PESTICIDE RESIDUES IN FOOD - 1984 Sponsored jointly by FAO and WHO EVALUATIONS 1984 The monographs 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 Rome 1985 PHOXIM Explanation 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 vegetables. 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 Maize 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 Application 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 (4 experiments) 1.25 kg/ha 0.5 kg/ha 46-50 32-33 <0.01-0.02 <0.01-0.03 (4 experiments) 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 Experiment 1: 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 Experiment 2: 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 last treatment Average 1 2 10 4 1 3 nd nd content µg/l 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. APPRAISAL 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. RECOMMENDATIONS 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 based (days) *Sweet corn 0.05 ** 30 *Milk 0.01 ** 3 * New MRL ** Level at or about limit of determination. REFERENCES 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)
See Also: Toxicological Abbreviations PHOXIM (JECFA Evaluation) Phoxim (Pesticide residues in food: 1982 evaluations) Phoxim (Pesticide residues in food: 1983 evaluations) Phoxim (Pesticide residues in food: 1984 evaluations)