COUMAPHOS JMPR 1978
Explanation
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.
RESIDUES IN FOOD AND THEIR EVALUATION
USE PATTERNS
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
used
(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.
RESIDUES RESULTING FROM SUPERVISED TRIALS
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.
RESIDUES IN FOOD IN COMMERCE OR AT CONSUMPTION
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.
NATIONAL MRLs REPORTED TO THE MEETING
The following maximum residue limits are in force in
Australia.
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
APPRAISAL
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.
RECOMMENDATIONS
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
REFERENCES
Anonymous. Information on coumaphos from Australia.
(1978)
Anonymous. Information on coumaphos from the Netherlands.
(1978)
FAO/WHO. 1968 evaluations of some pesticide residues in food.
(1969)
FAO/WHO. 1972 evaluations of some pesticide residues in food.
(1973)
FAO/WHO. 1975 evaluations of some pesticide residues in food.
(1976)
Tuinstra, I. De vitscheiding van coumaphos en zign metabolieten
(1976) na gebraile van coumaphos tegen schurft,
Rykszuivelstation, report 2e series no. 151, May
1976.
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)