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 CHLORPYRIFOS RESIDUES Explanation Chlorpyrifos was reviewed by the Joint Meetings of 1972, 1974, 1975, 1977, 1981 and 1982.1 An acceptable daily intake (ADI) of 0-0.01 mg/kg b.w. was estimated by the 1982 Meeting and MRLs on a number of food commodities, including grapes, are under consideration in the Codex Committee on Pesticide Residues (CCPR). Residues data following the preharvest application of chlorpyrifos to grapes to provide protection to mature, drying and dried vine fruit have been evaluated. RESIDUES IN FOOD AND THEIR EVALUATION USE PATTERN Ripe grapes grown for the production of dried fruit are attacked by Ephestia figulillela, Drosophila spp. and Carpophilus spp. It has been shown that preharvest sprays with chlorpyrifos can reduce damage. Recommended use is to spray the ripening fruit with a 200 mg/kg solution (20 g a.i. in 100 litres of water) 21 days prior to harvest (McDonald et al. 1983). RESIDUES RESULTING FROM SUPERVISED TRIALS Grapes Grape vines in Victoria, Australia, were sprayed once with Lorsban 50 EC (50 percent chlorpyrifos) during early maturation. Application rates of 428.5 g, 43 g and 17.0 g a.i./100 litres of water were used to achieve target residues of 50, 5 and 2 mg/kg. Actual initial residues were higher than expected at 73.8, 9.5 and 2.7 mg/kg. These initial deposits vary with weight of fruit, volume of spray required for complete coverage and retention by the surface of the fruit. Fruit was harvested on four occasions (0, 8, 36 and 51 days after spraying) during the maturation period. Sampled fruit was subsampled for analysis and dried for 21 days (the normal commercial drying period) and again sampled for analysis. Table 1 shows the results obtained (Sweden 1983). 1 See Annex 2 for FAO and WHO documentation. Table 1 Residues of Chlorpyrifos in Sultanas Application rate Preharvest interval Residue (mg/kg) (mg/kg spray concen.) (days) at harvest on dried fruit 21 days postharvest 4 285 0 73.8 68 8 44.6 38 36 7 7 51 4.7 9 430 0 9.4 9 8 5.4 4.4 36 1.0 1.1 51 0.8 0.9 170 0 2.7 1.6 8 1.1 1.3 36 0.23 0.4 51 0.2 0.3 Table 2 Chlorpyrifos Residues in Food Commodities, Sweden Number of samples with residues within Maximum Food Origin No. of samples given ranges (mg/kg) residue analysed <0.05 0.05-0.12 0.13-0.25 >0.25 (mg/kg) Apple Sweden 286 286 Import 917 895 17 3 2 0.64 Cabbage Sweden 71 71 Import 174 173 1 0.052 Carrot Sweden 209 209 Import 217 215 1 1 0.17 Celery Sweden 8 8 Import 42 35 1 6 0.77 Cucumber Sweden 227 227 Import 353 352 1 0.060 Grapes Import 327 315 6 4 2 0.52 Grapefruit Import 148 138 6 4 0.52 Iceberg Sweden 112 112 lettuce Import 200 287 3 0.090 Lemon Import 164 163 1 0.13 Mandarin Import 292 283 8 1 0.29 Oranges Import 622 572 40 6 4 1.1 Pear Sweden 109 109 Import 455 454 1 0.23 Table 2 (con't) Number of samples with residues within Maximum Food Origin No. of samples given ranges (mg/kg) residue analysed <0.05 0.05-0.12 0.13-0.25 >0.25 (mg/kg) Pepper Import 206 198 2 4 2 0.38 (sweet) Tomato Sweden 205 205 Import 500 496 4 0.10 Insect control has been achieved at the rate of 170 mg/kg applied 21 days before harvesting; this corresponds to a residue of chlorpyrifos at harvest of approximately 0.5 mg/kg. There is less loss of chlorpyrifos after harvest and there may be an increase in actual residue content (mg/kg) owing to loss of weight of fruit on drying. The treatment registered as good agricultural practice is somewhat higher than the minimum treatment tested (but not as high as the next rate). RESIDUES IN FOOD IN COMMERCE OR AT CONSUMPTION From 1 January 1981 to 30 April 1983 monitoring of 8 654 samples of food commodities in Sweden gave the results shown in Table 2 (Sweden 1983). The Swedish MRLs are 0.2 for fruit and vegetables, 0.05 mg/kg for potatoes and 0.5 mg/kg for citrus fruits. APPRAISAL The Meeting considered data from trials in which chlorpyrifos was applied preharvest to grapes to provide protection to mature, drying and dried vine fruit. Residues data on the dried fruit enabled the Meeting to estimate an MRL for dried vine fruit (based on supervised trials on sultanas) of 2 mg/kg. This was considered suitable for the establishment of an MRL. The Meeting confirmed that the residue should be defined as the parent compound only. RECOMMENDATIONS The MRL listed below is recommended. It refers to chlorpyrifos. Metabolites are not included. Commodity MRL (mg/kg) Dried vine 2 fruit. REFERENCES - RESIDUES McDonald, G., Buchanan, G.A. & Griffiths, G.R. Insecticide 1983 application and degradation in sultana grapes grown for drying. Pestic. Sci. 14:528-536. Sweden. Data on chlorpyrifos residues submitted to FAO. (Unpublished) 1983
See Also: Toxicological Abbreviations Chlorpyrifos (ICSC) Chlorpyrifos (WHO Pesticide Residues Series 2) Chlorpyrifos (WHO Pesticide Residues Series 5) Chlorpyrifos (Pesticide residues in food: 1977 evaluations) Chlorpyrifos (Pesticide residues in food: 1981 evaluations) Chlorpyrifos (Pesticide residues in food: 1982 evaluations) Chlorpyrifos (JMPR Evaluations 1999 Part II Toxicological)