In 1972 the Joint Meeting (FAO/WHO, 1973) evaluated bromophos-
    ethyl in the light of the information then available. A temporary ADI
    and some temporary tolerances were recommended.

         The Meeting required residue data from supervised trials in
    maize, rice and other cereals, cotton, domestic animals other than
    cattle, and milk products. The Codex Committee on Pesticide Residues
    at its 8th Session requested that a maximum residue limit for milk
    products should be established (Alinorm 76/24, para. 46).

         New information has been received on residues in maize, rape seed
    and green rape resulting from supervised trials, on residues in the
    tissues of dosed and dipped sheep and on residues in butter made from
    the milk of dipped cows. This information is summarized in the
    following monograph addendum.

    Other information on identity and properties

         Solubility: 2 mg/kg water (Eichler, 1972)



    Short-term studies


         Groups of young rats (10 male and 10 female per group) were fed
    bromophos-ethyl in the diet for four weeks at dose levels of 0 and 100
    ppm. Behaviour and mortality were unaffected over this time interval.
    Growth, evidenced by body weight changes, and food and water
    consumption were normal. RBC cholinesterase activity was inhibited
    (50%) within one week after treatment began. Normal activity was
    almost reached one week after treatment ended. At the four week post
    treatment interval, RBC activity was normal. Plasma cholinesterase
    activity was inhibited similarly at one week after feeding began (app.
    60%) and activity again recovered within one week after feeding
    ceased. Cholinesterase depression was rapid but was not progressive.
    The lowest levels of both plasma and RBC cholinesterase activity were
    achieved in one week. Serum ascorbic acid levels, and urine ascorbic
    acid and dehydroascorbic acids levels measured at 0, 1, 2, 4, 5 and 9
    weeks after initiation of the study were normal at all time intervals.
    There were no changes noted in ascorbic or dehydroascorbic acid levels
    in serum or urine (Leuschner, 1975).


         Groups of guinea-pigs (10 males and 10 females/group) were fed
    bromophos-ethyl in the diet for four weeks at dose levels of 0 and 100
    ppm. The animals were maintained on control diets for a further four
    week period to measure recovery from any effects noted. As in the
    previous study, no adverse effects were noted on behaviour, food or
    water consumption, growth or on mortality over the entire test period.
    As noted with rats, plasma cholinesterase activity was depressed
    within one week and maintained at a constant low (40% of normal) level
    until the fourth week. After bromophos-ethyl was removed from the
    diet, the plasma enzyme activity rapidly recovered within one week and
    was normal after four weeks. In contrast to rats, the RBC
    cholinesterase activity of guinea-pigs was not affected by
    bromophos-ethyl at any time interval. Serum ascorbic acid levels and
    urine ascorbic acid and dehydroascorbic acid levels, measured at 0, 1,
    2, 4, 5 and 9 weeks after initiation of the study were normal. There
    were no changes noted in ascorbic or dehydroascorbic acid levels in
    serum or urine (Leuschner, 1975).


         Bromophos-ethyl was evaluated by a previous Meeting and a
    temporary ADI was allocated.

         Studies in rats and dogs showed an increase in urinary excretion
    of ascorbic acid and dehydroascorbic acid in two year rat and dog
    studies as well as shorter-term studies in both species. In an effort
    to further define these effects and to evaluate its relevance to man,
    short-term feeding studies in rats and guinea-pigs were repeated. The
    previously noted increased ascorbic acid and dehydroascorbic acid
    levels in urine were not seen in this study. In addition, blood levels
    of these materials were not altered by bromophos-ethyl in the diet.
    Cholinesterase depression was noted in both species attesting to the
    presence of bromophos-ethyl in the diet.

         The Meeting now considered the rat study to be complete and a
    dietary no-effect level based on cholinesterase depression was
    observed to be 0.78 mg/kg/day. A no-effect level in the dog was 0.26
    mg/kg/day and was utilized as the basis for estimating the ADI.


    Level causing no toxicological effects

         Rat: 0.78 mg/kg body weight/day

         Dog: 10 ppm in the diet equivalent to 0.26 mg/kg body weight


         0-0.003 mg/kg body weight




         In four supervised trials in Germany and in the Netherlands,
    maize was treated against the frit fly (Oscinella frit L.). In
    May/June plants were sprayed with an EC at a rate of 0.54-0.57 kg
    a.i./ha (normal application rate). Residues were determined by GLC
    after pre-harvest intervals between 28 and 154 days. Maximum residues
    of 0.05 mg/kg were found in the kernels 28 days after a single
    application. In all other studies residues in maize plants or kernels
    were at or below 0.02 mg/kg (limit of determination; Celamerck,

         Since two applications may be necessary to control strong
    infestations of insect pests, corresponding residue data should be


         For the 1972 Joint Meeting Report only limited residue data for
    rape seed after a single application of bromophos-ethyl (EC) were
    available. Since rape is treated one to three times, additional data
    have been supplied (Celamerck, 1975b), and are listed in Table 1.


         Additional data on residues on carrots and Brussels sprouts have
    been supplied (Table 1). The data on Brussels sprouts include residues
    found at various stages of household preparation.


         A single dose of 25 mg bromophos-ethyl/kg body weight was
    administered orally to a sheep weighing 33.6 kg (TVL, 1975). The
    levels (mg/kg) in blood were 0.06 (one hour after dosing), 0.32 (three
    hours) and 0.20 (five to seven hours).

         After 72 hours the same sheep was again dosed with 25 mg/kg and
    slaughtered 48 hours later. Maximum residues in organs and fat (two
    samples each) were: muscle 1.0, liver 0.1, kidney 0.28, spleen <0.01,
    brain 0.025, renal and omental fat 13, and back fat 5 mg/kg.

         In another experiment (TVL, 1975) sheep (Romney Cheviot Crossbred
    Hoggets) were dipped in washes containing 0.05% (normal strength) and
    0.1% bromophos-ethyl. The amounts of bromophos-ethyl in the fat of
    these sheep are listed in Table 2.

    TABLE 1.  Bromophos-ethyl residues in crops


                                                        Residue (mg/kg) at interval (days) after application
    Crop                  No.   a.i./ha   0       3-4     7        14      21        24-28       42          60          90

    Brussels sprouts1,2   3     0.6       0.32-   0.26-   0.06-    0.07-   0.03-     0.16-
                                          0.50    0.32    0.46     0.55    0.12      0.35

    "2                    4     0.6       0.05-   0.36-   0.26-    0.15-
                                          0.52    0.63    0.46     0.25

    "3                    1     0.8                       0.11-    0.11-
                                                          0.22     0.19

    "4                    1     0.8                       0.03-    0.03-
                                                          0.10     0.05

    "5                    1     0.8                       <0.04    <0.03

    Carrots6              1     6                                                                            0.49-1.6    0.22-
    Rape seed7            1     0.54                                                                         <0.02

    "                     2     0.43                                                             <0.02       <0.02

    "                     4     0.36                                                 0.35-

    "                     1     0.43                                                             <0.02       0.03
                                                                                                 (50 days)   (56 days)

    TABLE 1. (continued)


                                                        Residue (mg/kg) at interval (days) after application
    Crop                  No.   a.i./ha   0       3-4     7        14      21        24-28       42          60          90

    Rape plants7          3     0.728     19.1    8.6     6.4      3.1     1.9

    "                     3     0.36      9.9     3.9     2.6      1.3     0.8

    1 RIV, 1970
    2 RIV, 1971b
    3 Trimmed (other small leaves removed) RIV, 1974 
    4 After cleaning and washing, RIV, 1974
    5 After cleaning, washing and cooking, RIV, 1974
    6 RIV, 1971a
    7 Celamerck, 1975b
    8 Twice the normal dosage.

    TABLE 2.  Bromophos-ethyl residues in the fat of sheep after dipping


                                  Bromophos-ethyl residues (mg/kg) in
    Period between                                                      
    dipping and        % a.i.
    sampling (days)    in dip     Back fat    Renal fat    Omental fat

    2                  0.05       0.6-1.1

                       0.1        0.7-3.1

    7                  0.05       1.0-3.4

                       0.1        1.5-2.9

    14                 0.05       0.9-1.9     1.5          1.2

                       0.1        0.6-2.5     1.9          2.8

    28                 0.05       0.3-0.4

                       0.1        0.4-1.0

    42                 0.05       0.03-0.14

                       0.1        0.03-0.3

    56                 0.05

                       0.1        0.02        0.10         0.04


         After dipping four lactating dairy cows (Jersey) in a
    concentration of 0.049% (w/v) bromophos-ethyl, milk samples were taken
    from each of the cows, and the butter prepared from these samples was
    analysed for residues (Wollongbar Agric. Res. Stat., 1969). Amounts of
    bromophos-ethyl after various intervals following dipping were as
    follows: 0.49-0.87 (mg/kg butter) at 0 days (after dipping), 0.87-1.13
    at 1 day, 0.35-1.02 at 2 days, 0.24-0.47 at 3 days, 0.08-0.12 at 4
    days, 0.06-0.08 at 5 days, 0.02-0.04 at 6-7 days and 0.01 or below at
    8-17 days.


         The 1972 Joint Meeting, after reviewing the information on
    bromophos-ethyl, required residue data from supervised trials in
    maize, rice and other cereals, cotton, domestic animals other than 
    cattle, and milk products before tolerances could be recommended. Some
    of the required information has now been supplied. After a single
    application and a pre-harvest interval of 28 days, maximum residues
    were 0.05 mg/kg in maize kernels and 0.02 mg/kg in fresh maize plants
    used for feed. Higher dosage and repeated application led to residues
    of bromophos-ethyl up to 0.39 mg/kg in rape seed and 0.8 mg/kg in
    green rape at 28 and 21 days respectively after the last treatment.
    Further residue data have been supplied for carrots and Brussels
    sprouts. In the case of Brussels sprouts, some data are also available
    on residue levels after trimming, washing and cooking.

         Experimental oral application of high doses of bromophos-ethyl to
    a sheep led to high residues in body fat but considerably lower levels
    in muscle, kidney, liver, brain and spleen. Fourteen days after
    dipping sheep in washes containing 0.05% bromophos-ethyl, residues in
    back, renal and omental fat were below 2 mg/kg.

         The dipping of dairy cows at recommended rates resulted in a
    maximum residue of 1.13 mg/kg in butter fat after one day. This fell
    to 0.24-0.47 mg/kg after 3 days, 0.02-0.04 mg/kg after 6-7 days and
    0.01 mg/kg or below after 8 days. Cows in one area are not treated
    simultaneously, and it can be assumed that milk from a treated herd
    will be diluted about fourfold or more with milk from untreated cows
    (see also section 2.5 of the 1971 Joint Meeting Report, FAO/WHO,
    1972). A maximum residue limit of 0.2 mg/kg for milk and milk products
    (fat basis) should therefore be adequate (see also coumaphos,
    Evaluations). Maximum residues in body fat amounted 0.24 mg/kg three
    days after spraying.

         Although same of the information required by the 1972 Joint
    Meeting has been submitted further information which is listed below
    is still desirable to enable tolerances to be recommended for further


         As an ADI has now been allocated, the previously recommended
    temporary tolerances are confirmed as maximum residue limits, with the
    exception of the limit for whole milk (previously 0.02 mg/kg) which is
    deleted and replaced as shown below. The following additional maximum
    residue limits, determined and expressed as bromophos-ethyl, are



         Commodity                                 (mg/kg)

         Fat of meat of sheep                       3

         Milk and milk products (fat basis)         0.2

         Maize (kernels and fodder)                 0.05


    DESIRABLE (in addition to the information as listed in FAO/WHO,
    1973a, p. 43)

         1.   Residue data from supervised trials on cereals other than
              maize, on cotton and on fruit and vegetables after repeated
              application where this forms a part of good agricultural

         2.   Further information on use patterns including data on rates,
              frequencies of application, and pre-harvest intervals,
              especially on black and red currants, peaches, strawberries,
              blackberries or raspberries, Brussels sprouts, cauliflower,
              kale, sugar beets and sugar beet tops, together with residue
              data where appropriate.

         3.   Further information on the fate of residues in vegetables
              after cooking, especially carrots and spinach.


    CCPR. (1975) Report of the 8th session of the Codex Committee on
    Pesticide Residues, CL 1975/13; August 1975

    Celamerck. (1975a) Bromophos-äthyl, Rückstandsdaten in Mais.
    (Unpublished data sent to FAO)

    Celamerck. (1975b) Bromophos-äthyl, Rückstandsdaten in Rape.
    (Unpublished data sent to FAO)

    Eichler, D. (1972) Bromophos and bromophos-ethyl residues. Residue
    Reviews, 41:65-112. F. A. Gunther, Ed., Springer Verlag, New York -
    Heidelberg - Berlin

    Leuschner, F. (1975) The influence of bromophos-ethyl-batch 4/73
    called "B-Athyl" on ascorbic acid values and cholinesterase activity
    in rats and guinea pigs. Unpublished report from the Laboratorium für
    Pharmakologie und Toxikologie, Hambourg, FRG, submitted to the World
    Health Organization by Celamerck GmbH & Co. KG Ingelheim am Rhein

    RIV. (1970) Rijksinstituut voor de Volksgesondheid, No. 27/70 Tox-RoB,
    Residuen van bromofos-ethyl in spruitkool (maart 1970)

    RIV. (1971a) Rijksinst. v.d. Volksgezondheid, No. 86/71 Tox-RoB,
    Bestrijding van weitelvlieg met bromofos-ethyl (juni 1971)

    RIV. (1971b) Rijksinst. v.d. Volksgezondheid, No. 125/71 Tox-RoB,
    Residuen van enige orjanofosfor insekticiden in spruitkool (august

    RIV. (1974) Rijksinst. v.d. Volksgezondheid, No. 61/74 Tox-RoB,
    Residuen van bestrijdingsmiddelen in groente en fruit in diverse
    stadia van de huishondelijke bereiding (april 1974)

    TVL. (1975) Tasman Vaccine Laboratory Limited. Letter dealing with
    bromophos-ethyl residues in sheep; 22 September 1975 (Unpublished)

    Wollongbar Agricultural Research Station (N.S.W.), Dep. of
    Agriculture. (1969) (Unpublished data on bromophos-ethyl residues in
    butter of cows [after Nexagan(R)-dipping], 31.3.69)

    See Also:
       Toxicological Abbreviations
       Bromophos-ethyl (WHO Pesticide Residues Series 2)
       Bromophos-ethyl (Pesticide residues in food: 1977 evaluations)