Normativa UEMay. 4, 2012
UE: autoridad alimentaria revisa límites máximos de residuo para flufenacet
Flufenacet was included in Annex I to Directive 91/414/EEC on 01 January 2004, which is before the entry into force of Regulation (EC) No 396/2005 on 02 September 2008. EFSA is therefore required to provide a reasoned opinion on the review of the existing MRLs for that active substance in compliance with Article 12(2) of the afore mentioned regulation. In order to collect the relevant pesticide residues data, EFSA asked France, as the designated rapporteur Member State (RMS), to complete the Pesticide Residues Overview File (PROFile). The requested information was submitted to EFSA on 20 May 2009 and, after having considered several comments made by EFSA, the RMS provided on 22 January 2010 a revised PROFile.
Based on the conclusions derived in the framework of Directive 91/414/EEC under the supervision of the European Commission and the additional information provided by the RMS, EFSA issued on 25 October 2011 a draft reasoned opinion that was circulated to Member State experts for consultation. Comments received by 06 January 2012 were considered for finalisation of this reasoned opinion.
The following conclusions are derived.
The toxicological profile of flufenacet was evaluated in the framework of Directive 91/414/EEC, which resulted in an ADI of 0.005 mg/kg bw/d and an ARfD of 0.017 mg/kg bw/d.
Primary crop metabolism of flufenacet was investigated for pre-emergence treatment on cereals and pulses & oilseeds in the DAR using fluorophenyl-U-14C labelled flufenacet. A study for pre-emergence treatment on pulses & oilseeds was conducted using thiadiazole-2-14C labelled flufenacet. In addition pre-emergence and foliar treatment metabolism studies on root vegetables and cereals (foliar treatment only) using fluorophenyl-U-14C labelled flufenacet were evaluated by the RMS, after the peer review was completed. The metabolism of the thiadiazole moiety of flufenacet is considered to be adequately understood on the basis of the available studies. It is also concluded that metabolites containing the thiadone moiety are not relevant and should not be included in the residue definition. The metabolism of the fluorophenyl moiety of flufenacet results in a number of metabolites which all have the N-isopropyl-4-flurophenyl moiety. A ‘total residue’ approach has been proposed and the current residue definition for risk assessment and enforcement is the sum of all compounds containing the N-fluorophenyl-N-isopropyl moiety expressed as flufenacet equivalent. A validated analytical method for enforcement of the residue definition in food of plant origin is available, with an overall LOQ of 0.05 mg/kg in dry, high fat and high water commodities. Further validation of the analytical method in acidic commodities is still required.
Regarding the magnitude of residues in crops, a sufficient number of supervised residues trials are available for all the crops for which GAPs are supported in the framework of this review. These data allowed EFSA to estimate the expected residue concentrations in these plant commodities and to derive MRLs. The MRLs derived for acidic commodities are tentative as further validation of the analytical method for these matrices is still required.
Studies on the hydrolytic degradation of flufenacet and studies on the magnitude of residues in processed commodities of maize and soya bean indicate that processing is not expected to have a significant impact on the composition or magnitude of residues in matrices of plant origin. Specific processing factors for enforcement of processed commodities are therefore not proposed. Further processing studies are not required as they are not expected to affect the outcome of the risk assessment. However, if more robust processing factors were to be required by risk managers, in particular for enforcement purposes, additional processing studies would be needed.
Occurrence of flufenacet residues in rotational crops was investigated during the peer review. A study showed that metabolism in primary and rotational crops is comparable and significant residues in rotational crops are not expected, provided that flufenacet is applied according to the GAPs supported in the framework of this review.
Based on the uses reported by the RMS, significant intakes were calculated for ruminants, poultry and pigs. Metabolism studies on lactating goats and laying hens using fluorophenyl-U-14C, flufenacet oxalate and thiadiazole-2-14C labelled flufenacet were reported. In consideration of the available animal metabolism studies the residue definition proposed for plants is also proposed for animal matrices. A validated analytical method for enforcement of the residue definition in food of animal origin is also available, with a LOQ of 0.01 mg/kg in milk, 0.02 mg/kg for liver and 0.05 mg/kg for kidney, fat, muscle and eggs. On the basis of the animal metabolism studies it is also concluded that, after exposure to the maximum dietary burden (about 200 times lower than the dose level in the metabolism studies), residue levels in livestock commodities are expected to remain below the LOQ. Hence, no livestock feeding study is needed and MRLs and risk assessment values for the relevant commodities in ruminants and poultry can be established at the LOQ level.
Chronic consumer exposure resulting from the authorised uses reported in the framework of this review was calculated using revision 2 of the EFSA PRIMo and compared with the toxicological reference value derived for flufenacet. The highest chronic exposure was calculated for the WHO cluster diet B, representing 24.6 % of the ADI and the highest acute exposure was calculated for potatoes, representing 99.5% of the ARfD.
Based on the above assessment, EFSA does not recommend inclusion of this active substance in Annex IV to Regulation (EC) No 396/2005. MRL recommendations were derived in compliance with the decision tree reported in Appendix D (see table below for a summary). All MRL values listed as ‘Recommended’ in the table are sufficiently supported by data and therefore proposed for inclusion in Annex II to the Regulation. The remaining MRL values listed in the table are not recommended for inclusion in Annex II because they require further consideration by risk managers (see table footnotes for details). In particular, certain tentative MRLs still need to be confirmed by an analytical method for enforcement of flufenacet residues in acidic commodities. If this data gap is not addressed in the future, Member States are recommended to withdraw or modify the relevant authorisations at national level.
It is also highlighted that the residue definition proposed for enforcement purposes might be undesirable as it requires the use of a single residue method hydrolysing all metabolites to the common moiety.
EFSA therefore recommends investigating the possibility of including the following metabolites in a multi-residue method: flufenacet oxalate, flufenacet sulfonic acid, flufenacet thioglycolate sulfoxide, flufenacet sulfinyl lactic acid glucoside, flufenacet cysteine conjugate and flufenacet sulfanyl lactic acid glucoside.