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    FAO, PL:CP/15
    WHO/Food Add./67.32

    EVALUATION OF SOME PESTICIDE RESIDUES IN FOOD

    The content of this document is the result of the deliberations of the
    Joint Meeting of the FAO Working Party and the WHO Expert Committee on
    Pesticide Residues, which met in Geneva, 14-21 November 1966.1

             
    1 Report of a Joint Meeting of the FAO Working Party and the WHO
    Expert Committee on Pesticide Residues, FAO Agricultural Studies, in
    press; Wld Hlth Org. techn. Rep. Ser., 1967, in press

    METHYL BROMIDE

    IDENTITY

    Synonym

    Bromomethane

    Formula

    CH3Br

    BIOLOGICAL DATA AND TOXICOLOGICAL EVALUATION

    Biochemical aspects

    After absorption, methyl bromide appears to be broken down by the
    mammalian body, at least in part, for the level of non-volatile
    bromide in the blood and tissues rises significantly. There is also
    some evidence that volatile bromide, presumably unchanged methyl
    bromide, is stored in tissues which are rich in lipoid material. It is
    doubtful, however, whether these findings are relevant to the
    consideration of the residues to be found in foodstuffs fumigated with
    methyl bromide, because in this process as commercially practised no
    unchanged methyl bromide persists (von Oettingen, 1946).

    Acute toxicity

    For rabbits the minimum acute lethal dose of methyl bromide has been
    estimated at 60-65 mg per kg body-weight, when given by stomach-tube
    as a solution in olive oil (Dudley et al, 1940).

    100 mg/kg of methyl bromide given by stomach-tube as a solution in
    olive oil proved to be fatal to rats in five to seven hours (Miller &
    Haggard, 1943).

    Short-term studies with fumigated foodstuff

    Rat. When an unspecified number of rats was fed on a diet fumigated
    with methyl bromide so as to give a residue in the diet equivalent to
    5760 ppm, calculated as bromide, the animals developed diarrhoea after
    three weeks and, over eight weeks in all, their weight gain was
    slight, their general condition was poor and reproduction ceased
    (Dudley et al., 1940).

    In a further experiment extending over 16 weeks in which, again, the
    number of animals was not disclosed, a residue equivalent to 1304 ppm
    bromide in the diet gave rise to increased sleepiness, reduced
    activity. Increased death-rate, decreased weight gain and cessation of
    activity. Return to a normal diet then led to complete restoration to
    health (Dudley et al., 1940).

    A third experiment was carried out with groups each of 36 young white
    rats, fed on a methyl bromide fumigated diet for 20 weeks. In those
    receiving the diet in which the residue was equivalent to 5760 ppm
    bromide adverse effects were observed - partial limb paralysis, scaly
    tails, a form of xerophthalmia, loss of hair, reduced food intake,
    inactivity, impaired reproduction and increased mortality. By
    contrast, those animals on a diet in which the residue was equivalent
    to 206 and 223 ppm bromide remained apparently healthy, although their
    weight gain was slightly reduced. Finally, where the diet was a mixed
    one containing fresh vegetables, cheese, peanuts, and dried fruits, in
    addition to the rat pellets, all fumigated with methyl bromide at a
    concentration of 3 lb per 1000 ft3 (48 g/m3) so that the residue
    was equivalent to a maximum of 240 ppm calculated as bromide, no
    deleterious effects were seen. In all the experiments there was no
    significant histopathology (Dudley et al., 1940).

    Two groups, each of 25 males and 32 females, were fed for one year on
    a modified Sherman diet, previously fumigated with methyl bromide at
    the rate of 2 lb and 6 lb respectively per 1000 ft3 (16 g to 48
    g/m3) and having an average bromide content of 262 ppm and 637 ppm. A
    group of 10 male and 15 female rats was fed the same basic diet
    unfumigated but with the addition of 0.1 per cent (i.e., 1000 ppm)
    sodium bromide. The control group received the unmodified diet. At the
    end of 12 months none of the animals showed any evidence of adverse
    effect in growth rate, organ weights and results of haematological and
    histological examination (Spencer et al., 1944).

    Rabbit. Groups, each of 12 rabbits, were fed for one year on diets
    which had been fumigated with methyl bromide for 24 hours. When the
    residue was equivalent to 3254 ppm bromide the animals developed a
    progressive paralysis and urinary retention and all died within two
    weeks. In the others, for which the residue was equivalent to 67 and
    75 pm bromide, there were no abnormalities, apart from a slight
    reduction in weight gain and some polydypsia and polyuria. Post
    mortem, bronchopneumonia was common in the high dose group and changes
    were found in the brain (Dudley et al., 1940).

    Dog. Twenty-two beagles of both sexes, in groups of four to six
    animals, were fed for one year on methyl bromide fumigated diets. The
    residues of 1389, 2975 and 6097 ppm led to a bromide intake of
    approximately 35, 75 and 150 mg per kg body-weight daily. Another
    group of dogs was given sodium bromide in the diet at the rate of 100
    mg per kg body-weight daily of bromide. Lethargy was seen only in
    those animals on the high residue intake and there was occasional
    salivation and diarrhoea both in this group and that on sodium
    bromide. Otherwise the animals remained substantially healthy and, on
    post mortem, no significant changes were found (Rosenblum et al.,
    1960).

    Long-term studies

    No long-term studies are available.

    Comments

    No work has been done on the long-term oral toxicity of methyl bromide
    as such. However, it is probable that by far the major part, if not
    all, of the residue which persists in foodstuffs fumigated with methyl
    bromide in accordance with ordinary commercial practice is in the form
    of inorganic bromide. If this is so, the safety of treated products
    could be assessed simply on the basis of their bromide content.

    The question still remains whether the small interaction that takes
    place between the fumigant and the food constituents could lead to a
    significant decrease of nutritional value or to the formation of toxic
    compounds. The answer to this should be provided by the feeding
    studies with animals given a diet which had previously been fumigated.
    These experiments have been short term and covered three species of
    animals. From these it is clear that diets fumigated with methyl
    bromide at the usual rates adopted commercially had no deleterious
    effects on any of the animals.

    TOXICOLOGICAL EVALUATION

    Since nothing is known about the long-term oral toxicity of unchanged
    methyl bromide no acceptable daily intake can be assigned to it as a
    residue.

    To judge by the work on cereal products the interaction of the
    compound with the food is unlikely to have hazardous consequences.

    The minimum pharmacologically effective dosage in the human adult has
    been generally stated to be about 900 mg of KBr, equivalent to 600 mg
    of bromide ion, daily. Assuming an adult weight of 60 kg this dosage
    in man is about 10 mg/kg body-weight/day. In the light of available
    toxicological information obtained from the extensive therapeutic use
    in man, an acceptable daily intake for man of inorganic bromide from
    all food sources can be estimated.

    Estimate of acceptable daily intake for man of inorganic bromide

    0-1.0 mg/kg body weight.

    Further work required for unchanged methyl bromide

    Chemical nature and amount of the residue in foods other than cereals.

    Biochemical studies on the changes produced by methyl bromide in food.

    Results of the above work should be made available not later than
    three years after the publication of this report, when a re-evaluation
    of this compound will be made.

    Depending on the results of the above two studies, additional work
    such as biochemical studies in animals, reproduction studies and
    long-term toxicity studies may be required.

    RESIDUES IN FOOD AND THEIR EVALUATION

    Use pattern

    (a) Pre-harvest treatments

    Methyl bromide is very phytotoxic to growing plants, thus limiting its
    pre-harvest uses. Such uses were reviewed by Page & Lubatti (1963). It
    is applied to soils before planting, at low doses, to some seeds and
    plants for quarantine purposes. These uses do not give rise to
    significant bromide residues in foods.

    (b) Post-harvest treatments

    Methyl bromide is used against storage pests on cereals in many
    countries. Treatment is carried out in various kinds of enclosures,
    including chambers at atmospheric or reduced pressures, in warehouses,
    in box cars and in barges. These are sometimes temporarily adapted for
    the purpose. A few elevators are equipped for forced circulation of
    the fumigant. For economic reasons, treatments are normally reserved
    for specific shipments requiring remedial measures and are not carried
    out as a matter of routine. Much of the methyl bromide used in
    commerce contains an indicator substance (e.g. chloropicrin at two per
    cent) which gives a readily perceptible warning of leakage from
    fumigant containers or from stores being treated.

    It is also occasionally used in admixture with "liquid fumigants". For
    example, a mixture mainly containing carbon tetrachloride has high
    powers of penetration down into standing grain and is sometimes
    applied at the top of deep bins of standing grain. Mixtures with
    ethylene dibromide are also used in a few countries, (Majumder, Muthu
    & Narasinham, 1963) for the fumigation of stocks of grain in bags.
    Some proprietary preparations contain three or more other components
    (e.g. ethylene dichloride, ethylene dibromide, carbon tetrachloride,
    carbon disulfide). Methyl bromide is also used occasionally on
    processed cereals such as flour and milling by-products. It is used on
    a wide range of stored products including dried fruits, pulses, nuts,
    oilseeds, animal feed and other dry foodstuffs; also against insects
    in clothing, furniture and timber.

    Tolerances

    There are no tolerances for unchanged methyl bromide. For inorganic
    bromide derived from fumigation the figures in Brazil, Germany, India,
    the Netherlands, Canada and USA for various cereal are 50 ppm and in
    Czechoslovakia 20 ppm; in New Zealand there is a tolerance of 20 ppm
    in any food.

    Gibich & Petersen (1963) have determined inorganic bromide residues in
    various mill fractions of fumigated and unfumigated wheat. Even with 
    unfumigated wheat great differences were observed in the amounts
    of bromide located in different parts of the grain. The rejected
    fractions (screenings and scourers) ran at 50-100 ppm approximately
    whether fumigated or not, whereas flour and feed fractions gave Br
    residues up to four times higher in treated, compared with untreated
    samples. The type of wheat itself to some extent determines the amount
    of Br found in certain fractions and there is some correlation between
    bromide level and fat and protein contents. Some results obtained are
    summarized in Table II.

        TABLE II. TOTAL BROMIDE RESIDUE IN MILL FRACTIONS FROM TREATED WHEAT (PPM)

                                                                               
    Mill fraction       Hard red winter wheat          Hard red spring wheat
                                                                               

    Clean wheat        11.7     29.7       38.6            18.2       39.1

    A grade flour      11.0     18.6       22.9            19.1       21.3

    X grade flour      24.3     28.0       30.9            35.8       31.8

    Y grade flour      21.0     39.5       36.6            38.3       36.9

    Head shorts        10.3     60.8       79.8            22.9       96.0

    Tall shorts        17.6     60.1       75.2            31.5      101.2

    Bran               10.0     42.6       57.1            19.1       56.1

    Germ               16.4    109.4      113.2            18.0      212.8

    Dirty wheat         8.9     25.3       35.1            17.8       43.1

    Screenings         51.9     55.1       60.8            17.8       71.5

    Scourers           72.8     82.6      115.8            62.6      119.9
                                                                               
    
    An examination of 227 grain shipments to the Netherlands from all
    parts of the world in the period May 1964 to September 1965, showed
    inorganic bromide residues to be present in only 14 of these. The
    measurement of residues of unchanged fumigants are still being
    developed but preliminary observations on the 227 shipments above
    showed that residues of unchanged methyl bromide, if any, did not
    exceed 0.1 ppm.

    Residues resulting from supervised trials

    During the exposure period some of the fumigant is sorbed1 by the
    cereals or cereal products. The amount increases with the dosage used
    under given circumstances and a higher moisture content usually
    results in a higher residue. For example, some wheat of nine per cent
    moisture content exposed at 32 g/m3 for 24 hours, gave an immediate
    total bromide figure of 30 ppm whereas one at 15 per cent moisture
    under the same experimental conditions gave 99 ppm (Lindgren, Gunther
    & Vincent, 1962).

    As shown by Lubatti & Harrison (1944), Shrader, Beshgetoor & Stenger
    (1942) and Winteringham (1955) immediately after the termination of
    the exposure period the residue consists partly of unchanged methyl
    bromide and partly of a fixed residue resulting from some kind of
    reaction with constituents of the food. The unchanged methyl bromide
    disappears quite rapidly leaving a fixed residue which does not
    decrease on further airing. This fixed residue behaves as inorganic
    bromide. As examples of the rate of disappearance of unchanged methyl
    bromide, the above-mentioned wheat, which had contained a total of 30
    ppm immediately after treatment contained 19 ppm six hours later and
    17 ppm after eight days and that which had contained 99 ppm
    immediately gave 78 ppm and 77 ppm after these same intervals of time.
    These losses are due to disappearance of unchanged methyl bromide.
    Flour has been found to take up rather more than wheat when they are
    exposed under identical conditions.

    Winteringham (1955) showed that the fixation of the methyl bromide is
    due mainly to reaction with the protein fraction mainly by methylation
    of nitrogen and sulfur-containing groups with the formation of
    methylated histidines, dimethyl sulfonium derivatives and lesser
    amounts of methoxy and thiomethoxy derivatives. These reactions have
    not been considered to be sufficient to reduce the nutritive value of
    the products.

    Figures for residues after commercial, or simulated commercial
    treatments of wheat and flour vary widely. In one test with cornflour,
    Wagner (personal communication) gives 75 ppm. In another case a figure
    as high as 150 ppm for total bromides was reported in flour
    immediately after fumigation and before airing had taken place. For
    whole wheat, residues are rather lower than when the processed grain
    such as flour is exposed. Wheat of 12 per cent moisture content
    exposed under commercial conditions gave an initial total bromide
    residue of 35.5 ppm which fell to 14 ppm in 24 hours (Pest Infestation
    Laboratory, 1947). Wheat of 15 per cent moisture content however had a
    residue of 78 ppm after 24 hours, following a fumigation under
    identical conditions. These variations are probably due to the wide

                  
    1 This term is used so as to include all the gas taken up by the
    exposed solid irrespective of the particular mechanism or mechanisms,
    such as solution, surface retention or chemical combination, which may
    be involved in any given case.

    range of conditions of exposure which occur in practice, including
    dosages, period of exposure, tightness of the enclosure, moisture
    content of the cereals and cereal products treated and whether or not
    they are turned or aired before sampling. Burns-Brown et al. (1955)
    reported residues of about 50 ppm, inorganic bromide in flour after
    treatments corresponding to normal commercial practice. The bromide
    content of commercial flour which has not been treated with a fumigant
    of any kind has been reported to fall between 2.4 and 7.7 ppm
    (FAO/WHO, 1964)

    Getzendaner (1966a) measured bromide residues in cocoa beans and
    processing fractions resulting from the experimental fumigation of
    beans with methyl bromide. Under the conditions used (five fumigations
    with 1-1/2 lb methyl bromide per 100 cu. ft for 24 hours; 7-1/2 lb in
    one fumigation, or 4-1/2 lb for 24 hours followed by 4-1/2 lb for 12
    hours), residues of less than 50 ppm bromide were found after 24 hours
    aeration. The shells of fumigated beans contained between four and six
    times the amount found in a whole bean. Cocoa residues were about the
    same as those found in the whole beans, but lower residues were found
    in corresponding butter and nib fractions. Getzandaner & Richardson
    (1966) have measured bromide residues in fruit and vegetables
    experimentally fumigated with methyl bromide. Treatment at atmospheric
    pressure in general gave residues of less than 25 ppm of bromide.
    Yams, however, approached 30 ppm and sweet corn and peas up to 40 ppm
    bromide. Typical results for other produce were: cherries 8 ppm;
    peaches 3 ppm; carrots 20 ppm; oranges, grapefruit 12 ppm; cucumber 15
    ppm; apples 3 ppm; cabbage 20 ppm bromide. Garlic subject to vacuum
    fumigation in commercial chambers had residues of 2 to 11 ppm and
    cipollini bulbs up to 48 ppm bromide. Getzandaner (1965) has also
    shown that poultry meat and eggs from hens fed diets containing up to
    400 ppm bromide residues contain at equilibrium no more bromide
    residue than the diet.

    Bär (1964) found that whilst cereals, fruit and vegetables retained
    only small residues after treatment, flour and oily goods retained
    much higher levels even after 48 hours aeration. Maximum levels (for
    inorganic bromide) cited by the German Federal Office of Health from
    rat feeding studies reported by Bär are: cereals and citrus fruit skin
    50 ppm; almonds and other nuts (kernels) 40 ppm; citrus pulp 25 ppm;
    cocoa beans, dried fruit 10 ppm.

    The feeding of fumigated cereals to cattle may result in bromide
    residues in milk. Lynn (1963) found 10-20 ppm in milk from cows fed a
    diet containing 43 ppm bromide.

    Residues in food moving in commerce

    Duggan, Barry & Johnson (1966) reported total bromide levels of up to
    200 ppm in various defined food groups in total diet studies; results
    are summarized in Table I. Heywood (1966) pointed out that not all of
    this bromide could be attributed to fumigants since part, at least,
    occurred naturally in food.

        TABLE I. BROMIDE RESIDUES IN TOTAL DIET STUDIES

                                                                       
    Foods                  Bromide range ppm          No. of samples
                                                      (out of 18)
                                                                       

    Dairy produce          1.1 to 31.7                17

    Meat, fish             2.3 to 35.5                16

    Grain                  4.4 to 111.0               17

    Potatoes               1.5 to 38.0                15

    Leafy vegetables       1.1 to 16.3                16

    Legumes                0.9 to 17.9                14

    Root vegetables        2.6 to 22.1                14

    Salad fruit            1.7 to 18.9                15

    Fruit                  0.7 to 31.4                12

    Oils, fats             1.1 to 261.0               16

    Sugar, etc.            0.7 to 55.1                18

    Beverages              0.9 to 17.0                10
                                                                       
    
    Fate of residues

    (a) In plants and animals

    There is a fairly extensive literature on the activity and excretion
    of inorganic bromides in animals and man. As indicated by Heywood
    (1966), furthermore, small amounts of bromide occur naturally on a
    fairly wide range of plant products. Residues of "apparent
    organobromine compounds" reported by Gunther & Spenger (1966) were
    said to be due to the extraction of inorganic bromide by organic
    solvents in the presence of lecithin-type complexing agents present in
    vegetable tissues. The results obtained, indicated in Table II,
    probably reflect naturally occurring bromide in the various plants.

    TABLE II. APPARENT ORGANOBROMINE RESIDUES IN PLANT PARTS

                                                             
    Plant                    Plant part             Bromine
                                                    ppm
                                                             

    Atriplex lentiformis     Leaves and stems       4.4
                                                    4.9

    Schinus Molla            Tops                   1.1

    Suaeda sp.               Whole plants           0.3

    Beets                    Tops                   0.15

    Broccoli                 Heads                  0.13

    Chard                    Foliage                0.2

    Corn, sweet              Leaves                 0.15

    Cucumber                 Seeds                  9.9

    Barley                   Whole plants           0.34
                                                    0.26

    Lima beans               Whole plants           0.2

    Onions                   Whole plants           0.18
                                                    0.27

    Peppers                  Whole plants           0.18

    Radishes                 Whole plants           0.1

    Zucchini                 Fruits                 0.13
                                                             


    (b) In storage and processing

    Methyl bromide disappears rapidly from whole wheat and cannot be
    detected after three or four days of airing. The combined bromide does
    not disappear to a significant extent during airing. When fumigated
    wheat has been milled the residues found in the various milling
    fractions, present at the stage as inorganic bromide, have been found
    to vary: the residues in flour and other fractions for human
    consumption, however, have always been appreciably lower than those in
    the original wheat. For example, on one occasion wheat with 14 ppm
    bromide gave flour of 5 ppm but the bran contained 13 ppm (Pest

    Infestation Laboratory, 1947). Wagner (personal communication) quotes
    a wheat of 26.8 ppm which yielded a flour of 12.2 ppm but the bromide
    residues in the animal feed fractions had slightly increased.

    Methods of residue analysis

    Berck (1965) has published details of a gas chromatographic method for
    the detection and measurement of some 34 fumigant vapours, including
    methyl bromide. The application of this technique to the determination
    of residues of unchanged methyl bromide in fumigated foods is most
    desirable. The method of Napes & Shrader (1957), based on the
    measurement of inorganic bromide, is in the meantime suggested as
    suitable for measuring residues of total bromide in cereals after
    fumigation. Working details are set out in Appendix A(4) of the
    (Extract) Report of the Second Session of the FAO Working Party on
    Pesticide Residues (PL/1965/12). The limit of detection is about 1
    ppm.

    The Joint FAO/WHO Expert Committee on Food Additives, when considering
    the presence of bromide in bread due to the addition of bromate
    conditioner to flour (FAO/WHO, 1964) gave estimates of acceptable
    levels of treatment for flour to be consumed by man as:

         Unconditional                            0-20 ppm
         Conditional (for special purposes)      20-75 ppm

    The recommendation of 50 ppm in cereals and flour resulting from
    fumigation, is in accordance with this estimate because cereals and
    cereal products are treated with the fumigant to deal with specific
    outbreaks and not as a routine, during milling or other manufacture,
    as are flour conditioners.

    RECOMMENDATION FOR TOLERANCES

    On the basis of an acceptable dally intake of 1 mg/kg of inorganic
    bromide, a tolerance of 50 ppm for inorganic bromide residues in
    cereals and flour resulting from the use of methyl bromide and other
    fumigants can be recommended. This recommendation is also consistent
    with tolerances for dried eggs, processed herbs and spices at 400 ppm;
    various fresh fruits at 200 ppm; citrus at 230 ppm; raisins, dates at
    100 ppm and various other fruits including certain dried fruits, at
    from 50 ppm to 20 ppm, which are residues which have been found after
    responsible usage of the fumigant and which are as follows:

         Dried eggs, spices, herbs     400
         Cereals                        50
         Dried figs                    250
         Avocados                       75
         Dried raisins, dates          100
         Dried peaches                  50
         Dried prunes                   20

         Other dried fruits             30
         Citrus, strawberries           30
         Other fresh fruit              20

    Since no acceptable daily intake has been established for the
    unchanged compound and since there appears to be no requirement for
    such a tolerance in commercial practice, no tolerance is recommended
    for residues of unchanged methyl bromide.

    Further work or information

    The measurement of residues of bromide, and of unchanged methyl
    bromide (if any) resulting from the use of methyl bromide on raw
    wheat, flour and other food items in commercial practice is desirable.
    There would be particular interest in information on the retention of
    unchanged methyl bromide in foods with a relatively high oil or fat
    content. Further information on residues resulting from the use of
    mixed fumigants is also desirable.

    The Working Party considers that a sensitive multidetection method for
    residues of unchanged fumigants (including methyl bromide) in treated
    foods is now possible and the development of such a method would be a
    valuable advance.

    REFERENCES PERTINENT TO BIOLOGICAL DATA

    Dudley, H. C., Miller, J. W., Neal, P. A. & Sayer, R. R. (1940)
    Publ. Hlth Rep., 55, 2251

    Miller, D. P. & Haggard, H. W. (1943) J. industr. Hyg. Toxicol.,
    25, 423

    von Oettingen, W. F. (1946) Nat. Inst. Hlth Bull., 185

    Rosenblum, I., Stein, A. A. & Eisinger, G. (1960) Arch. environ.
    Hlth, 1, 316

    Spencer, H. C., Rowe, V. K., Adamo, C. M. & Irish, D. D. (1944) Food
    Res., 9, 11

    REFERENCES PERTINENT TO AGRICULTURAL DATA

    Bär, F., (1964) Methylbromide zur Schädlingsbekämpfung
    Bundesgesundheitsblatt, 7: 113

    Berck, B., (1965) Determination of fumigant gases by gas
    chromatography J. Agric. Food Chem. 13 (4): 373-377

    Burns-Brown, W., Coppock, J. B. M., Edwards, G. H., Greer, E. K., Hay,
    J. G. & Heseltine, H. K. (1955) The fumigation of flour with methyl
    bromide. Chem. Ind., March 19, 1955: 324-5

    Duggan, R. E., Barry, H. C. & Johnson, L. Y. (1966) Pesticide residues
    in total-diet samples Science, 151 (3706): 101-104

    FAO/WHO (1964) Specifications for the identity and purity of food
    additives and their toxicological evaluation: emulsifiers,
    stabilizers, bleaching and maturing agents. FAO Nutr. Meetings Rep.
    Ser. 35: 167

    FAO/WHO (1965) Evaluation of the toxicity of pesticide residues in
    food. Rome FAO Meeting Report No. PL/1965/10/2, 71 p.

    Getzendaner, M. E. (1965) Residues in milled wheat products resulting
    from spot fumigation of milk machinery with halogenated liquid
    fumigants. J. Agric. Food Chem., 13: 455-458

    Getzendaner, M. E. (1966a) Bromide residues from methyl bromide
    fumigation of cocoa beans and processed fractions from fumigated
    beans. J. Agric. Food Chem., 14: 56-58

    Getzendaner, M. E. & Richardson, H. H. (1966b) Bromide residues from
    methyl-bromide fumigation of fruits and vegetables subjected to
    quarantine schedules J. Agric. Food Chem., 14: 59-62

    Gibich, J. & Pederson, J. R. (1963) Bromide levels in mill fractions
    of unfumigated and fumigated wheat. Cereal Science Today, 8: 345-354

    Gunther, F. S. & Spenger, R. E. (1966) Apparent organobromide
    compounds in higher plants by neutron activation analysis. Bull.
    Environ. Contam. Toxicol., 1: 121

    Heywood, B. J. (1966) Pesticide residues in total diet samples:
    bromine content. Science, 152 (5727): 1406

    Lindgren, D. L., Gunther, F. A. & Vincent, L. E. (1962) Bromine
    residues in wheat and milled wheat fractions fumigated with methyl
    bromide. J. Econ. Ent., 55: 773-6

    Lubatti, O. F. & Harrison, A. (1944) Determination of fumigants. XVII.
    Comparison of the sorption of hydrogen cyanide, ethylene oxide,
    trichloro-acetonitrile and methyl bromide by wheat. J. Soc. Chem. Ind,
    63: 353-9

    Lynn, G. E., Shrader, S. A., Hammer, O. H. & Lassiter, C. A. (1963)
    Occurrence of bromide in the milk of cows fed sodium bromide and grain
    fumigated with methyl bromide. J. Agric. Food Chem., 11: 87-91

    Majumder, S. K., Muthu, M. & Narasinham, K. S. (1963) Behaviour of
    ethylene dibromide methyl bromide and their mixtures. I: in columns of
    grains and milled materials. Food Technol., 17; 106-111

    Mapes, D. A. & Shrader, S. A. (1957) Determination of total and
    inorganic bromide residues in fumigated products. J. Ass. Offic. Agr.
    Chem., 40: 189-96

    Page, A. B. P. & Lubatti, O. F. (1963) Fumigation of insects. Annu.
    Rev. Ent., 8: 239-64

    Pest Infestation Laboratory. (1947) The effect on the milling and
    baking quality of wheat after fumigation with methyl bromide. Slough,
    Bucks. Pest Infestation Res. Rep. 11 (unpublished document)

    Shrader, S. A., Beshgetoor, A. W. & Stenger, V. A. (1942)
    Determination of total inorganic bromide on food fumigated with methyl
    bromide. Ind. Eng. Chem. Anal. Ed. 14: 1-4

    Winteringham, F. P. W. (1955) The fate of labelled insecticide
    residues in food products. IV. The possible toxicological and
    nutritional significance of fumigating wheat with methyl bromide. J.
    Sci. Food Agr., 6: 269-74
    


    See Also:
       Toxicological Abbreviations
       Methyl Bromide (EHC 166, 1995)
       Methyl bromide (ICSC)
       Methyl bromide (PIM 340)
       Methyl bromide (FAO Meeting Report PL/1965/10/2)
       Methyl bromide (FAO/PL:1967/M/11/1)
       Methyl bromide (FAO/PL:1968/M/9/1)
       Methyl bromide (WHO Pesticide Residues Series 1)
       Methyl bromide (SIDS)
       Methyl Bromide (IARC Summary & Evaluation, Volume 71, 1999)