PESTICIDE RESIDUES IN FOOD - 1983 Sponsored jointly by FAO and WHO EVALUATIONS 1983 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 Geneva, 5 - 14 December 1983 Food and Agriculture Organization of the United Nations Rome 1985 DIFLUBENZURON RESIDUES Explanation Diflubenzuron was first evaluated in 1981.1 The attention of the Meeting was drawn to the fact that the data supporting the 1981 estimates for maximum residue levels (MRLs) in Brussels sprouts, cabbage and plums had been inadvertently omitted from the 1981 evaluations. This addendum corrects that error. RESIDUES IN FOOD AND THEIR EVALUATION RESIDUES RESULTING FROM SUPERVISED TRIALS Two supervised trials on Brussels sprouts in 1976 in the Netherlands resulted in residues of up to approximately 0.3 mg/kg in harvested crops 58 days after treatment (see Table 1, Philips-Duphar 1978a). Trials on cabbage in the Netherlands in 1974 and the Federal Republic of Germany in 1975 showed that initial residues in Savoy cabbage of up to 0.7 mg/kg declined to 0.1 mg/kg or less in 28 days. Similarly, in oxheart cabbage, initial residues of up to 3 mg/kg declined to about 0.1 mg/kg or less in 28 days (see Table 1, Philips-Duphar 1976). In Brussels sprouts, the analytical method gave a mean recovery of 88 percent over a range of diflubenzuron from 0.02 mg/kg to 2 mg/kg. Mean recoveries for Savoy cabbage were 92 percent and for oxheart cabbage 85 percent, both over a range of 0.03 mg/kg to 2 mg/kg. The limit of determination was from 0.02 mg/kg for Brussels sprouts to 0.05 mg/kg for cabbage. A single trial on Victoria plums in 1977 in the Netherlands showed a residue of less than 0.1 mg/kg 27 days after treatment. Mean recoveries with the analytical method were 98 percent over a range of 0.01 mg/kg (the limit of determination) to 2 mg/kg of diflubenzuron (see Table 1, Philips-Duphar 1977). 1 See Annex 2 for FAO and WHO documentation. Table 1 Diflubenzuron residues in Brussels sprouts, cabbage and plums Interval from application Residue Crop Treatment to sampling (days) (mg/kg) Brussels sprouts 0.001% 15 0.07 (Netherlands) conc'n spray 58 <0.02 1976 0.01% 16 0.33 conc'n spray 58 0.31 Brussels sprouts 250 g a.i./ha 7 0.94 (UK) 14 0.81 19781 21 0.6 28 0.68 Savoy cabbage 25 g a.i. in 0 0.7, 0.24, 0.39, 0.23 (Netherlands) 2 500 l water/ 1974 ha 7 0.13, 0.22, 0.22, 0.08, 14 0.21, 0.17, 0.10, 0.05 28 0.03,<0.03, <0.03, <0.03 0 0.22, 0.45, 0.14,<0.03 7 0.08, 0.20, 0.10, 0.07 14 0.06, 0.09, 0.10, 0.03 28 0.06, 0.11, 0.08, 0.06 Oxheart 100 g a.i. in 0 1.8, 2.9, 2.0, 2.9 Cabbage 1 000 l 7 0.9, 0.6, 1.2, 0.9 (Germany) water/ha 14 0.4, 0.3, 0.5, 0.4 1975 28 0.07, 0.06, 0.1, 0.1 Plums 0.02% 27 0.02 (Netherlands ) conc'n 1976 0.04% 27 0.06 conc'n 1 Source: Philips-Duphar 1978b. APPRAISAL The Meeting reviewed the data on residues in mushrooms in the 1981 evaluations and concluded that an estimated MRL of 0.1 mg/kg was more appropriate than the figure of 0.2 mg/kg previously estimated. It was recognized, however, that at the highest rate of application studied there was a possibility the 0.1 mg/kg might be marginally exceeded at the first cropping. The Meeting noted that the data supporting the 1981 estimates for MRLs in Brussels sprouts, cabbage and plums had been accidentally omitted from the 1981 evaluations. On reviewing these data, the Meeting concluded that they would not support the MRL for plums estimated in 1981 and recommended that it be withdrawn until further data become available. REFERENCES- RESIDUES Philips-Duphar Report on residues of diflubenzuron in cabbage, 1976 Netherlands 1974, Germany 1975. (Unpublished) Philips-Duphar Report on residues of diflubenzuron in plums, 1977 Netherlands 1976. (Unpublished) Philips-Duphar Report on residues of diflubenzuron in Brussels 1978a sprouts, Netherlands 1976. (Unpublished) Philips-Duphar Report on residues of diflubenzuron in Brussels 1978b sprouts, UK 1978. (Unpublished)
See Also: Toxicological Abbreviations Diflubenzuron (EHC 184, 1996) Diflubenzuron (HSG 99, 1995) Diflubenzuron (Pesticide residues in food: 1981 evaluations) Diflubenzuron (Pesticide residues in food: 1984 evaluations) Diflubenzuron (Pesticide residues in food: 1985 evaluations Part II Toxicology) Diflubenzuron (JMPR Evaluations 2001 Part II Toxicological)