PESTICIDE RESIDUES IN FOOD - 1984
Sponsored jointly by FAO and WHO
Data and recommendations of the joint meeting
of the FAO Panel of Experts on Pesticide Residues
in Food and the Environment and the
WHO Expert Group on Pesticide Residues
Rome, 24 September - 3 October 1984
Food and Agriculture Organization of the United Nations
Phoxim was evaluated by the Joint Meeting in 1982 and 1983. 1/
Information was desired by the 1983 JMPR on residues in milk and fat
from treatment of cattle, residues in fat from treatment of pigs and
also information on good agricultural practice in use of phoxim on
The Meeting has received results from supervised trials carried
out in Mexico on sweet corn in accordance with registered use in
Mexico. A report was also made available to the Meeting on two
experiments carried on in the Netherlands on residues in milk from
dairy cattle treated with phoxim.
RESIDUES IN FOOD AND THEIR EVALUATION
Residues Resulting from Supervised Trials
Sweet corn in Mexico was treated with phoxim dust at planting at
rate of 1.25 kg/ha. In other trials, the crop was also treated with
phoxim granules 0.5 kg/ha about 1.5 months after first treatment
(three whorls formed). No residue was detected in kernels or cob after
one treatment and residues up to 0.03 mg/kg were observed after two
applications (see Table 1) (Bayer, 1984a).
Phoxim is used against ectoparasites and mites on cattle, pigs
and sheep by spraying or dipping the animals. Two experiments were
carried out in The Netherlands for determining residues of phoxim and
its oxygen analogue in milk after dermal treatment of dairy cattle.
Each animal was sprayed with about 1 g phoxim solved in 2 l water
(500 mg/l). In experiment 1, five cows were treated once. Milk samples
were taken before treatment, 0.5 day after treatment and in the
morning and evening every day until 13 days after treatment. In
experiment 2 the same treatment was repeated after six days and
samples were taken one day before the last treatment and in the
morning and evening every day give days after the last treatment. Milk
from each cow was analysed separately.
1/ See Annex 2 for FAO and WHO documentation.
TABLE 1. Residues of Phoxim in Sweet Corn from Supervised Trials, Mexico
Days Days Residue
Dust powder Granular, between after last (mg/kg)
in furrow topical applications application
(rate a.i.) (rate a.i.) Kernels Cob
1.25 kg/ha 78-81 <0.01 <0.01
1.25 kg/ha 0.5 kg/ha 46-50 32-33 <0.01-0.02 <0.01-0.03
Note: Samples were also analysed for residues of the oxygen analogue but none was observed
(limit of determination for both compounds: 0.01 mg/kg).
TABLE 2. Residues in Milk from Cows Treated with Phoxim
Residues in milk from 5 cows after one dermal treatment with 1 g phoxim/2 l.
Days after treatment -0.5 0.5 1 1.5 2 2.5 3
Average content µg/l nd 54 18 10 2 nd nd
Range µg/l nd 40-80 10-20 8-10 nd-2 nd nd
Residues in milk from 5 cows after 2 dermal treatments (6-day interval) with 1 g phoxim/2 l.
Days after -1 0.5 1 1.5 2 2.5 3 3.5
Average 1 2 10 4 1 3 nd nd
Range µg/l nd-1 2-4 2-16 2-5 1-2 1-5 nd-1 nd
In experiment 1, maximum residue level of phoxim was observed
0.5 day after treatment. The residue level decreased very quickly and
samples taken 2.5 days after treatment contained no detectable
residue. In experiment 2, the maximum level was observed one day after
the last treatment and no residue was detected 3.5 days after last
treatment (see Table 2) (Bayer, 1984b).
Samples were also analysed for residues of the oxygen analogue,
which was not detected. Limits of determination for phoxim and the
analogue were 0.5 µg/l.
Information was received on supervised trials on sweet corn and
on investigations of residues in milk from cattle after dermal
treatments with phoxim.
Supervised trials were carried on in Mexico with applications in
accordance with good agricultural practice in that country. Phoxim was
applied as soil treatments at planting at a rate of 1.25 kg/ha and
also 1.5 months after planting at 0.5 kg/ha. When treated twice,
residues of phoxim up to 0.03 mg/kg were found in cob and kernels, but
no oxygen analogue was detected.
In experiments in The Netherlands, dairy cattle were treated once
and twice with phoxim by spraying each animal with 1 g phoxim at a
concentration of 500 mg/l. Residues of phoxim in milk reached their
maximum concentrations 0.5-1 day after application and decreased
rapidly, so that no residues were detectable 3-4 days after treatment.
The limit of determination was 0.5 µg/l milk.
The following estimated maximum residue levels are recommended as
MRLs, which need not be exceeded when phoxim is used according to GAP.
The limits refer only to the parent compound.
Commodity MRL Intervals after last treatment
(mg/kg) on which recommendations are
*Sweet corn 0.05 ** 30
*Milk 0.01 ** 3
* New MRL
** Level at or about limit of determination.
Bayer Report on supervised trials on sweet corn in Mexico.
1984a Submitted by Bayer AG to FAO. (Unpublished)
Bayer Report on supervised trials on milk of dairy cattle in The
1984b Netherlands. Submitted by Bayer AG to FAO. (Unpublished)