COUMAPHOS         JMPR 1978


         This insecticide was first evaluated in 1968 (FAO/WHO, 1969b)
    at which time a temporary acceptable daily intake (ADI) and
    temporary tolerances, now maximum residue limits (MRL), were
    recommended. The residue limit were replaced by revised and figures
    in 1972 (FAO/WHO, 1973b) and the temporary ADI was extended for 3
    more years. The temporary ADI was again extended in 1975 (FAO/WHO,
    1976b) with re-evaluation required in 1978. There were no
    requirements for further information on residues or uses.

         Contributions from Australia and the Netherlands were
    available to the Meeting providing information on use patterns,
    residues in food in commerce or at consumption, and maximum residue
    limits in effect in those countries.



         In Australia and many other countries, coumaphos is used to
    control ectoparasites on cattle and sheep.

         Specific uses. In Australia formulations ranging from a 150
    g/l emulsifiable concentrate to a 500 g/kg wettable powder, are

         (i)  in cattle dips and cattle sprays, at concentrations of
              25g-85g/100l. (0.025-0.085%) to control tick and louse
              species. Cattle are either withheld from slaughter for 3
              days or withheld from milking for 7 days after treatment;

         (ii) in sheep dips, at concentrations of 25g-50g/100l
              (0.025-0.05%) to control blowfly, louse, or ked
              species. Sheep are withheld from slaughter for 7
              days after treatment.

         It is currently being considered for use as a spray on pigs to
    control mange.

         In the Netherlands, coumaphos is used for ectoparasite control
    on cattle, sheep, pigs, goats and horses at concentrations of
    20-50g/100l in sprays, washes, or dips or up to 25g/animal or pigs
    as a powder. Treatments are repeated at various intervals for
    different parasites ranging from 8 to 14 days. The pre-slaughter
    interval is 14 days.


    On animals

         Data were available from the Netherlands on residues in milk
    from application to cows at a rate of 1.5g/cow (50% wp) for each of

    2 treatments at 8 day intervals. Milk residues in mg/kg at intervals
    (hours) after the last application were: 6 hours: 0.21-0.27, mean =
    0.25; 18 hours: 0.17-0.26, mean = 0.21; 30 hours: 0.11-0.16,
    mean = 0.13; 42 hours: < 0.1 (5 replicates). The oxygen analogue was
    also determined in each sample and found to be < 0.1 mg/kg which
    is the limit of determination of the method.


         In a market basket survey in Australia made in 1970 coumaphos
    was not determined specifically, but the total organophosphorus
    residues found did not exceed 0.5 mg/kg in any of the foods
    examined; in all, some 240 samples ware examined and only 32
    contained any residues, of which only 3 exceeded 0.2 mg/kg.
    Residues of coumaphos have not been reported in the raw produce
    (meat, grain, dairy products, fruit and vegetables) examined
    continuously in routine national surveys.


         The following maximum residue limits are in force in

    TABLE 1. Australian maximum residue limits

              Commodity                               Limit, mg/kg

              Fat of cattle and poultry               1
              Fat of sheep, pigs, goats               0.5
              Milk and milk products (fat basis)      0.1
              Eggs                                    0.05

         There are no national MRLs at present, but the following MRLs
    are under consideration for the Netherlands.

    TABLE 2. MRLs under consideration in the Netherlands

              Commodity                               Limit, mg/kg

              Milk and milk products                  0.5

              Meat and meat products of cattle        1

              Other meat and meat products            0.5

              Meat of poultry                         0.5

              Egg and egg products                    0.5

              Other commodities                       0.02*

    * At or about the limit of determination


         The U.S. subsidiary of the manufacturer indicated that there
    would be no further submissions of residue data as the major
    requirements were fulfilled.

         The previously recommended temporary MRL of 0.5 mg/kg for milk
    on a fat basis is replaced by the equivalent recommendation of 0.02
    mg/kg for the whole milk. The MRLs apply to the sum of coumaphos
    and its oxygen analogue.


         The following recommendation replaces the equivalent MRL
    previously recommended. MRLs apply to the sum of coumaphos and its
    oxygen analogue.

              Commodity                     MRL, mg/kg

              Milk (whole)                  0.02


    Anonymous.     Information on coumaphos from Australia.

    Anonymous.     Information on coumaphos from the Netherlands.

    FAO/WHO.       1968 evaluations of some pesticide residues in food.

    FAO/WHO.       1972 evaluations of some pesticide residues in food.

    FAO/WHO.       1975 evaluations of some pesticide residues in food.

    Tuinstra, I. De vitscheiding van coumaphos en zign metabolieten
    (1976)         na gebraile van coumaphos tegen schurft,
                   Rykszuivelstation, report 2e series no. 151, May

    See Also:
       Toxicological Abbreviations
       Coumaphos (ICSC)
       Coumaphos (FAO/PL:1968/M/9/1)
       Coumaphos (WHO Pesticide Residues Series 2)
       Coumaphos (WHO Pesticide Residues Series 5)
       Coumaphos (Pesticide residues in food: 1980 evaluations)
       Coumaphos (Pesticide residues in food: 1983 evaluations)
       Coumaphos (Pesticide residues in food: 1990 evaluations Toxicology)