972
                                                                                  
    

         A single instillation of 0.05 ml suspension of cyanofenphos in
    Tween 80 was found to be irritating to the rabbit eye at 0.2% and
    above. At 1.0% eye closure, congestion of the conjunctiva and
    lacrimation were noted. No changes were observed in cornea,
    conjunctival reflex, corneal reflex and pupil diameter.

         When cyanofenphos suspension was instilled daily (six days a
    week) for four weeks at dosage levels of 0.2 and 1.0%, similar eye
    reactions were observed which did not appear to increase in intensity
    with time. Myosis was not observed (Kagoshima et al., 1972)

         Two groups of guinea pigs were sensitized by injecting
    intracutaneously 5% and 1% solutions of cyanofenphos in corn oil every
    other day for 20 days. Each animal was challenged with an
    intracutaneous injection of cyanofenphos in corn oil and a dermal
    application of this compound in acetone 14 days after last sensitizing
    dose. Local swelling was observed at injection site both on
    sensitizing and challenging the animals. No remarkable changes with
    dermal challenge (Koda et al., 1972).

    Short-term studies

         Dog

         Four groups of dogs (four male and four female/group) were fed 0,
    10, 30 and 100 ppm cyanofenphos in the diet for 12 months. Two male
    dogs at 100 ppm displayed a moderate ataxia of the hindquarters during
    the final month of testing. Growth, food consumption, mortality,
    haematology, blood chemistry, urinalysis, ophthalmologic examination,
    gross and histopathology revealed no compound related effect. Liver to
    body and brain weight ratio was increased in four of eight dogs at 100
    ppm. Plasma and red blood cell cholinesterase activities at 100 ppm
    were decreased when determined at one, three and nine months. Red
    blood cell cholinesterase was also reduced at 12 months. No inhibitory
    effect on brain cholinesterase was noted at any level (Marias et al.,
    1974).

         Cow

         Groups of four cows were fed diets containing 0, 5, 15 and 50 ppm
    cyanofenphos. On day 30 of treatment three cows/group were sacrificed,
    the remaining animal of each group was fed the control diet for a
    further 30 days. Milk, liver, kidney, muscle and fat were collected
    from each animal and analysed for residues.

         No adverse reactions due to the feeding of cyanofenphos were
    observed. Trace levels of cyanofenphos and its oxon metabolite were
    found only in milk and tissues of cows fed 50 ppm. Residue levels were
    below the limit of detection (<0.002 ppm) during the withdrawal
    period (Ladd and Winegender, 1975).

    Long-term studies

         Rat

         Groups of 60 rats (six weeks of age) were fed cyanofenphos at
    dietary levels of 0, 10, 30, 100 and 200 ppm in males and 0, 5, 15, 50
    and 100 ppm in females for 24 months. There was no apparent evidence
    of significant changes in general behaviour, mortality, body weight
    gain, food and water consumption, urinalysis, haematology, clinical
    biochemistry, organ to body weight ratio or gross and microscopic
    examination of tissues. Plasma, red blood cell and brain
    cholinesterase were depressed in males at 100 and 200 ppm and in
    females at 50 and 100 ppm (Kadota et al., 1974).

    COMMENTS

         Although data on the absorption, metabolism and excretion have
    been presented on two similar chemicals and reference made to data on
    cyanofenphos from a private communication, no metabolic data on
    cyanofenphos per se have been received.

         There were no teratogenic or neurotoxic effects observed with
    cyanofenphos. Reproductive effects were observed in both parental
    animal and progeny at 30 ppm. The no-effect level was 10 ppm. In a
    short-term (12 month) study with the dog the no-effect level was 30
    ppm in the diet based on plasma and erythrocyte cholinesterase
    activity. In a long-term study in the rat, the no-effect level for
    cholinesterase inhibition was 15 ppm. Based on the available
    information and considering the lack of metabolic data a temporary
    acceptable daily intake was allocated.

    TOXICOLOGICAL EVALUATION

    Level causing no toxicological effect

         Rat: 10 ppm in the diet equivalent to 0.5 mg/kg
         Dog: 30 ppm in the diet equivalent to 0.75 mg/kg

    Estimation of temporary acceptable daily intake

         0-0.005 mg/kg

    RESIDUES IN FOOD AND THEIR EVALUATION

    USE PATTERN

         Cyanofenphos is mainly applied against insect pests including
    Lepidoptera, Diptera, Orthoptera, Hemiptera and Coleoptera in field
    crops, fruits and vegetables. It is also applied for the control of
    insects affecting livestock such as blow flies, lice and ticks.

         The percentage of cyanofenphos used in different fields of
    application varies according to current pest situations. A rough
    estimate is 60% for field crops (rice, cotton, legumes, cereals), 20%
    for vegetable crops (crucifers, onions, cucurbits), 15% for pome
    fruit, stone fruit, citrus and tea, and 5% for veterinary uses.

         Approximate dosages and frequencies of application are shown in
    Table 1.

    TABLE 1. Dosages and frequencies of application of cyanofenphos

                                                                     

    Crop                      Dosage and frequency of application
                                                                     

    Rice                      0.25-0.75 kg a.i./ha, 2-4 times/season

    Pome and stone fruits     0.025-0.75 kg a.i./ha, 2-4 times/season

    Vegetables                0.25-0.75 kg a.i./ha, 2-5 times/season

    Tea                       0.5-1 kg a.i./ha, 1-3 times/season

    Cotton                    0.5-1 kg a.i./ha, 2-6 times/season

    Sheep                     0.02-0.05% by plunge dips, once a year
                              0.04-0.06% by shower dips, once a year
                                                                     


    RESIDUES RESULTING FROM SUPERVISED TRIALS

         Extensive data on residues resulting from supervised trials were
    available. Different countries have different patterns of consumption
    and usage of agricultural commodities, e.g. in some countries rice
    straw after harvest is used as a feed of farm animals. Table 2
    summarizes the residue levels which have been found when the product
    is used according to "good agricultural practice" in Japan (Sumitomo,
    1975).

    FATE OF RESIDUES

    In animals

         Following oral administration of cyanofenphos to dairy cows at
    dietary levels of 5, 15 and 50 ppm for 30 consecutive days, samples of
    muscle, fat, liver, kidney and milk were analysed to determine
    contents of cyanofenphos and cyanofenphos-oxon. In the tissue samples
    residue levels were highest in the fat and decreased in the order fat
    >> liver > kidney = muscle. Levels of cyanofenphos ranged from
    approximately 1 mg/kg in the fat to 0.012 mg/kg in the kidney and
    muscle in the highest dose group. The oxon levels ranged from
    approximately 0.08 mg/kg in fat to less than 0.0004 mg/kg in liver,
    kidney and muscle from the same group. Residues of cyanofenphos
    (<0.002-0.013 mg/kg) were also found in fat samples from the lower
    and middle dose groups and in liver samples from the middle group.


    
    TABLE 2.  Cyanofenphos residues resulting from supervised trials in Japan

                                                                                                                

                                 Rate of          Number of        Pre-harvest
                                 application      applications     interval            Residues
    Crop           Formulation   (kg a.i./ha)     per season       (days)              (mg/kg)
                                                                                                                

                                                                                   rough rice       straw

    Rice           EC            0.4, 0.5         2                59              0   0.002        2.26

                                 0.5              4                51              0   0.014        6.14

                                 0.6              2                45              0   0.034        0.546

                                 0.6              4                37              0   0.141        1.26

                                 0.5, 0.75        2                40              0   0.055        0.695

                                 0.75             4                31              0   0.196        4.86

                   Dust          0.6              1                47              0.011

                                 0.6              2                43-59           <0.002-0.010

                                 0.45, 0.6        2                47              0.005

                                 0.6              3                44-50           <0.002-0.023

                                 0.6              4                32              0.021

                                                                   42              0.012

                                 0.45, 0.6        2-2              37              0.002

    TABLE 2. (Cont'd.)

                                                                                                                

                                 Rate of          Number of        Pre-harvest
                                 application      applications     interval            Residues
    Crop           Formulation   (kg a.i./ha)     per season       (days)              (mg/kg)
                                                                                                                

                                                                                   green            pod

    Soybean        EC            0.5              2                7               0.142, 0.228     6.00, 6.571

                                                  3                7               0.402            8.978

                                                  4                7               0.156            8.50

                                                                                   dried bean

                                                  2                34-50           0.075, 0.186

                                                  3                50              0.108

                                                  4                34              0.214


                                                                                   fresh            peel

    Peach          EC            0.75             2                3 (4 samples)   0.004-0.028      6.3-31.3

                                                  2                7      "        0.006-0.009      7.8-27.0

                                                  2                14     "        0.004-0.012      6.8-13.7

                                                  4                3      "        0.007-0.038      7.2-39.4

                                                  4                7      "        0.005-0.014      6.4-32.1

                                                  4                14     "        0.004-0.014      4.8-18.4

    TABLE 2. (Cont'd.)

                                                                                                                

                                 Rate of          Number of        Pre-harvest
                                 application      applications     interval            Residues
    Crop           Formulation   (kg a.i./ha)     per season       (days)              (mg/kg)
                                                                                                                

    Cabbage        EC            0.375            2                28              0.002

                                                  2                35              <0.001

                                                  2                42              <0.001

                                                  3                14              0.123

                                                  3                21              0.002

                                                  3                28              0.001

                                 0.5              2                7               0.186

                                                  2                14              0.092

                                                  2                21              0.028

                                                  4                7               0.258

                                                  4                14              0.108

                                                  4                21              0.026

                                 0.75             2                7               1.45

                                                  2                14              0.902

                                                  2                20              0.721

    TABLE 2. (Cont'd.)

                                                                                                                

                                 Rate of          Number of        Pre-harvest
                                 application      applications     interval            Residues
    Crop           Formulation   (kg a.i./ha)     per season       (days)              (mg/kg)
                                                                                                                

    Cabbage                                       2                28              0.020
      (continued)
                                                  2                35              0.015

                                                  2                42              0.010

                                                  3                14              0.050, 0.056

                                                  3                21              0.004, 0.008

                                                  3                28              0.001, 0.002

                                 0.5, 0.75        2 + 2            7               2.02

                                                  2 + 2            14              2.02

                                                  2 + 2            20              1.24

                                 1.5              3                14              0.083

                                                  3                21              0.008

                                                  3                28              0.002

    Onion          D             1.35             1                189-234         <0.002


    Cucumber       D             0.9              1                39-42           <0.001

    TABLE 2. (Cont'd.)

                                                                                                                

                                 Rate of          Number of        Pre-harvest
                                 application      applications     interval            Residues
    Crop           Formulation   (kg a.i./ha)     per season       (days)              (mg/kg)
                                                                                                                

    Ginger         EC            0.7              3                45-52           0.004, 0.008
    (root)
                                                  6                  "             0.006, 0.012

    Tea            EC            1                1                7               48.6, 49.2
    (steamed)
                                                  1                14              23.0, 27.1

                                                  1                21              4.35, 8.40

                                                  1                27-28           1.19, 7.29

    Apple          EC            1.5              2                45-48           0.412, 0.444

                                                  2                60-63           0.292, 0.306

                                                  2                77-79           0.288, 0.316

                                                  3                30-33           0.590, 0.711

                                                  3                45-48           0.332, 0.636

                                                  3                61-64           0.522, 0.580

    TABLE 2. (Cont'd.)

                                                                                                                

                                 Rate of          Number of        Pre-harvest
                                 application      applications     interval            Residues
    Crop           Formulation   (kg a.i./ha)     per season       (days)              (mg/kg)
                                                                                                                

                                                                                   root             leaves

    Radish         Dust          1.8              1                65              <0.002           <0.002

                                                  1                65              <0.002           <0.002

                   Granules      0.3              1                24              0.001-0.157

                                                  1                65-66           <0.001-0.007

                                 0.6              1                24              0.002-0.080

                                                  1                65-66           <0.001-0.001
                                                                                                                
    

         160 milk samples were analysed for residues of cyanofenphos and
    cyanofenphos-oxon during the 30-day feeding period. Residues of
    cyanofenphos were detected only in samples from the highest dose
    group. The maximum residue found was 0.4 mg/kg on the second and
    fourth sampling day. Cyanofenphos-oxon residues reached a peak of
    0.061 mg/kg on the fourth sampling day which dropped to about 0.020
    mg/kg throughout the remainder of the 30 days (Jenkins et al., 1975).

    In plants

         The metabolism of cyanofenphos-14C (CN) by bifoliate bean plants
    (phaseolus vulgaris, L.) grown in a greenhouse was studied by Chiba et
    al. (1973). Little translocation was found when cyanofenphos-14C was
    applied to the leaf. It was not taken up from water into the aerial
    parts of the plant and most of the radioactivity was in the roots in
    the form of intact cyanofenphos. Cyanofenphos seems to be fairly
    persistent under these experimental conditions. Approximately 50% of
    the compound initially applied remained in the plant samples two weeks
    after foliar application.

         The persistence of cyanofenphos was also observed in several
    other crops including rice grains, vegetables and fruits (Sumitomo,
    1975). 4-cyanophenol and desethyl cyanofenphos-oxon were detected as
    metabolites by TLC. However, neither cyanofenphos-oxon nor desethyl
    cyanofenphos was positively identified.

    In soils

         Cyanofenphos-14C (CN) was fairly persistent when incorporated
    into soil (volcanic ash loam) at 10 mg/kg. 53% of the initial
    radioactivity remained after three weeks. In comparison, when
    Cyanox-14C (the corresponding O,O-dimethyl phosphorothionate ester of
    p-cyanophenol) was incorporated into the soil at the same level, only
    6% of the radioactivity remained after two weeks. No degradation
    products in soils were identified (Chiba et al., 1973).

    Photodecomposition

         Aqueous solutions containing 7 mg/l of cyanofenphos-14C (CN)
    were exposed to bright sunlight for 20 days, and the resultant
    photoproducts were examined. After 20 days exposure, 78.3% of the
    recovered radioactivity was intact cyanofenphos, and by extrapolation,
    the half-life is presumed to be about 50 days. The predominant
    photoproducts were cyanofenphos-oxon and p-cyanophenol, amounting to
    7.8% and 4.8% respectively. These two products tend to increase on
    longer irradiation. A non-radioactive photoproduct was identified as
    ethyl phenylphosphonic acid. The following compounds were not
    detected: cyanofenphos-S-isomer, desethyl-cyanofenphos,
    desethyl-cyanofenphos-oxon, radioactive carbon dioxide and hydrogen
    cyanide.

         Unlike aqueous solutions, cyanofenphos deposits on silica gel
    chromatoplates underwent rapid photodecomposition with a half-life of
    two days, yielding mainly cyanofenphos-oxon and p-cyanophenol. A trace
    of 2-hydroxy-5-cyanobenzoic acid was detected. This compound as well
    as p-cyanobenzoic acid was also produced, in small quantities, by
    irradiation of an acetone solution of cyanofenphos or p-cyanophenol
    with UV light. Several pesticides and antioxidants such as rotenone,
    phenazine, phenazine-N-oxide, and 2,5-tert-butylhydroquinone
    accelerate the photolysis of cyanofenphos, with accompanying increase
    of the oxon and p-cyanophenol, while beta-carotene, xanthophyll and
    chlorophyll are inactive (Mikami et al., 1975).

    METHODS OF RESIDUE ANALYSIS

         Residues of cyanofenphos are determined by gas-liquid
    chromatography with either flame thermionic or with flame photometric
    detection (Sumitomo Chemical Co. Ltd, 1975). The solvents and
    techniques used to extract cyanofenphos from samples are similar to
    those used for fenitrothion (FAO/WHO, 1975b). Samples with a high
    water content such as fruits and vegetables are blended with polar
    solvents (acetone, acetonitrile, methanol or
    acetonitrile-methanol-water mixtures). Samples with a high content of
    fat or oil such as fresh soybeans are extracted with acetone followed
    by chloroform. Dry samples such as rice grains are extracted with
    benzene. A suitable extraction scheme is shown in Figure 1.

         Sumitomo Chemical Co. Ltd (1975) have reported recoveries of
    cyanofenphos added to several crops (Table 3). Gas chromatography was
    on a column containing a mixture of 10% DC-200 and 20% OV-1 on
    silanized Chromosorb W with the column, injector and detector at
    240C. The carrier gas was helium and EPN was used as an internal
    standard. The limit of detection was about 0.001 mg/kg with a
    potassium bromide thermionic detector.

    TABLE 3. Recoveries of cyanofenphos added to crop samples

                                                                      

         Crop                Cyanofenphos added, mg/kg     Recovery, %
                                                                      

    Cabbages                          0.2                     97.2
    Sugar beets                       0.02                    85.2
    Radishes (root)                   0.02                    92.3
    Soybeans                          0.02                    93.1
    Rice grains                       0.1                     99.3
                                                                      


         TLC on silica gel with benzene as the developing solvent is used
    to confirm identity and if necessary as a final clean-up step.
    Cyanofenphos (Rf about 0.4) is visualized under UV light or by
    spraying with palladium chloride solution.

    FIGURE 1

    APPRAISAL

         Cyanofenphos has a wide insecticidal activity, and since it is
    moderately persistent it offers a possible alternative to the
    persistent organochlorine compounds. Considerations of cost limit its
    use for this purpose at present, however.

         Although the persistence of cyanofenphos can lead to residues in
    and on crops at harvest, the potentially toxic metabolite
    cyanofenphos-oxon has not been found in plants.

         The translocation of cyanofenphos in plants is very limited.
    Although radio tracer studies have been undertaken, the identities of
    the metabolites in plants have not been fully elucidated. Studies with
    the cyanofenphos molecule labelled in other positions might provide a
    more detailed understanding of the metabolic pathways. In particular
    the fate of the P-C ring bond in plants and animals remains to be
    fully determined for cyanofenphos and some other phosphonates.

         No information was available on the tendency to partition into
    vegetable oils and animal fats. Information is needed on the
    distribution of residues in rice and their fate in processing and
    cooking.

         Residue data from many supervised trials conducted in Japan were
    made available and were considered sufficient to make recommendations
    for temporary maximum residue limits on several commodities.

    RECOMMENDATIONS

         The following temporary maximum residue limits are based on the
    determination of the parent compound only.

    TEMPORARY MAXIMUM RESIDUE LIMITS
                                                                        

                                                 Pre-harvest intervals
                                      Limit,     on which recommendations
    Commodity                         mg/kg      are based, days
                                                                        

    Cabbage                           2                     7
    Peaches                           1                    14
    Soybean (fresh, without pods)     0.5                   7
    Soybean, dry                      0.5                  30
    Radishes (roots)                  0.2                  21
    Rice (hulled)                     0.2                  30
    Cucumber                          0.05*                40
    Ginger                            0.05*                40
    Onions                            0.05*               150
                                                                        

    *  At or about the limit of determination.

    FURTHER WORK OR INFORMATION

    REQUIRED (by 30 June 1978)

    1.   Data on absorption, metabolism and excretion in at least one
         mammalian species.

    2.   Studies to identify and investigate toxicity of plant
         metabolites.

    3.   Distribution of residues in rice and their fate during processing
         and cooking.

    4.   Information on residues in dry green and dry manufactured
         (fermented) tea.

    5.   Studies on residues in sheep following dipping and spraying.

    6.   Results of ongoing studies on the feeding of poultry to determine
         the fate of residues in tissues and eggs.

    7.   Further information on the fate in cabbage during processing and
         cooking.

    DESIRABLE

    1.   Observations in man including cholinesterase studies.

    2.   Appropriate mutagenic study.

    3.   A further long-term study.

    4.   Information from trials in countries other than Japan.

    5.   Studies to determine whether cyanofenphos residues can be
         determined by current multiresidue methods.

    REFERENCES

    Chiba, M., Kato, S. and Yamamoto, I. (1973) Metabolism of Cyanox and
    Surecide in plant and degradation in soil. Unpublished report
    submitted from Tokyo University of Agriculture, Tokyo, Japan. Private
    Communication to Sumitomo Chemical Co.  Presented by J. Miyamoto at
    Commission on Terminal Residues, IUPAC Meeting, 1974.

    Holmstead, R. L., Fukuto, T. R. and March, R. B. (1973) The Metabolism
    of O-(4-Bromo-2,5-Dichlorophenyl) O-Methyl Phenylphosphonothioate
    (Leptophos) in White Mice and on Cotton Plants. Archives of
    Environmental Contamination and Toxicology, 1:133-147.

    Jenkins, D. H., Kinoshita, F. K. and Keplinger, M. L. (1975) Meat and
    milk residue study with Surecide in dairy cattle. Unpublished report
    from Industrial BIOTEST Laboratories, U.S.A., submitted by Sumitomo
    Chemical Co. Ltd., Osaka.

    Kadota, T., Kagoshima, M., Miyamota, J. and Nobuyuki, I. (1972) Acute
    Toxicity and Delayed Neurotoxicity of B-4087 (Surecide) in Hens.
    Unpublished report from the Research Department, Sumitomo, submitted
    to the World Health organization by Sumitomo Chemical Co., Japan.

    Kadota, T. and Miyamota, J. (1973) Acute Toxicity of Surecide in Mice.
    Unpublished report from the Research Department, Sumitomo, submitted
    to the World Health Organization by Sumitomo Chemical Co., Japan.

    Kadota, T., Hosokawa, T., Kohda, H., Miyamoto, J. and Itoh, N. (1974)
    Two year Chronic Toxicity Study with Surecide in Rats. Unpublished
    report from the Research Department, Sumitomo, submitted to the World
    Health Organization by Sumitomo Chemical Co., Japan.

    Kagoshima, M., Kadota, T. and Miyamota, J. (1972) Acute and Subacute
    Eye Irritation Tests of Surecide in Rabbits. Unpublished report from
    the Research Department, Sumitomo, submitted to the World Health
    Organization by Sumitomo Chemical Co., Japan.

    Koda, H., Kagoshima, M., Kadota, T. and Miyamota, J. (1972) Skin
    Sensitization Test of Surecide in Guinea Pigs. Unpublished report from
    the Research Department, Sumitomo, submitted to the World Health
    organization by Sumitomo Chemical Co., Japan.

    Ladd, R. and Smith, P. S. (1973) Teratogenic Study with Surecide in
    Albino Rabbits. Unpublished report from Industrial Bio-Test
    Laboratories submitted to the World Health Organization by Sumitomo
    Chemical Co., Japan.

    Ladd, R. and Winegender, R. J. (1975) Meat and Milk Residue Study with
    Surecide in Dairy Cattle. Unpublished report from Industrial Bio-Test
    Laboratories submitted to the World Health Organization by Sumitomo
    Chemical Co., Japan.

    Marias, A., Burtner, B. R., Kennedy, G. L. and Keplinger, M. L. (1974)
    12 Month Chronic Oral Toxicity Study with Surecide Technical in Beagle
    Dogs. Unpublished report from Industrial Bio-Test Laboratories
    submitted to the World Health Organization by Sumitomo Chemical Co.,
    Japan.

    Mikami, N., Ohkawa, H. and Miyamoto, J. (1975) Photo-decomposition of
    Surecide (O-ethyl O-(4-cyanophenyl) phenylphosphonothioate).
    Unpublished report submitted by Sumitomo Chemical Co. Ltd, Osaka.
    Presented by Miyamoto, J. at TR Commission of IUPAC Meeting in 1975.

    Miyamota, J. and Kadota, T. (1972) Comparative Acute Toxicological
    Studies with Surecide and EPN in Rats. Unpublished report from the
    Research Department, Sumitomo, submitted to the World Health
    Organization by Sumitomo Chemical Co., Japan.

    Smith, S., Kennedy, G. L., Kinoshita, F. K. and Keplinger, M. L.
    (1975) Three Generation Reproduction Study with Surecide in Albino
    Rats. Unpublished report from Industrial Bio-Test Laboratories,
    submitted to the World Health Organization by Sumitomo Chemical Co.,
    Japan.

    Sumitomo Chemical Co. Ltd (1975) Unpublished report.
    


    See Also:
       Toxicological Abbreviations
       Cyanofenphos (Pesticide residues in food: 1980 evaluations)
       Cyanofenphos (Pesticide residues in food: 1982 evaluations)