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    BROMOPROPYLATE     JMPR 1973

    IDENTITY

    Chemical name

         isopropyl-4,4'-dibromobenzilate

    Synonyms

         NEORON(R), ACAROL(R)
         Ciba/Geigy GS-19851

    Structural formula

    CHEMICAL STRUCTURE 1


    Other information on properties

    Physical state:          White crystalline powder

    Melting point:           77°C

    Vapour pressure:         5.5 x 10-7 mm Hg at 20°C
                             5.25 x 10-3mm Hg at 100°C
    Density:                 1.59 g/cm3 at 20°C

    Solubility:              <0.5 ppm in water at
                             20°C, soluble in organic solvents

    Stability:               Fairly stable in neutral or
                             slightly acid media;
                             half-life periods in aqueous 10%
                             methanol at PH O (IN HCI) 50 days;
                             at PH 6-7 (water) >3 years;
                             at pH 9 (0.05 M borax buffer)
                             15 days;

    Purity:
    (technical material)     Minimum 88% isopropyl-4,4-dibromobenzilate
                             Maximum 12% by-products of manufacture
                             isopropyl-4-bromobenzoate
                             isopropyl ether of isopropyl-4,4
                             dibromobenzilate
                             isopropyl-4-bromobenzilate
                             isopropyl-alpha,alpha-bis (4 bromophenyl)
                             acetate
                             toluene
                             Details of concentration of individual
                             impurities filed with FAO as
                             confidential information were
                             considered by the meeting.

    EVALUATION FOR ACCEPTABLE DAILY INTAKE

    Biochemical aspects

    Absorption, distribution and excretion

         Two male and two female rats were each administered by gavage 1.6
    mg 14C-labelled bromopropylate. Expired CO2, urine and faeces were
    collected for the next 120 hours in periods of 24 hours following
    which blood and other tissues were taken for analysis. Less than 0.2%
    of activity was found in respired CO2.  In males, 90% of activity was
    found in faeces and 6% in urine while in females 55% appeared in
    faeces and 33% in urine. About 75% activity was eliminated in 48 hours
    but after 120 hours 2.6% (males) and 1.5% (females) of the
    administered dose remained in tissues, mainly kidneys, liver and fat.
    (Cassidy and Min, 1968).

         One cow received 0.33 mg/kg/day of 14C-labelled bromopropylate
    in the diet for five days. After a further 13 days without treatment
    the animal was killed. In the 20 days 94.9% of the administered
    activity was recovered, 0.96% in the milk, 20.5% in the urine and
    73.4% in the faeces. No activity was detectable in tissues other than
    adipose tissue which contained 0.06-0.17 ppm at the time of autopsy
    (Murchison, 1968; Cassidy et al., 1968).

    Biodegradation

         Only the parent compound was detected in the adipose tissue and
    the milk of a cow which had received 0.33 mg/kg/day of 14C-labelled
    bromopropylate for five days. Most of the activity found in the faeces
    was the parent compound as shown by analysis of the first
    post-treatment day sample which contained 92% parent compound, the


    remainder being unidentified metabolites. The majority of activity in
    urine consisted of 4,4'-dibromobenzilic acid and a more polar
    unidentified metabolite. Other possible metabolites,
    4,4'-dibromobenzohydrol, 4,4'-dibromobenzophenone and 4-bromobenzoic
    acid were not found (Cassidy et al., 1968). In the faeces of rats
    administered bromopropylate 60% of activity was parent compound and
    20% 4,4'-dibromobenzilic acid (Cassidy et al., 1968).

         Three groups of three beef calves were each fed diets containing
    0, 5 and 50 ppm bromopropylate. Fat biopsies were taken after two and
    eight weeks of feeding and one animal from each group was killed after
    four and six weeks. After 10 weeks feeding the remaining animal which
    had been fed on the 5 ppm diet was killed; the one on 50 ppm was
    maintained on control diet for a further two weeks before it was
    killed. After four, six and 10 weeks the 5 ppm diet produced
    respectively levels of 1.5, 1.5 and 2.8 ppm of bromopropylate in the
    fat. The 50 ppm diet produced fat levels of 7.3 ppm after four, and
    8.0 ppm after six weeks. After two weeks an control diet the
    concentration of bromopropylate in fat had fallen to 0.3 ppm. Muscle
    tissue contained low residues of unchanged bromopropylate while liver
    and kidneys also contained 4,4'-dibromobenzilic acid during the
    feeding period. (Cullen and Mattson, 1968; Fancher et al., 1968, b and
    c.)

    TOXICOLOGICAL STUDIES

    Special studies on reproduction

    Rat. Groups of 20 male and 20 female rats in the first generation
    and groups of 25 male and 25 female rats in the second and third
    generations were used in a three-generation test (two litters being
    produced in each generation) and fed on diets containing 0, 2.5 and 5
    ppm bromopropylate. In a second test, groups of 25 male and 25 female
    rats received diets containing 0, 30 and 100 ppm bromopropylate.
    Through out the tests no abnormalities attributable to bromopropylate
    were found in the reproductive physiology of male or female rats and
    there was no evidence of gross abnormalities in the offspring
    throughout the studies. The number of young in each litter and their
    growth and survival were normal. The weights of liver, kidneys and
    spleen were comparable with controls in the rats of the F 3b
    generation whose parents received 2.5 and 5 ppm diets while spleen and
    liver weights of F 3b young of parents fed on 30 and 100 ppm diets
    were slightly higher than controls. No histological abnormalities were
    found in these animals at any dosage level (Coulston, et al. 1970c;
    Coulston et al., 1971).

    Dog.  Groups of three male and three female dogs were fed on diets
    containing 0, 30 and 100 ppm bromopropylate in their diet. After an
    unstated time the females were mated with males of the same group. All
    matings resulted in pregnancy and delivery of normally sized litters.
    The only deformed pup was found in a control litter. All others were

    normal in appearance, behaviour and development. Increases in the body
    weight of the pups in most of the litters of groups receiving
    bromopropylate were similar to those of control pups. The reduced
    growth rate of one litter of the 100 ppm group was attributed to the
    results of poor maternal care (Coulston et al., 1970b;  Coulston and
    Benitz, 1972).

    Acute toxicity

         The results of tests to investigate the acute toxic action of the
    compound are summarized in Table 1.


    TABLE 1. THE ACUTE TOXICITY OF BROMOPROPYLATE

                                                                        

                                             LD50
    Species    Sex    Route   Purity         (mg/kg)    Reference
                                                                        

    Mouse      M      O       Tech           8 000      (Ueda and Kondo,
                                                         1968)

    Rat        M+F    O       Tech           >5 000     (Stenger, 1967)

    Rat        M+F    O       Formulation    6 000      (Drake, 1970)

    Rat               O       Formulation    >23 100    (Fencher et al.,
                                                         1968a and b)

                                                                        


    Short-term studies

    Rat.  Groups of 10 male and 10 female rats received 0, 40, 200, 1000
    and 5000 mg bromopropylate/kg bw by gavage as a suspension in 0.5%
    aqueous tragacanth on six days each week for four weeks. The highest
    dosage level produced polyuria throughout the 21 days before the
    animals were killed and for the first eight days pale mucoid faeces
    were produced. The rate of body weight gain and food intake were
    reduced in this and the 1000 and 200 mg/kg groups. Rats of the 5000
    mg/kg group developed a relative neutrophilia but the results of
    haematological analyses in all groups were normal. The absolute and
    relative liver weights were increased in the three highest dosage
    groups and cytoplasmic swelling and periportal infiltration were seen.
    Hepatic necrosis occurred at the highest dosage level. At the 40 mg/kg
    dosage level the one animal which died during the test showed similar
    abnormalities in the liver; others of the group appeared normal.
    (Paterson, 1967a).

         Groups of 12 male and 12 female rats were fed for 90 days on
    diets containing 0, 100, 300 and 1000 ppm bromopropylate. Another
    group received diet containing 3000 ppm for 55 days and 4000 ppm for a
    further 35 days. In the highest dosage level group the food intake and
    rate of weight gain were below normal and at autopsy the liver, kidney
    and testes weights were heavier than in controls relative to body
    weight, and loss of basophil material, pigmentation (possibly
    lipofuscin)  and fatty infiltration were present in hepatocytes. Mild
    to severe regressive changes were seen in testes on histological
    examination. At the 1000 ppm level food intake was slightly less than
    in controls although weight gain was similar. Testes were lighter than
    in controls and similar histological changes were seen in the liver.
    At the two lower levels smaller numbers of rats showed loss of
    basophil material and cytoplasmic swelling with focal vacuolation.
    These changes were considered to be physiological being attributed to
    SER hypertrophy, but no EM studies were carried out to confirm this.
    The results of haematological and blood biochemistry studies and of
    urine analyses were similar in all groups. (Paterson and Drake, 1967.)

    Dog.  A group of two male and two female dogs received orally, by
    capsule, lg/kg/bw/day of bromopropylate for 30 days. A second group
    received 2 g/kg/day for four days, then 0.5 g/kg for a further 26
    days. Diarrhoea and vomiting occurred in dogs of both groups. During
    the first week the food intake was decreased and body weight was lost
    or the gain in weight was below normal. The results of a
    haematological examination were normal. Determination of organ weights
    did not indicate any dose-related changes. In both groups serum
    transaminase and alkaline phosphatase levels were increased by
    treatment and cytoplasmic swelling and fine vacuolation of hepatocytes
    was found. No mature spermatoza were found in male animals but this
    may have been due to the age of the animals. (Paterson, 1967b.)

         Four groups of eight male and eight female dogs were fed for two
    years on diets containing 30, 100, 250 and 1000 ppm bromopropylate. A
    fifth group received 4000 ppm in the diet for three months.

         A group of 10 males and 10 females acted as controls. The highest
    dosage level produced light coloured soft stools after one week and
    semi-fluid stools thereafter. Food intake was reduced and weight was
    lost. Two dogs died (after four and six weeks) and two others were
    killed because they became cachetic. In these four animals increased
    serum alkaline phosphatase, diminished serum cholesterol and mild
    anaemia were found. Haemosiderosis of Kupfer cells, proximal tubular
    cells of the kidney, the spleen and the bone marrow, degenerative
    changes in the distal convoluted tubules of the kidney, hyperplasia of
    bone marrow and extramedullary haematopoiesis were seen in these
    animals at autopsy. In the other animals of the 4000 ppm group killed
    at three months, accumulation of haemosiderin in the macrophages of
    the spleen and bone marrow and in Kupfer cells was observed.
    Examination of liver by EM showed S.E.R. hypertrophy and an increase
    in numbers of lysosomes, many of which contained lamellar structures.
    Two male and two female animals were fed for nine months on control

    diets following three months on 4000 ppm diet. Stools returned to
    normal consistency within a week and weight was gained normally.
    Biochemical and haematological parameters also returned to normal in a
    short time; animals were indistinguishable from controls at the time
    of autopsy. The 1000 ppm diet also produced softening of stools.
    Although weight gain by males was normal, females failed to gain
    weight. Some females showed slight anaemia on some occasions. The
    microsomal enzymes, biphenyl hydroxylases, showed increased activity
    and this was associated with an increase in liver weight relative to
    body weight at six months and at two years (in females only). SER
    hypertrophy was marked at three months and numerous myelin bodies were
    also seen. Although at two years the SER hypertrophy was not different
    from controls, myelin bodies were still present.

         An increase in microsomal enzymes was found in the 250 ppm group
    together with an enlarged liver (relative to body weight) at six
    months but not at two years. No adverse effects were observed in dogs
    fed on 100 and 30 ppm diets (Coulston et al., 1970b).

    Long-term studies

    Rat. Groups of 50 male and 50 female rats were fed for two years on
    diets containing 0, 15, 30 and 100 ppm bromopropylate. Five male and
    five female rats from each group were killed after six months and one
    year and autopsies performed. No changes in appearance or behaviour
    occurred. Food consumption and weight gain were similar in test and
    control animals throughout the test and survival rates were similar
    for the first 18 months. Approximately half of these control female
    animals alive at 18 months survived to 24 months while only a third of
    test animals on 30 and 100 ppm levels survived over this period. No
    alterations attributable to bromopropylate were observed in the
    results of haematological examinations or serum analyses in test
    animals. No changes in organ weights of gross or microscopic
    abnormalities attributable to ingestion of the pesticide were observed
    in animals examined at any time. However, EM studies on the livers of
    animals of the 100 ppm group surviving two years showed slightly less
    glycogen, focal enlargement of intracrestal space in the mitochondria,
    focal dilatation of SER and more prominent lipid accumulations than
    livers of control animals. These differences were not considered to be
    significant pathological alterations in cell ultrastructure. The
    number of tumours and their location were similar in control and test
    groups (Coulston et al., 1970a).

    Comments

         Bromopropylate is absorbed rapidly and eliminated in both faeces
    and urine. Faeces contain a high proportion of parent compound while
    4,4'-dibromobenzilic acid and a more polar (unidentified) metabolite
    are found in urine. A larger proportion of ingested compound was found
    in the faeces of male than of female rats. Although the elimination of
    a single dose was not complete by 120 hours in rats and about 2% of

    the dose was detectable in tissues, mainly in the kidneys, liver and
    fat at that time, there was no evidence that bromopropylate or its
    metabolites are likely to accumulate in tissues.

         Studies in rats and dogs show no ill-effect on reproductive
    function and no teratogenic effect was seen in response to diets
    containing 100 ppm bromobenzilate. The no-effect level in a two-year
    rat study was 15 ppm in the diet. In female rats exposed to 30 or 100
    ppm survival rates were reduced, but only during the last few months
    of the test. Some abnormalities were observed in the EM appearance of
    hepatic cells of rats receiving 100 ppm bromopropylate but the
    toxicological significance of these is doubtful. Rats exposed to more
    than 100 ppm showed a reduced rate of weight gain, reduced food intake
    and increased weight of liver and kidneys. The increased liver weight
    found in dog studies was accompanied by SER hypertrophy and an
    increase in the activity of microsomal enzymes. Liver enlargement in
    rats was also associated with histological appearance suggestive of
    enzyme induction. Dietary levels of about 3000 ppm produced
    pigmentation and marked fatty infiltration of hepatocytes and
    degenerative changes in the kidneys and testes of rats. The no-effect
    level in a two-year dog study was 100 ppm in the diet. The two-year
    rat study did not indicate that bromopropylate has carcinogenic
    activity.

    TOXICOLOGICAL EVALUATION

    Level causing no toxicological effect

         Rat: 15 ppm in the diet equivalent to 0.75 mg/kg bw

         Dog: 100 ppm in the diet equivalent to 2.5 mg/kg bw

    Estimate of acceptable daily intake for man

         0-0.008 mg/kg bw.

    RESIDUES IN FOOD AND THEIR EVALUATION

    Use pattern

    Bromopropylate was first tested in the field for control of mites in
    1966. The product is officially approved or in the process of
    registration in the following countries:

              Australia      France         Portugal
              Austria        Iran           South Africa
              Belgium        Israel         Spain
              Bulgaria       Italy          Switzerland
              Chile          Japan          Turkey
              Cyprus         Netherlands    USSR
                                            Yugoslavia

         Commercial formulations are emulsifiable solutions containing 25%
    and 50% active ingredient.

    Pre-harvest treatments

         Use recommendations.

         Bromopropylate is a contact miticide effective against all stages
    of mites such as Eriophyidae (eriphyid mites), Tenuipalpidae
    (false spider mites) and Tetranychidae (spider mites) (Vial et al.,
    1971).

         Although the chemical does not have a pronounced ovicidal action,
    it displays some activity on the early egg development stages, Newly
    hatched larvae are killed by contact with the araricidal deposit on
    the foliage.

         Bromopropylate kills mites in all postembryonal stages, whether
    they are susceptible or resistant to chlorinated hydrocarbons and/or
    organic phosphate compounds (Westigard and Barry, 1970).

         The main fields of application are in pome fruit citrus,
    grapevines, hops and cotton. The recommended application rates in the
    various crops are given in the following table.

         The effective dosage rate per unit area depends on the amount of
    foliage and on the size of the plants being treated: consideration
    should be given to the foliage surface increase during the growing
    period of the developing crop. Normally only one treatment would be
    required if applied before mite populations build up and if climatic
    conditions were unfavourable to mites. Under some circumstances it is
    necessary to provide for a second treatment.

    Post-harvest treatment

         Bromopropylate is only recommended for application to growing
    crops.

    Other uses

         Bromopropylate is also used on ornamental plants (dosage rate:
    37.5-50 g ai/100 l).

    Residues resulting from supervised trials

         Pome fruits, stone fruits, grapevines, citrus, bananas,
    strawberries, vegetables, cotton, tea and hops were treated in field
    trials with the 25% and 50% ES formulations at recommended
    concentrations of 25-60 g ai/100 l spray mixture. Residues were
    determined by gas chromatography with an electron capture detector as
    well as with a microcoulometric detector. The limits of detection
    varied from 0.01-0.05 ppm. Data from residue trials conducted in

    Australia, Canada, Germany, India, Indonesia, Israel, Japan, South
    Africa, Switzerland and the United States of America are compiled in
    Table 1.


    TABLE 1. RECOMMENDED APPLICATION RATES OF BROMOPROPYLATE FOR
             VARIOUS CROPS
                                                                
    Crop                  g ai/100 l           g ai/ha
                                                                
    Pome fruit            37.5-50              500-750

    Stonefruit            37.5-50              500-750

    Citrus                37.5-50              500-750

    Grapevines            37.5-50

    Hops                  37.5-50

    Cotton                37.5-50              500-750

    Soybeans                                   500-750

    Vegetables                                 400-600

    Tea                   37.5
                                                                

    Fruits

         Bromopropylate is a non-systemic and non-penetrating acaricide.
    It remains on the peel and does not migrate into the pulp of the
    fruits.  Various experiments with labelled and non-labelled
    bromopropylate in apples, citrus and bananas showed clearly that the
    pulp of treated fruits contained none or only minute traces of
    residues.

         Higher dosages or multiple applications generally yield higher
    residues, i.e. the quantity of residues soon after application is
    proportional to the amount of active ingredient applied.

         The dissipation of residues is mainly due to weathering and
    growth dilution (Cassidy, 1967). Table 2 shows the residues of
    bromopropylate immediately and three weeks after treatment and the
    estimated half-life periods on different crops.

         It is most noticeable that the level and rate of disappearance of
    residues on distinctly different varieties of fruit are exceptionally
    uniform. There is adequate justification for extending the tolerance
    to include fruits on which there are only limited data.

    TABLE 2. RESIDUES OF BROMOPROPYLATE AT VARIOUS TIMES AFTER TREATMENT
             AND ESTIMATED HALF-LIFE PERIODS ON DIFFERENT CROPS

                                                                        
                       Average residues in ppm                 Half-life
    Crop           Immediately         Three weeks             period
                   after treatment     after treatment         (weeks)
                                                                        

    Apples         1.8                 1.0                     3-4

    Pears          0.7                 0.36                    3

    Plums          1.7                 0.75                    3

    Grapes         1.1                 0.70                    3

    Strawberries   8.3                 0.5                     1-2

    Citrus         1.8                 0.9                     3

    Hops           13-50               4.4-27.0                2

    Tea            > 20                -                       <1

                                                                        


    Vegetables

         Residues of bromopropylate in tomatoes and eggplants were 0.12
    ppm or less 7-21 days after a single treatment at normal use rates.

    Cotton

         Seed and fibres of cotton were analysed separately; in the seeds
    no residues could be detected three days after treatment of the plants
    with 50 g bromopropylate/100 l.

    Tea

         In trials in Indonesia each sample taken from tea plants on the
    first, fourth, seventh and ninth day after spraying was divided into
    two halves. Before residue analysis, one-half of each sample was
    submitted to the usual process of manufacture (made tea) consisting of
    withering, rolling, fermentation and firing of tea leaves; the second
    half of each sample was merely dried at 25°- 30°C (dried leaves).
    Residues of bromopropylate decreased rapidly on made tea as well as on
    dried tea (within nine days of application from levels of 22.5-55 ppm
    to levels of 0.15-2.5 ppm). The estimated half-life period is less
    than one week.

    Hops

         Generally, residue levels are higher in dried than in fresh hops
    due to concentration during the drying. Practically no evaporation of
    bromopropylate takes place during drying.

    Fate of residues

    In animals

         A cow received 14C-bromopropylate by capsule for five days at a
    rate of 0.33 mg/kg/day, corresponding to 9.7 ppm in feed. Within 20
    days the radio-activity recovered in faeces, urine and milk amounted
    to 73.4%, 20.5% and 0.66% respectively. After the last dose, the
    concentration of 14C-bromopropylate equivalents in milk approached
    0.09 ppm and declined rapidly reaching the limit of quantitative
    determination five days post treatment. Radio-activity showed
    corresponding behaviour indicating a level of 0.03 ppm at the end of
    the treatment period. Radio-activity was no longer detected after
    another four days.

         When the animal was killed, 20 days after treatment, only fat
    contained significant radio-activity averaging 0.13 ppm of
    bromopropylate equivalents. In all other tissues and organs (muscle,
    liver, kidney, heart, brain, ovary, spleen) radioactivity was below
    the limit of detection, i.e. 0.01 ppm (Cassidy et al., 1968).

         The compound was fed during 30 and 70 days to milk cows (Fancher
    et al., 1968d; Mattson et al., 1968) and to beef calves (Fancher et
    al., 1968c; Cullen and Mattson, 1968); and the residues followed up in
    milk, fat tissues, liver, kidney and muscle (see Table 3).

         The residues in milk were found to be proportional to the feeding
    levels of bromopropylate in the diet (Mattson et al., 1968) and did
    not exceed 0.1 ppm at the 5.3 ppm dosage rate. Residues are mainly
    found in the fatty tissue where they mounted to 2.8 ppm after 70 days
    at the 5 ppm feeding rate. Bromopropylate is, however, rapidly
    eliminated from fatty tissues: after two weeks following a 70-day
    feeding at 50 ppm, only 0.3 ppm of bromopropylate could be found. In
    muscle 0.19 ppm and 0.42 ppm bromopropylate were detected after
    feeding 70 days at 5 ppm and 28 days at 50 ppm, respectively. Again a
    rapid excretion of the compound was observed after cessation of
    administration (<0.04 ppm two weeks after feeding for 70 days at
    50 ppm).

         In liver and kidney, 4,4'-dibromobenzilic acid was found in
    addition to small amounts of unchanged bromopropylate. The presence of
    4,4'-dibromobenzilic acid indicated that these organs may be the site
    of hydrolysis of bromopropylate. The presence of 4,4'-dibromobenzilic
    acid in the kidney was expected since it had also been found to be
    excreted in the urine (Cullen and Mattson, 1968).

    
    TABLE 3. RESIDUES IN MILK OF COWS AND TISSUES OF CALVES PER BROMOPROPYLATE AT VARIOUS RATES
             FOR 30 AND 70 DAYS, RESPECTIVELY

                                                                                              
                                   Duration        Residues in ppm
    Animal        Bromopropylate   of treatment
                  ppma             (days)          Bromopropylate                DBBAb
                                                                                              

    Milk cows     3                30              Milk:       0.06
                  5.3                                          0.10
                  11.7                                         0.18
                  54.8                                         0.84

                                                   After:      28       70       28       70c
                                                   (days)

    Calves        5                70              Fat:        1.5      2.8      n.d.d    n.d.
                                                   Muscle:     <0.04    0.19     n.d.     n.d.
                                                   Liver:      0.16     0.50     0.03     0.14
                                                   Kidney:     0.17     0.07     0.03     0.10

                                                   After:      28       84       28       84c
                                                   (days)

    Calves        50               70              Fat:        7.3      0.3      n.d.     n.d.
                                                   Muscle:     0.42     <0.04    n.d.     n.d.
                                                   Liver:      0.04     <0.04    0.14     n.d.
                                                   Kidney      0.05     <0.04    0.13     n.d.
                                                                                              

    a Concentration in food.

    b DBBA = 4,4'-dibromobenzilic acid.

    c Days after first administration,

    d n.d. = not detectable (<0.02).
    
         In a study with calves which were kept on a diet containing 5 and
    50 ppm bromopropylate for 70 days (Cullen and Mattson, 1968) residues
    were determined in various tissues. Residues in muscle, liver and
    kidney were of the order of 0.5 ppm but decreased to below the limit
    of determination two weeks after the compound was withdrawn from the
    feed. Residues in fat reached 8 ppm but declined to 0.3 ppm in 14 days
    (see Table 4).

    TABLE 4. RESIDUES IN TISSUES OF CALVES FED BROMOPROPYLATE WITH
             THEIR DIET AT TWO RATES FOR 10 WEEKS

                                                                 
                                   Residues found (ppm)
                                                                 

    Tissue       Weeks    Bromopropylate         DBBAa
    analysed
                          5 ppm    50 ppm        5 ppm     50 ppm
                          fed      fed           fed       fed
                                                                 

    Fat          4        1.5      7.3           n.d.b     n.d.
                 6        1.5      8.0           n.d.      n.d.
                 10       2.8      -             n.d.      n.d.

                 12       -c       0.3           n.d.      n.d.

    Muscle       4        <0.04    0.42          n.d       n.d.
                 6        0.22     0.13          n.d.      n.d.
                 10       0.19     -             n.d.      n.d.

                 12       -        <0.04         n.d.      n.d.

    Liver        4        0.16     0.04          0.03      0.14
                 6        0.12     0.11          0.08      0.50
                 10       0.50     -             0.14      -

                 12       -        <0.04         -         <0.02

    Kidney       4        0.17     0.05          0.03      0.13
                 6        0.30     1.04          0.02      0.50
                 10       0.07     -             0.10      -

                 12       -        <0.04         -         <0.02
                                                                 

    a DBBA = 4,4'-dibromobenzilic acid.

    b n.d. = not detectable (<0.02).

    c not analysed.

    TABLE 5. RECOVERY OF RADIO-ACTIVITY AFTER APPLICATION OF
             14C-BROMOPROPYLATE TO SOYBEAN LEAVES

                                                                 

    Days after treatment          0         8         16

    Radio-activity recovered      95.5%     83.9%     62.6%
                                                                 

    In plants

         Only slight translocation of bromopropylate was observed in
    soybeans after topical application of the 14C-labelled compound to
    the leaves (Hassan and Knowles, 1969). In this study an auto-radiogram
    of a leaf prepared 39 days after treatment revealed that the bulk of
    the radio-activity was still confined to this leaf and that only a
    minute translocation took place into the petiole. Table 5 shows that
    95.5, 83.9 and 62.2% of the applied radio-activity was recoverable
    from these leaves, 0, 8 and 16 days after application.

         The behaviour of 14C-bromopropylate was followed on apples,
    apple leaves and in soil after spraying apple trees to run-off with 60
    g active ingredient per 100 l spray mixture (Cassidy, 1968; Cassidy et
    al., 1968),  For residue determination, samples were taken
    periodically until harvest 40 days after treatment. The study showed
    that bromopropylate remains in the surface waxes of the apple peel and
    does not penetrate into the pulp). This is clearly documented by the
    photograph of an apple radio-autogram, (Cassidy, 1968a). Residue
    levels compiled in Table 6 show only an insignificant amount of
    bromopropylate in the pulp.

         These traces of bromopropylate might be due to contamination by
    the paring knife during the peeling procedure rather than to true
    penetration of the compound into the pulp.

         To determine whether any metabolites were present in or on apples
    at harvest time, aliquots of peel and pulp extracts were
    chromotographed on TLC-plates and then autoradiographed. Ninety per
    cent. of the radio-activity was intact bromopropylate, about 2% proved
    to have the Rf-value of 4,4'-dibromobenzilic acid. About 9% of the
    radio-activity was not extractable, corresponding to a residue value
    below 0.1 ppm, expressed as bromopropylate. No bromobenzoic acid,
    4,4'-dibromobenzophenone, or 4,4'-dibromobenzohydrol were detected.

         No significant loss of radio-activity from the apples occurred
    during 40 days. The decrease in residue concentration was mainly due
    to growth dilution; the values were initially 1.0-1.5 ppm and about
    0.5 ppm at harvest. In an experiment (Cassidy, 1967) with a wax
    coated, flask, streaked with a solution of 14C-bromopropylate and
    then placed in a wind chamber (turbulent air flow), it could be shown
    that the loss in bromopropylate by volatilization is practically
    negligible. To determine whether degradation occurred on or in the
    apple leaves, random samples were taken after various intervals (Table
    6) from two sprayed trees. The leaves were extracted with acidified
    acetone and water. The acetone was removed and the extract partitioned
    between chloroform and water. The radio-activity was determined in
    each phase of the stripping solution and in the residue of the
    extraction. To characterize the radio-activity in the chloroform
    fractions, aliquots were chromatographed on TLC. Leaves representing
    each sampling interval were radio-autographed (Cassidy, 1968b).

    TABLE 6. RESIDUES OF 14C-BROMOPROPYLATE IN AND ON APPLE FRUITS
             AND LEAVES AT VARIOUS INTERVALS AFTER TREATMENT
                                                                     
                        ppm values equivalent to 14C-bromopropylate
    Interval (days)     0        1 ´      5        12       19       40
                                                                     
    Whole apple         1.25                                         0.5

    Peel                8.2      2.3               2.1               5.8

    Pulp                0.06     0.03              0.02              0.08

    Leaves of tree I    89.9     47.4     49.5     47.3     25       26.1

    Leaves of tree II   108.6    69.5     69.3     46.4     19.8     15.3
                                                                     

         In these radio-autograms the leaves, especially the veins, were
    well outlined and even 40 days after application the radioactivity was
    mainly confined to individual spots indicating that practically no
    distribution had occurred (Cassidy, 1968b).

         Immediately after spraying, average ppm levels of
    14C-bromopropylate on leaves were about 100, whereas after 40 days
    they were from 15 and 26. The radio-activity on leaves decreased
    considerably. However, rain during the fifteenth and sixteenth day
    after treatment was a main cause of its removal (see Table 6).
    14C-bromopropylate is evidently more tenaciously held by waxes on the
    surface of apple fruits than by waxes on the surface of leaves, as the
    loss from apple fruits is very slow.

         At harvest, 40 days after treatment, 94% of the remaining
    radio-activity on apples was extractable with chloroform. The only
    transformation product identified was 4,4'-dibromobenzilic acid and
    this amounted to approximately 7%.

    In soil

         Residue studies were conducted in various types of soil after
    direct application as well as after spraying fruit trees. Residues
    extracted from soils 40 days after treatment with 14C-bromopropylate
    consisted of up to 95% unchanged bromopropylate. The half life in
    sandy soil was found to be approximately 60 days and in silt loam
    approximately 30 days (Kahrs, 1969e, 1970, 1971).

         In soil samples collected under apple trees treated with
    14C-bromopropylate (Cassidy, 1968b) a large variation in
    radioactivity occurred. The initial level of bromopropylate was about
    0.04 ppm. Following heavy rain 40 days after treatment the average was
    0.6 ppm. About 1-3% of the extractable radioactive residues were
    identified as 4,4'-dibromobenzilic acid; 4,4'-dibromobenzohydrol and

    4,4'-dibromobenaophenone were not detected in soil as was the case in
    plants and animals. The unextractable radio-activity in soil remained
    small, about 6-9% (Cassidy, 1968b, 1969, 1970).

    In storage and processing

    Fruit cooking

         Fortified and field-sprayed apple samples were cooked for 15 and
    30 minutes (Blass, 1973c) to determine the effect of cooking on the
    residues. The untreated samples were fortified with 5 ppm
    bromopropylate. The field treated apples had residues of 0.69 and 0.41
    ppm. As indicated in Table 7, cooking for 15 minutes removed 50% or
    more bromopropylate in both the fortified and the field-sprayed
    samples. After 30 minutes cooking only about 20% of the compound could
    be detected.


    TABLE 7. RESIDUES OF BROMOPROPYLATE IN APPLES AFTER COOKING THE
             FORTIFIED AND TREATED SAMPLES

                                                                    

    Sample         ppm      ppm before   Time of cooking   ppm found
                   added    cooking      (minutes)
                                                                    

                                         15                2.5
    Fortified      5.0      5.0
                                         30                1.3
                                                                    

                                         15                0.27
                            0.67
                                         30                0.10

    Sprayed        -
                                         15                0.20
                            0.41
                                         30                0.07

                                                                    


    Tea - manufacture and brewing

         The tea manufacturing process consisting of withering, rolling,
    fermentation and firing the tea leaves has considerable effect on the
    level of residues of bromopropylate on tea. A series of trials in
    Indonesia showed that the manufacturing process reduced the levels to
    35-40% of the level found after air-drying alone (19.5 ppm declined to
    8.3 ppm).

         Experiments in India showed that little, if any, of the
    bromopropylate in tea leaves was extracted by the hot water in the
    brewing process. The wet leaves after brewing contained almost the
    same amount of residue as the same leaves before brewing.

    Methods of residue analysis

         Residues of bromopropylate can be determined by specific methods
    utilizing gas chromatography and thin-layer chromatography.
    Electron-capture detectors, microconlometric detectors and flame
    ionization detectors have been successfully used (Geigy, 1968, 1968a,
    1969; Cannizzaro et al., 1968).

         For the determination of bromopropylate in hops and beer a more
    rigid clean-up was developed (Geigy, 1968b). Residues of
    bromopropylate in milk and animal tissues were determined by GLC using
    electron capture detector (Geigy, 1968c).

    National tolerances

         Tolerances and waiting periods for bromopropylate in different
    countries are compiled in Table 8. The values for tolerances and
    waiting periods vary considerably from country to country for the same
    crop, as a result of different climatic conditions, and differences in
    agricultural practices - both factors influencing the rate of
    dissipation of the residue.

        TABLE 8. NATIONAL TOLERANCES AND WAITING PERIODS FOR BROMOPROPYLATE
             ON PLANT PRODUCTS
                                                                       
    Countries      Crops                         Tolerance      Waiting
                                                 (ppm)          period
                                                                (days)
                                                                       
    Australia      Pome & stone fruits           5              21

    Austria        Pome & stone fruits           -
                   horticultural crops           -              21

    Bulgaria       General                       -              7

    France         Pome & stone fruits           -              15

                   grapevines

    Israel         Citrus, grapevines,           -              7
                   apples, pears,
                   vegetables

    Japan          Fruits, citrus, hops          -              -

    TABLE 8. (Cont'd.)
                                                                       
    Countries      Crops                         Tolerance      Waiting
                                                 (ppm)          period
                                                                (days)
                                                                       
    Netherlands    Apples & pears                2              21

    South Africa   Bananas,                      5              14
                   citrus, cotton                5              10

    Spain          Fruits                        -              15

    Switzerland    Pome & stone fruits           1.5            21

    USSR           Cotton                        -              20

    Yugoslavia     Field crops, fruits,          -              7
                   vegetables, strawberries      -              10
                                                                       
    
    Appraisal

         Bromopropylate (isopropyl-4-4'-dibromobenzilate) is a contact
    miticide active against all stages of a wide range of mites. The main
    fields of application are in pome and stone fruits, citrus,
    grapevines, hops and cotton where it is applied at the rate of 37.5-50
    g/100 l. It is registered for sale in more than 15 countries. The
    properties and uses are in many ways similar to those of
    chlorobenzilate and chloropropylate (FAO/WHO 1965b, 1969b, 1973b).
    Commercial formulations are only emulsifiable solutions. The technical
    grade contains a minimum of 88% isopropyl-4, 4'-dibromobenzilate. The
    impurities have been identified and quantified.

         Bromopropylate is only recommended for application to growing
    plants. Usually one treatment is sufficient but multiple applications
    are necessary in some instances. No post-harvest treatments are
    approved and to date there are no uses on animals.

         Bromopropylate is non-systemic and non-penetrating. It shows
    remarkable residual effect against mites on leaves. It remains on the
    peel and does not migrate into the pulp of fruits. The concentration
    of residues is proportional to the amount of active ingredient
    applied. Multiple applications have an additive effect and result in
    higher residues. The dissipation of residues is mainly due to
    weathering and growth dilution. The half-life period on most fruits is
    three weeks though on leafy crops such as hops and tea the rate of
    dissipation is much greater.

         Extensive data were available from supervised field trials on
    pome fruits, stone fruits, grapes, citrus, strawberries, bananas,
    vegetables, cotton, hops and tea in 11 countries.


    
    TABLE 9.
                                                                                                                                               
                                             Application                              Interval between last treatment and sampling
                                                                                                          (days)
    Country                                                  Commodity                Residues of bromopropylate in ppm
    (year)                      Number of    Dose g a.i./    analysed                                                                          
                   Formulation  treatment    100 l                          0         7         14        21        28        35        42
                                                                                                                                               

    APPLES

    Switzerland       25E       1            37.5            Whole fruit    2.0       1.1       1.2       0.8       0.9       0.8
    (1966)                                                   Peel                               9.0

    Switzerland       50E       1            25              Whole fruit    2.2       1.4       1.0                 0.5                 0.08
    (1967)            50E       1            37.5            Whole fruit    2.9       0.8       0.7                 0.6                 0.15

    South Africa      25E       1            37.5            Whole fruit    2.0                           1.3       1.5
    (1969)

    USA               25E       1            30              Whole fruit              1.2       0.48      0.73      0.88      0.31      0.36
    (Washington)      25E       1            60              Whole fruit              1.8       1.3       0.94      0.67      0.49      0.67
    (1968)

    Australia         30E       2            37.5            Whole fruit    1.85      1.07      1.15      1.01      0.77      0.77
    (1970)            30E       1            75              Whole fruit    1.76      1.46      1.3       1.21      1.16      1.17
                      30E       2            37.5            Whole fruit    1.59      1.42      1.04      0.8       0.8       0.75
                      30E       2            75              Whole fruit    3.58      2.44      2.45      2.06      1.93      1.87
                      30E       2            50              Whole fruit    2.23      1.81      1.43      1.38      1.37      1.28      1.27
                      30E       2            50              Whole fruit    2.73      2.73      2.27      2.25      2.10      1.9       1.97

    PEARS

    Switzerland       25E       1            25              Whole fruit    0.7       0.5       0.5       0.4                 0.4
    (1967)            25E       1            37.5            Whole fruit    0.85      0.65      0.65      0.5                 0.3
                      50E       1            25              Whole fruit    0.5       0.5       0.35      0.25                0.4
                      50E       1            37.5            Whole fruit    0.85      0.55      0.3       0.3                 0.6

    TABLE 9. (Cont'd.)

                                                                                                                                               
                                             Application                              Interval between last treatment and sampling
                                                                                                          (days)
    Country                                                  Commodity                Residues of bromopropylate in ppm
    (year)                      Number of    Dose g a.i./    analysed                                                                          
                   Formulation  treatment    100 l                          0         7         14        21        28        35        42
                                                                                                                                               

    Switzerland       25E       1            37.5            Whole fruit
    (1971)

    South Africa      50E       1            75              Whole fruit    2.0                                     1.0                 1.0
    (1969)

    BANANAS           50E       1            25              Peel                     5.6
    South Africa                                             Pulp                     0.19
    (1968)

    GRAPES
    Switzerland       50E       1            25              Whole fruit    1.0       0.9       1.1       0.8       0.4       0.2       0.2
    (1967)                                   37.5            Whole fruit    1.2       1.2       1.5       2.1       1.8       0.4       0.4
                      25E       1            25              Whole fruit    0.7       0.8       0.4       0.4       0.15
                      25E       1            37.5            Whole fruit    0.6       1.0       0.5       0.5       0.4
                      50        1            25              Whole fruit    0.7       0.8       0.4       0.3       0.2
                      50        1            37.5            Whole fruit    0.9       0.9       0.7       0.6       0.3
                      25E       1            25              Whole fruit    0.9       1.1       0.9       0.5       0.7       0.4       0.4
                      25E       1            37.5            Whole fruit    1.3       1.0       1.0       0.9       0.7       0.6       0.5

    Israel            50E       1            75                                       3.4       1.5
    (1972)

    GRAPEFRUIT

    USA               25E       1            30              Whole fruit    1.1       1.2       1.3                 1.3
    (California)      25E       1            60              Whole fruit    1.3
    (1968)

    LIMES
    USA               25E       3            30              Whole fruit    0.96      1.5       1.4                 0.96

    TABLE 9. (Cont'd.)

                                                                                                                                               
                                             Application                              Interval between last treatment and sampling
                                                                                                          (days)
    Country                                                  Commodity                Residues of bromopropylate in ppm
    (year)                      Number of    Dose g a.i./    analysed                                                                          
                   Formulation  treatment    100 l                          0         7         14        21        28        35        42
                                                                                                                                               

    (Florida)         25E       3            60              Whole fruit    2.7                 2.5                 2.8
    (1968)            25E       3 + oil      60              Whole fruit    3.0                 3.3                 2.9

    ORANGES

    Israel            50E       1            25              Peel                     1.9       1.4                 1.65                1.65
    (1973)                                                   Pulp                     0.05      0.055               <0.04               0.045

    PEACHES

    Australia         30ES      1 airblast   50              Whole fruit    3.1       2.02      1.36      1.21      1.13      0.5
    (1970)            30ES      1 hand spray 50              Whole fruit    6.9       3.8       2.58      1.61      1.13      0.7
                      30ES      1 airblast   37.5            Whole fruit    2.86      1.35      0.70      0.66      0.79      0.3
                      30ES      1 airblast   37.5            Whole fruit    1.68      1.00      0.92      0.71      0.54      0.51

    PLUMS

    Switzerland       25E       1            25              Whole fruit    2.1       1.1       0.8       0.7       1.2       0.7
    (1967)            25E       1            37.5            Whole fruit    1.9       2.3       1.4       1.0       1.4       0.6
                      50E       1            25              Whole fruit    1.4       0.4       0.8       0.6       0.4       0.3
                      50E       1            37.5            Whole fruit    1.7       1.4       0.8       0.7       0.5       0.3
                      25E       1            37.5            Whole fruit    1.5       1.2       0.7

    STRAWBERRIES

    USA               -         2            60              Fruits         8.3
    (Florida)
    (1969)

    TABLE 9. (Cont'd.)

                                                                                                                                               
                                             Application                              Interval between last treatment and sampling
                                                                                                          (days)
    Country                                                  Commodity                Residues of bromopropylate in ppm
    (year)                      Number of    Dose g a.i./    analysed                                                                          
                   Formulation  treatment    100 l                          0         7         14        21        28        35        42
                                                                                                                                               

    TOMATOES

    Israel            50E       1            1 kg a.i./ha    Whole fruit              <0.10     0.11      <0.10
    (1971)                                                                            0.12      <0.10     0.10

    EGG-PLANTS

    Israel            50E       1            1 kg a.i./ha    Fruits                   <0.1      <0.1      <0.1
    (1971)                                                                            <0.1      <0.1      <0.1

                                                                                                                                               
                                                                            3         9         14        16
                                                                                                                                               

    COTTON

    South Africa      50E       1            50              Seed           <0.02     <0.02               <0.02
    (1968)                                                   Fibres         0.22      0.06                0.11

                                                                                                                                               

                                                                          0      1      4      7      9      14     15     21     26     37
                                                                                                                                               

    TEA

    Indonesia         50E       1           18.75         Dried leaves           22.5   19.5   1.7    0.15
    (1968)                                                Manufactured           30.0   8.3    3.8    2.5
                      50E       1           37.5          Dried leaves           55.0   20.5   19.5   0.5
                                                          Manufactured                  7.8    4.9    0.36

    TABLE 9. (Cont'd.)

                                                                                                                                               
                                             Application                              Interval between last treatment and sampling
                                                                                                          (days)
    Country                                                  Commodity                Residues of bromopropylate in ppm
    (year)                      Number of    Dose g a.i./    analysed                                                                          
                   Formulation  treatment    100 l                          0         1       4      7      9      14    15    21    26     37
                                                                                                                                               

    HOPS

    Germany           25E       1           25            Fresh                       12.8           10.7          6.0         3.9
    (1967)            25E       1           25            Dried             56.5                     38.0          27.0        27.4
                      25E       1           25            Fresh             13.0                     8.6           5.8         4.8
                      25E       1           25            Dried             43.0                     32.0          32.0        27.4
                                                                                                                                               

    
         The rate of dissipation has been measured by chemical analysis as
    well as with radio-labelled compound and it is evident that
    volatilization is not significant. Rain is an important factor in
    reducing residues but this affects leaves more than fruit, no doubt
    due to the protective effect of the heavier wax layers on fruits.

         The residues at harvest are principally the parent compound with
    approximately 7% being 4,4'-dibromobenzilic acid. No bromobenzoic
    acid, 4,4'-dibromobenzophenone or 4,4'-dibromobenzohydrol could be
    detected.

         Studies were available to show the fate of residues in soil,
    animals, and in fruit, vegetables and plant materials subjected to
    processing.

         Following application to soil, bromopropylate is slowly leached
    throughout the top 10 cm. After 40-60 days the residue extracted from
    both sandy soil and loam consists of unchanged bromopropylate. The
    half-life in arable soil is of the order of 60 days.

         When fed to dairy cows at rates corresponding to 5-55 ppm in the
    ration, bromopropylate residues were found in milk though even at the
    highest level the residue did not exceed 1 ppm. Following withdrawal
    of the chemical from the feed residues in milk declined below limit of
    detection in seven days. Calves fed bromopropylate accumulated
    significant amounts in fat but only small quantities in muscle, kidney
    and liver. Accumulated residues disappeared within 14 days of
    withdrawing the chemical from rations.

         Cooking removed 50% of residues on apples in 15 minutes and 80%
    in 30 minutes. No residues could be detected in brewed tea or beer
    made from tea leaves and hops respectively containing residues at the
    highest level likely to be encountered in practice.

         Analytical methods specific to bromopropylate are available.
    These use GLC with either electron capture, microcoulometric or flame
    ionization detectors. In the hands of those who developed the methods,
    the limit of determination was reported to be from 0.01 to 0.05 ppm.

         National tolerances have been established in only three
    countries.

    RECOMMENDATIONS

         Approved uses of bromopropylate will give rise to unavoidable
    residues which will decline slowly between application and harvest.
    However, following good agricultural practice, including waiting
    periods of the following order, the residues at harvest will not
    exceed the following limits which are recommended as maximum residue
    limits for the specified commodities moving in trade. Where single
    treatments are adequate to control mite infestations, residues will be
    considerably less.

         No significant loss of residues is expected during storage or
    shipping. Preparation and processing will reduce residue levels
    considerably so that food as consumed will contain only a fraction of
    the amount of residues indicated.

                                                                          
                                                         Based on interval
                                           Tolerances        (days)
                                            (ppm)        from application
                                                            to harvest
                                                                          
    Apples, bananas (whole),                  5                 21
    cherries, citrus, grapes,
    nectarines, peaches, pears,
    plums, prunes

    Strawberries                              5                 14

    Hops (dried)                              5                 56

    Tea (manufactured)                        5                  8

    Vegetables, cotton seed                   1                 14

    Banana (pulp), citrus pulp                0.2               21
                                                                          

    FURTHER WORK OR INFORMATION

    Desirable

    1.   Studies to elucidate the effects on survival rate of rats
         on long-term feeding.

    2.   Long-term studies in a second species of animal.

    3.   Studies on the effects of bromopropylate on the liver.

    REFERENCES

    Blass, W. Neoron-Cooking experiments with apples. Report SPR 22/73
    1973c

    Cannizzaro, R., Cullen, T., Kahrs, R. A, and Mallsen, A. M.
    1968                Specificity of gas-chromatographic determination
                        of Acarol residues,  Unpublished from Geigy
                        Chemical Corporation, N.Y.

    Cassidy, J.F. Progress report. Fate of 14C GS 19851 on
    1967                apples. Unpublished report from Geigy Chemical
                        Corporation, N.Y.

    Cassidy, J.E. Fate of 14C GS 19851 on apples. A balance
    1968a               study. Unpublished report from Geigy Chemical
                        Corporation, N.Y.

    Cassidy, J.E. Fate of 14C GS 19851 on apples. A balance
    1968                study. Unpublished report from Geigy Chemical
                        Corporation, Ardsley, N.Y.

    Cassidy, J.E. Persistence and stability of 14C GS 19851 in
    1969                soil

    Cassidy, J.E. Further studies on persistence and stability
    1970                of [missing text] in soil.

    Cassidy, J.E. and Min, B. Metabolic fate of 14C GS 19851 in
    1968                white rats. A balance study. Unpublished report
                        from Geigy Chemical Corporation, Ardsley, N.Y.

    Cassidy, J.E., Mattson, A., Cullen, T. and Min, B. The
    1968                metabolic fate of 14C GS 19851 administered to a
                        cow by capsules;  Unpublished report from Geigy
                        Chemical Corporation, Ardsley, N.Y.

    Ciba/Geigy Comprehensive results of supervised trials with
    1969/73             bromopropylate. Unpublished reports filed with
                        FAO, August 1971

    Coulston, F., Fabian, R.J. and Benitz, K.F. Two-year safety
    1970a               evaluation study of isopropyl
                        4,4'-dibromobenzilate in albino rats by dietary
                        feeding. Unpublished report from Institute of
                        Experimental Pathology and Toxicology, Albany
                        Medical College, Albany, N.Y. Submitted by Geigy
                        Chemical Corporation.

    Coulston, F., Fabian, R.J., Abraham, R. and Benitz, K. F.
    1970b               Two-year safety evaluation of isopropyl 4,4'-
                        dibromobenzilate in beagle dogs. Unpublished
                        report from Institute of Experimental Pathology
                        and Toxicology, Albany Medical College, Albany,
                        N.Y. Submitted by Geigy Chemical Corporation

    Coulston, F., Le Fevre, R. and Fabian, R. Three generation
    1971a               study with GS 19 851 in albino rats. Unpublished
                        report from the Institute of Experimental
                        Pathology and Toxicology, Albany Medical College,
                        Albany, N.Y. Submitted by Geigy Chemical
                        Corporation

    Coulston, F., Le Fevre, R. and Fabian, R. Three generation
    1971b               study with GS 19 851 in albino rats. Unpublished
                        report from the Institute of Experimental
                        Pathology and Toxicology, Albany Medical College,
                        Albany, N.Y. Submitted by Geigy Chemical
                        Corporation

    Coulston, F. and Benitz, K.F. Supplemental data on studies
    1972                made with GS 19 851 in beagle dogs. Unpublished
                        report from the Institute of Experimental
                        Pathology and Toxicology,  Albany Medical College,
                        Albany, N.Y. Submitted by Geigy Chemical
                        Corporation.

    Cullen, F. and Mattson, A. Storage of Acarol in tissues of
    1968                calves fed two levels of Acarol for ten weeks.
                        Unpublished report from Geigy Chemical
                        Corporation, Ardsley, N.Y.

    Drake, J.C. A 2443 A - Acute median lethal dose in rats.
    1970                Unpublished report from Geigy (U.K.) Ltd.,
                        Stamford Lodge, Wilmslow, England

    Fancher, O. E., Jackson, G. and Kodras, R. Milk residue study
    1968                with GS 19851 - IBT No. J 6328. Unpublished report
                        of Bio-Test Laboratories Incorporated (USA)

    Fancher, O. E., Schoenig, G. and Keplinger, M. L. Acute
    1968a               toxicity studies on GS 19 851 2 E (GA-494) -  IBT
                        No. A 6194. Unpublished report from the Industrial
                        Bio-Test Laboratories Incorporated, Northbrook,
                        Illinois. Submitted by Geigy Chemical Corporation

    Fancher, O.E., Schoenig, G. and Keplinger, M. L. Acute
    1968b               toxicity studies on GS 19 851 25 W (GA-481) IBT
                        No. A 6196. Unpublished report from the Industrial
                        Bio-Test Laboratories Incorporated, Northbrook,
                        Illinois. Submitted by Geigy Chemical Corporation

    Fancher, O.E., Jackson, G. and Palazzolo, R. Meat residue
    1968C               study - beef calves - GS-19 851 - IBT No. J 6329 
                        - Unpublished report from Industrial Bio-Test
                        Laboratories Incorporated, Northbrook, Illinois.
                        Submitted by Geigy Chemical Corporation.

    FAO/WHO Evaluations of some pesticide residue in food (1965,
    1965b,              1968 and 1972 respectively). Monographs of Joint
    1969b               FAO/WHO meeting of Experts on Pesticide Residues
    1973b

    Geigy Geigy Chemical Corporation, Ardsley, N.Y. Unpublished
    1968-69             Reports filed with FAO (August 1973)

    Geigy Australia Geigy Australia Ltd, Kemps Creek, New South Wales.
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    1967-69             of residue trials. Filed with FAO (August 1973)

    Hassan, T. K. and Knowles, Ch. O. Behaviour of three C14 labelled
    1969                benzilate acaricides when applied topically to
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                        diet for 30 days. Unpublished report from Geigy
                        Chemical Corporation

    Murchison, T. E. Metabolic study of 14C GS 19 851 in a cow.
    1968                Unpublished report from Dawson Research
                        Corporation, Orlando, Florida. Submitted by Geigy
                        Chemical Corporation

    Paterson, R. A. and Drake, J.C. GS 19 851 13-week oral toxicity
    1967                study in rats. Final report - Amendment to the
                        report. Unpublished from Geigy (U.K.) Ltd.,
                        Stamford Lodge, Wilmslow, England

    Paterson, R. A. GS 19 851 28-day oral toxicity study in rats.
    1967a               Final report. Unpublished, from Geigy (U.K.) Ltd.,
                        Stamford Lodge, Wilmslow, England

    Paterson, R. A. GS 19 851 30-day oral toxicity study in dogs.
    1967b               Final Report. Unpublished, from Geigy (U.K.) Ltd.,
                        Stamford Lodge, Wilmslow, England

    Stenger, E. G. Akute Toxizität, Ratte per os, Nr. 295/14217.
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                        Switzerland

    Ueda, K. and Kondo, T. Report on experiment of acute toxicity.
    1968                Unpublished report from Tokyo Dental College,
                        Hygienics Laboratory, Tokyo, Japan. Submitted by
                        Geigy Chemical Corporation

    Vial, J., Ostrovsky, V. and Monterrat, G. Un nouveau
    1971                acaricide: le dibromobenzilate d'isopropyl.
                        Phytiat -  Phytopharm. 20: 31

    Westigard, P. H. and Barry, D. W. Life history and control of
    1970                the yellow spider mite on pear in southern Oregon.
                        J. Econ. Entom., 63: 1433
    


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