CONCLUSION ON PESTICIDES PEER REVIEW

Transcription

1 CONCLUSION ON PESTICIDES PEER REVIEW APPROVED: 19 February 2016 PUBLISHED: 07 March 2016 doi: /j.efsa Peer review of the pesticide risk assessment of the active substance mesotrione Abstract European Food Safety Authority (EFSA) The conclusions of the European Food Safety Authority (EFSA) following the peer review of the initial risk assessments carried out by the competent authorities of the rapporteur Member State the United Kingdom and co-rapporteur Member State Belgium for the pesticide active substance mesotrione are reported. The context of the peer review was that required by Commission Implementing Regulation (EU) No 844/2012. The conclusions were reached on the basis of the evaluation of the representative use of mesotrione as a herbicide on maize. The reliable end points, appropriate for use in regulatory risk assessment are presented. Missing information identified as being required by the regulatory framework is listed. Concerns are identified. European Food Safety Authority, 2016 Key words: mesotrione, peer review, risk assessment, pesticide, herbicide Requestor: European Commission Question number: EFSA-Q Correspondence: pesticides.peerreview@efsa.europa.eu EFSA Journal 2016;14(3):4419

2 Suggested citation: EFSA (European Food Safety Authority), Conclusion on the peer review of the pesticide risk assessment of the active substance mesotrione. EFSA Journal 2016;14(3):4419, 103 pp. doi: /j.efsa ISSN: European Food Safety Authority, 2016 Reproduction is authorised provided the source is acknowledged. The EFSA Journal is a publication of the European Food Safety Authority, an agency of the European Union. 2 EFSA Journal 2016;14(3):4419

3 Summary Commission Implementing Regulation (EU) No 844/2012 (hereinafter referred to as the Regulation ) lays down the procedure for the renewal of the approval of active substances submitted under Article 14 of Regulation (EC) No 1107/2009. The list of those substances is established in Commission Implementing Regulation (EU) No 686/2012. Mesotrione is one of the active substances listed in Regulation (EU) No 686/2012. In accordance with Article 1 of the Regulation, the rapporteur Member State (RMS), the United Kingdom, and co-rapporteur Member State (co-rms), Belgium, received an application from Syngenta Crop Protection AG for the renewal of approval of the active substance mesotrione. Complying with Article 8 of the Regulation, the RMS checked the completeness of the dossier and informed the applicant, the co-rms (Belgium), the European Commission and the European Food Safety Authority (EFSA) about the admissibility. The RMS provided its initial evaluation of the dossier on mesotrione in the renewal assessment report (RAR), which was received by EFSA on 23 February In accordance with Article 12 of the Regulation, EFSA distributed the RAR to the Member States and the applicant, Syngenta Crop Protection AG, for comments on 17 April EFSA also provided comments. In addition, EFSA conducted a public consultation on the RAR. EFSA collated and forwarded all comments received to the European Commission on 18 June Following consideration of the comments received on the RAR, it was concluded that additional information should be requested from the applicant, and that EFSA should conduct an expert consultation in the areas of mammalian toxicology, residues, environmental fate and behaviour and ecotoxicology. In accordance with Article 13(1) of the Regulation, EFSA should adopt a conclusion on whether mesotrione can be expected to meet the approval criteria provided for in Article 4 of Regulation (EC) No 1107/2009 of the European Parliament and of the Council. The conclusions laid down in this report were reached on the basis of the evaluation of the representative use of mesotrione as a herbicide on maize, as proposed by the applicant. Full details of the representative uses can be found in Appendix A of this report. The use of mesotrione according to the representative use proposed at EU level results in a sufficient herbicidal efficacy against the target weeds. In the area of identity, physical/chemical/technical properties and methods of analysis, a data gap was identified for specifying two of the significant impurities on dry weight basis. Data gaps were identified for validation data of methods used in data generation. Regarding the mammalian toxicology area, a number of data gaps were identified. The toxicological relevance of individual impurities present in the technical specification in comparison with the toxicity profile of mesotrione needs to be addressed. Interspecies comparative in vitro metabolism should be conducted to identify at least potentially unique human metabolites to mesotrione. As the genotoxic potential of metabolite AMBA could not be ruled out due to positive results obtained in an in vitro cytogenetic assay, and no in vivo genotoxicity testing was performed, a critical area of concern has been identified regarding consumer risk assessment; repeated dose toxicity would also have to be addressed for this metabolite. Mesotrione is proposed to be classified as Repr. 2 for development by the peer review (in contrast with the harmonised classification according to CLP Regulation) and adverse effects were observed on endocrine organs. Therefore, according to the interim provisions of Annex II, point of Regulation (EC) No 1107/2009 concerning human health, mesotrione may be considered to have endocrine disrupting properties. As no study is available to investigate a potential ED mode of action, a general data gap has been identified such as level 2 and 3 indicated in the OECD Conceptual Framework to address this issue; this was identified as another critical area of concern. The consumer dietary risk assessment could not be finalised with regard to products of animal origin considering the requested clarification of the genotoxic potential and the toxicological profile of AMBA. Furthermore, the consumer risk assessment from consumption of drinking water could not be finalised whilst the nature of residues in drinking water following water treatment had not been addressed. 3 EFSA Journal 2016;14(3):4419

4 A data gap was also identified for the determination of the residues in pollen and bee products for human consumption. Enough information was available to finalise the exposure assessment in the environment. Nevertheless, a data gap has been identified for the applicant to address the substances of potential toxicological concern that could be derived from mesotrione and its metabolites under drinking water treatment procedure conditions to assess if the approval criteria in Article 4 of Regulation (EC) No 1107/2009 are satisfied. In the area of ecotoxicology, a data gap and a critical area of concern were identified to further address the long-term risk for wild mammals. A data gap was identified to further refine the risk to aquatic organisms in the scenarios R2, R3, and R4. Data gaps were also identified for bees to provide information to further assess the risk to adult honeybees and honeybee larvae from exposure via guttation and via consumption of contaminated water. Effects on HPG development should be considered. Furthermore additional data would be needed to assess the risk to honeybees for relevant metabolites in pollen and nectar. The risk to non-target terrestrial plants was low with mitigation measures. A data gap was also identified to further address the sensitivity to mesotrione of dicotyledonous and monocotyledonous plant species. 4 EFSA Journal 2016;14(3):4419

5 Table of contents Abstract... 1 Summary... 3 Background... 6 The active substance and the formulated product... 8 Conclusions of the evaluation Identity, physical/chemical/technical properties and methods of analysis Mammalian toxicity Residues Environmental fate and behaviour Ecotoxicology Overview of the risk assessment of compounds listed in residue definitions triggering assessment of effects data for the environmental compartments Data gaps Particular conditions proposed to be taken into account to manage the risk(s) identified Concerns Issues that could not be finalised Critical areas of concern Overview of the concerns identified for each representative use considered References Abbreviations Appendix A List of end points for the active substance and the representative formulation Appendix B Used compound code(s) EFSA Journal 2016;14(3):4419

6 Background Commission Implementing Regulation (EU) No 844/ (hereinafter referred to as the Regulation ) lays down the provisions for the procedure of the renewal of the approval of active substances, submitted under Article 14 of Regulation (EC) No 1107/ This regulates for the European Food Safety Authority (EFSA) the procedure for organising the consultation of Member States, the applicant(s) and the public on the initial evaluation provided by the rapporteur Member State (RMS) and/or co-rapporteur Member State (co-rms) in the renewal assessment report (RAR), and the organisation of an expert consultation where appropriate. In accordance with Article 13 of the Regulation, unless formally informed by the European Commission that a conclusion is not necessary, EFSA is required to adopt a conclusion on whether the active substance can be expected to meet the approval criteria provided for in Article 4 of Regulation (EC) No 1107/2009 within five months of the end of the period provided for the submission of written comments, subject to an extension of up to eight months where additional information is required to be submitted by the applicant(s) in accordance with Article 13(3). In accordance with Article 1 of the Regulation, the RMS the United Kingdom and co-rms Belgium received an application from Syngenta Crop Protection AG for the renewal of approval of the active substance mesotrione. Complying with Article 8 of the Regulation, the RMS checked the completeness of the dossier and informed the applicant, the co-rms (Belgium), the European Commission and EFSA about the admissibility. The RMS provided its initial evaluation of the dossier on mesotrione in the RAR, which was received by EFSA on 23 February 2015 (United Kingdom, 2015a). In accordance with Article 12 of the Regulation, EFSA distributed the RAR to the Member States and the applicant, Syngenta Crop Protection AG, for consultation and comments on 17 April EFSA also provided comments. In addition, EFSA conducted a public consultation on the RAR. EFSA collated and forwarded all comments received to the European Commission on 18 June At the same time, the collated comments were forwarded to the RMS for compilation and evaluation in the format of a reporting table. The applicant was invited to respond to the comments in column 3 of the reporting table. The comments and the applicant s response were evaluated by the RMS in column 3. The need for expert consultation and the necessity for additional information to be submitted by the applicant in accordance with Article 13(3) of the Regulation were considered in a telephone conference between EFSA, the RMS and co-rms on 5 August On the basis of the comments received, the applicant s response to the comments and the RMS s evaluation thereof, it was concluded that additional information should be requested from the applicant, and that EFSA should conduct an expert consultation in the areas of mammalian toxicology, residues, environmental fate and behaviour and ecotoxicology. The outcome of the telephone conference, together with EFSA s further consideration of the comments, is reflected in the conclusions set out in column 4 of the reporting table. All points that were identified as unresolved at the end of the comment evaluation phase and which required further consideration, including those issues to be considered in an expert consultation, were compiled by EFSA in the format of an evaluation table. The conclusions arising from the consideration by EFSA, and as appropriate by the RMS, of the points identified in the evaluation table, together with the outcome of the expert consultation and the written consultation on the assessment of additional information, where these took place, were reported in the final column of the evaluation table. A final consultation on the conclusions arising from the peer review of the risk assessment took place with Member States via a written procedure in January-February Commission Implementing Regulation (EU) No 844/2012 of 18 September 2012 setting out the provisions necessary for the implementation of the renewal procedure for active substances, as provided for in Regulation (EC) No 1107/2009 of the European Parliament and of the Council concerning the placing of plant protection products on the market. OJ L 252, , p Regulation (EC) No 1107/2009 of 21 October 2009 of the European Parliament and of the Council concerning the placing of plant protection products on the market and repealing Council Directives 79/117/EEC and 91/414/EEC. OJ L 309, , p EFSA Journal 2016;14(3):4419

7 This conclusion report summarises the outcome of the peer review of the risk assessment of the active substance and the representative formulation, evaluated on the basis of the representative use of mesotrione as a herbicide on maize, as proposed by the applicant. A list of the relevant end points for the active substance and the formulation is provided in Appendix A. In addition, a key supporting document to this conclusion is the peer review report (EFSA, 2016), which is a compilation of the documentation developed to evaluate and address all issues raised in the peer review, from the initial commenting phase to the conclusion. The peer review report comprises the following documents, in which all views expressed during the course of the peer review, including minority views, where applicable, can be found: the comments received on the RAR; the reporting table (10 August 2015); the evaluation table (16 February 2016); the reports of the scientific consultation with Member State experts (where relevant); the comments received on the assessment of the additional information (where relevant); the comments received on the draft EFSA conclusion. Given the importance of the RAR, including its revisions (United Kingdom, 2015b), and the peer review report, both documents are considered as background documents to this conclusion and, thus, are made publicly available. It is recommended that this conclusion report and its background documents would not be accepted to support any registration outside the EU for which the applicant has not demonstrated that it has regulatory access to the information on which this conclusion report is based. 7 EFSA Journal 2016;14(3):4419

8 The active substance and the formulated product Mesotrione is the ISO common name for 2-(4-mesyl-2-nitrobenzoyl)cyclohexane-1,3-dione (IUPAC). The representative formulated product for the evaluation was Callisto 100 SC (A12739A), a suspension concentrate (SC) containing 100 g/l mesotrione. The representative use evaluated was application by spraying against annual broadleaved weeds and annual grass weeds in maize. Full details of the GAP can be found in the list of end points in Appendix A. Data were submitted to conclude that the use of mesotrione according to the representative use proposed at EU level results in a sufficient herbicidal efficacy against the target weeds following the guidance document SANCO/10054/ rev. 3 (European Commission, 2013). Conclusions of the evaluation 1. Identity, physical/chemical/technical properties and methods of analysis The following guidance documents were followed in the production of this conclusion: SANCO/3029/99-rev. 4 (European Commission, 2000a), SANCO/3030/99-rev. 4 (European Commission, 2000b), SANCO/825/00-rev. 8.1 (European Commission, 2010), SANCO/10597/2003-rev (European Commission, 2012) and SANCO/10054/2013-rev. 3 (European Commission, 2013). The reference specification for first approval was updated. The active substance is manufactured as a technical concentrate with a minimum purity of 740 g/kg. The minimum purity of the technical material on dry weight basis is 930 g/kg. No FAO specification exists. Impurities R287431, R and 1,2-dichloroethane are considered relevant impurities with maximum content of 2 mg/kg, 2 g/kg and 1 g/kg respectively (on dry weight basis) (see Section 2). The proposed specifications are based on batch data from industrial scale production and quality control data. For two of the significant impurities a data gap was set for specifying them on dry weight basis. The assessment of the data package revealed no issues that need to be included as critical areas of concern with respect to the identity, physical, chemical and technical properties of mesotrione or the representative formulation. It should however be noted that the formulation is heat sensitive. Furthermore a data gap was identified for validation data for a method used in data generation. The analytical methods used for non-radiolabelled test material used in toxicity studies have not been identified and therefore their respective validation could not be checked (data gap identified by EFSA when drafting the conclusion, see Section 2). The main data regarding the identity of mesotrione and its physical and chemical properties are given in Appendix A. Methods of analysis are available for the determination of the active substance in the technical materials and formulation and also for the determination of the relevant impurities. Mesotrione residues can be monitored in food and feed of plant origin by the QuEChERS method (LC- MS/MS) with LOQs of 0.01 mg/kg in each commodity group. Residue monitoring method for food of animal origin is not required as no MRLs were set, however mesotrione can be determined in food and feed of animal origin by the QuEChERS method (LC-MS/MS) with LOQs of 0.01 mg/kg in all animal matrices. Residues of mesotrione and its metabolites AMBA and MNBA in soil can be monitored by LC-MS/MS with LOQs of mg/kg for all three compounds. Appropriate LC-MS/MS method exists for monitoring residues of mesotrione and its metabolites AMBA and MNBA in ground water and surface water with a LOQ of 0.05 µg/l for all compounds. It should be mentioned however, that pending on the final residue definition for monitoring for the environmental compartment, additional data might be required. Residues of mesotrione in air can be monitored by LC-MS/MS with a LOQ of 0.45 µg/m EFSA Journal 2016;14(3):4419

9 The QuEChERS method (LC-MS/MS) can be used for monitoring mesotrione residues in blood with a LOQ of 0.01 mg/kg. 2. Mammalian toxicity The following guidance documents were followed in the production of this conclusion: SANCO/221/2000-rev. 10 (final) (European Commission, 2003a), SANCO/10597/2003-rev (European Commission, 2012), Guidance on the Application of the CLP Criteria (ECHA, 2015) and Guidance on dermal absorption (EFSA PPR Panel, 2012). Mesotrione was discussed at the Pesticides Peer Review Experts meeting 134 in November The technical specification is supported by the batches used in the toxicity studies. Three impurities were found to be relevant: 1,2-dichloroethane that is classified inter alia as Carc 1B (harmonised classification according to CLP Regulation 3 ), R that presented positive results in an Ames test (in the absence and presence of metabolic activation) and R that was positive in an Ames test in the absence of metabolic activation, but did not present mutagenic activity when present at 0.54% in the tested item. The toxicological relevance of the other individual impurities present in the technical specification (except the two solvents whose toxicological profile is well defined) needs to be addressed (data gap). The RMS disagreed with the setting of a data gap and in considering impurity R a relevant impurity. Bioavailability of mesotrione was found to be limited after oral administration (70% of the administered dose in rats and 50% in mice). Metabolism of the substance is limited and mesotrione is rapidly excreted (>80% within 72 hours), mostly unchanged. No potential for accumulation was observed. Low acute toxicity was observed when mesotrione was administered by the oral, dermal or inhalation routes; no skin or eye irritation and no potential for skin sensitisation were attributed to the active substance. No data have been provided to clarify the interspecies differences in metabolism; a data gap was identified for an interspecies comparative in vitro study that should include human material; the RMS disagreed with the setting of this data gap. Mesotrione is a 4-hydroxyphenylpyruvate dioxygenase (HPPD) inhibitor, a key enzyme of the tyrosine catabolic pathway, resulting in increased 4-hydroxyphenyl pyruvate, the proximal tyrosine metabolite and increased blood tyrosine concentration. This mode of action is common to herbicides of the triketone family, such as sulcotrione and tembotrione, and to the pharmaceutical drug NTBC, used in human medicine. It has been shown that the mode of action (MoA) may be relevant to all species tested but with different degree of sensitivity. Rats were recognised as being more sensitive to mesotrione and primary effects in short term and long term studies, characterized by corneal lesions, linked to tyrosinaemia, have been shown to be of lower relevance for human risk assessment. A complete toxicological dossier has been submitted on mice and this species was considered a better model in comparison to rats to extrapolate the risk to humans. However from a hazard point of view, the peer review suggested a classification of mesotrione as STOT RE 2, H373 May cause damage to organs (eyes) through prolonged or repeated exposure 4 ; the RMS disagreed with the proposed classification. Increased incidence of thyroid follicular adenomas was also considered a secondary effect of increased levels of tyrosinaemia in rats upon long term exposure and no classification proposal was retained regarding the carcinogenic potential of mesotrione. The active substance is unlikely to be genotoxic. Reproductive toxicity was investigated in rats and mice. In mice, the offspring s NOAEL was 2 mg/kg bw per day based on testes and kidney weight changes, while parental and reproductive NOAELs were 10 mg/kg bw per day based on increased tyrosinaemia and reduced successful mating respectively. Developmental toxicity was investigated in rats, mice and rabbits; in both mice and rabbit s studies, pups were found to be more sensitive than the parents (reduced/delayed ossification in the absence of maternal toxicity) and on this basis, classification as Repr. 2, H361d suspected of damaging the 3 4 Regulation (EC) No 1272/2008 of the European Parliament and of the Council of 16 December 2008 on classification, labelling and packaging of substances and mixtures, amending and repealing Directives 67/548/EEC and 1999/45/EC, and amending Regulation (EC) No 1907/2006. OJ L 353, , p It should be noted that harmonised classification and labelling is formally proposed and decided in accordance with Regulation (EC) No 1272/2008. Proposals for classification made in the context of the evaluation procedure under Regulation (EC) No 1107/2009 are not formal proposals. 9 EFSA Journal 2016;14(3):4419

10 unborn child was proposed by the peer review, in contrast with the harmonised classification according to the CLP Regulation; the RMS disagreed with the proposed classification. With regards to the assessment of endocrine disruptive properties of mesotrione, the substance is proposed to be classified as Repr. 2 for development and adverse effects were observed on endocrine organs: increased testes and epididymides weights, and thyroid adenomas in female rats. Therefore, according to the interim provisions of Annex II, point of Regulation (EC) No 1107/2009 concerning human health, mesotrione may be considered to have endocrine disrupting properties; the RMS disagreed with this statement. As no study is available to investigate a potential endocrine disrupting mode of action, a general data gap has been identified for the level 2 and 3 tests currently indicated in the OECD Conceptual Framework (OECD, 2012) and analysed in the EFSA Scientific Opinion on the hazard assessment of endocrine disruptors (EFSA Scientific Committee, 2013) to address this issue; this was identified as a critical area of concern. The RMS disagreed with the setting of a data gap and in considering the issue a critical area of concern. No neurotoxic or immunotoxic potential has been observed. Toxicological studies have been submitted on metabolites MNBA and AMBA. MNBA is of low acute toxicity by the oral and dermal routes; it is unlikely to be genotoxic and presented a lower toxicity profile compared with mesotrione. AMBA is of low acute oral toxicity and did not present mutagenic potential in an Ames test; however its genotoxic potential in vivo could not be ruled out due to positive results obtained in an in vitro cytogenetic assay, and no in vivo genotoxicity follow up testing; repeated dose toxicity would also have to be addressed as this metabolite is relevant to consumer risk assessment (see Section 3). As a groundwater metabolite, AMBA is relevant according to stage 3 of step 3 of the guidance document on the assessment of the relevance of metabolites in groundwater (European Commission, 2003a) due to its genotoxic potential and based on the classification of the parent mesotrione as Repr. 2 by the peer review. The RMS disagreed in considering the genotoxic potential of AMBA a critical area of concern. The acceptable daily intake (ADI) of mesotrione is 0.01 mg/kg body weight (bw) per day, based on decreased organ weights in pups in the mouse multigeneration study with a NOAEL of 2 mg/kg bw per day, applying an increased uncertainty factor (UF) of 200 to account for the increased tyrosinaemia at the NOAEL; this confirms the ADI set during the first evaluation of mesotrione (European Commission, 2003b). The acute reference dose (ARfD) is 0.02 mg/kg bw, based on the same NOAEL of 2 mg/kg bw per day as developmental effects may be relevant to acute exposure, standard UF of 100 applied; this confirms the ARfD set during the first evaluation of mesotrione (European Commission, 2003b). The acceptable operator exposure level (AOEL) is mg/kg bw per day based on the same NOAEL of 2 mg/kg bw per day from the mouse multigeneration study, applying a correction factor to account for the limited oral absorption in mice of 50% and an increased UF of 200 to account for the increased tyrosinaemia at the NOAEL. An AOEL of mg/kg bw per day was set during the first review of mesotrione based on the same NOAEL, an UF of 100 and corrected for limited oral absorption by 70% (European Commission, 2003b). Personal protective equipment (PPE) such as gloves during mixing, loading and application, has to be worn to ensure that the AOEL is not exceeded for operator applying the representative formulation Callisto 100SC according to the UK POEM; according to the German model, estimated operator exposure remains below the AOEL even when no PPE is considered. Estimated worker, bystander and resident s exposure does not exceed the AOEL, even when no specific PPE is considered for re-entry workers. 3. Residues The assessment in the residue section is based on the test guidelines of the Organisation for Economic Co-operation and Development Nos. 501 to 509 (OECD, 2007a-g, 2008, 2009a,b), the Joint Meeting on Pesticide Residues (JMPR) recommendations on livestock burden calculations (JMPR, 2004, 2007), the OECD publication on MRL calculations (OECD, 2011) and the European Commission guideline document on data requirements for setting MRLs (European Commission, 2015). Mesotrione was discussed at the Pesticides Peer Review Meeting 135 in December Plant metabolism was studied in maize (pre- and post-emergence), peanuts (pre-emergence) and genetically modified soya bean (pre-, post-emergence and combined pre-/post-emergence) with 10 EFSA Journal 2016;14(3):4419

11 mesotrione labelled on cyclohexane-2-14 C and phenyl-u- 14 C. The metabolic pattern of mesotrione was found to be quantitatively different in conventional crops (maize, peanut) compared to genetically modified soya bean. In maize and peanuts, parent mesotrione was hardly recovered (3% TRR in maize forage only) whilst the most pertinent metabolites identified in the feed items were MNBA (up to 20% TRR in maize forage leaves) and AMBA, free and conjugated (13% and 28% TRR respectively in maize forage leaves and fodder; 15% TRR in peanut meat). Further metabolites identification was not conducted in maize grain due to the very low recovered total residues (0.014 mg/kg). In genetically modified herbicide tolerant soya bean, parent mesotrione was less extensively metabolised compared to conventional crops and occurred in forage at up to 18% TRR and in soya bean seed (10% TRR). The predominant compounds were identified as 4/5-hydroxy mesotrione (forage 19% TRR; hay 25% TRR; seed 8% TRR) and MNBA (forage 25% TRR; hay 20% TRR; seed 5% TRR). AMBA compound was never detected. The unextracted radioactivity was further characterized as polar compounds (soya bean), lipids (peanut meat) and carbohydrates (maize) incorporated into the natural constituents of the plant. The metabolism of mesotrione in maize, peanuts and soya bean proceeds by oxidation of the parent molecule to 4/5-hydroxy mesotrione and to MNBA with subsequent reduction to AMBA and its conjugates observed in conventional maize and peanuts only. The metabolism of mesotrione in rotational crops was found to be similar to the primary crops. Since the absolute concentration of all metabolites was below 0.01 mg/kg in the seeds, the residue definition for enforcement and risk assessment was set as mesotrione only for food commodities. For feed commodities, the potential inclusion of the predominant metabolites MNBA and AMBA (free and conjugated) besides mesotrione in the residue definition for risk assessment was envisaged. MNBA was characterized as non genotoxic and of lower toxicity compared to the parent compound and was never detected in the GAP-compliant residue trials on maize (<0.01 mg/kg). In contrast, a genotoxic potential in vivo could not be excluded for AMBA and repeated dose toxicity profile needs to be addressed (see data gap in section 2). For risk assessment in feed commodities and pending on the toxicological profile of AMBA conjugates, the residue definition is provisionally proposed as mesotrione and AMBA (including its conjugates). If it can be demonstrated that the conjugates of AMBA are not genotoxic and of no toxicological relevance, additional residue trials on maize where AMBA is analysed for are not needed and only mesotrione has to be included in the residue definition. These residue definitions are valid for conventional crops (cereals, pulses and oilseeds) only. For future uses on genetically modified crops and considering the significant proportions of 4/5-hydroxy mesotrione recovered in soya bean forage and hay, this compound may have to be included in the residue definition for risk assessment pending on its toxicological relevance. Sufficient GAP-compliant residue trials supported by acceptable storage stability data are available to derive a MRL for mesotrione on maize grain. Hydrolysis studies addressing the nature of the residues in processed commodities are not triggered. The livestock dietary burden was tentatively estimated using the highest magnitude of AMBA conjugates residues in maize forage, fodder from the metabolism study and the total residues in maize grain. In this case, livestock metabolism studies are not triggered. A ruminant metabolism study was however conducted with phenyl-u- 14 C AMBA. The total residues were below 0.01 mg/kg in all matrices except in kidney (0.053 mg/kg) and fat (0.018 mg/kg) with AMBA being the predominant compound that accounted for 79% TRR and 62% TRR, respectively. At the estimated dietary burden, the transfer of AMBA residues in all matrices was shown to be negligible and residue definitions for animal commodities are provisionally not required for the representative use. This assessment has however to be reconsidered pending the outcome of AMBA toxicity (see Section 2). Furthermore, the setting of residue definitions for products of animal origin will also have to be assessed with regard to the authorized European uses for mesotrione (maize forage, grass) (EFSA, 2015), and in the case animals are fed with genetically modified soya bean seed (meal) where mesotrione can be find at significant proportions. The consumer risk assessment was performed with the EFSA PRIMo rev.2a. No chronic and acute intake concerns were identified (TMDI: 0.2% of ADI (WHO Cluster diet B); IESTI: 0.3% of ARfD) considering the MRL on maize grain only. The consumer dietary risk assessment could however not be finalised with regard to products of animal origin as the genotoxic potential of AMBA in vivo could not be ruled out due to positive results obtained in an in vitro cytogenetic assay EFSA Journal 2016;14(3):4419

12 A data gap was also identified for the determination of the residues in pollen and bee products for human consumption. It is noted that RMS disagreed with the setting of this data gap. 4. Environmental fate and behaviour Mesotrione was discussed at the Pesticides Peer Review Meeting TC 124 in November The route and rate of degradation of mesotrione ( 14 C labelled at the cyclohexane and or phenyl rings) in soil under dark aerobic conditions at 20ºC was investigated in 18 soils. The rates of dissipation and degradation in the environmental matrices investigated were estimated using FOCUS (2006) kinetics guidance. Mesotrione exhibited low to moderate persistence in these experiments. A ph dependence of the rate of degradation could be assumed from the available data. Peer review agreed to use a fitting of data to a lineal relationship to represent this dependence in environmental modelling. Mesotrione degraded to form metabolites MNBA (max. 57.2% AR after 28 d) and AMBA (max. 9.3% AR after 13 days). MNBA exhibited very low to moderate persistence and AMBA low to moderate persistence. Unextractable radioactivity increased up to 37. 6% AR (after 28 d) and volatiles trapped in the alkaline trap (assumed to be CO 2 ) increased up to 37.6% AR (after 121 d) in the phenyl radiolabeled mesotrione experiments. Unextractable radioactivity increased up to 15.2% AR (after 21 d) and volatiles trapped in the alkaline trap (assumed to be CO 2 ) increased up to 75.2% AR (after 58 d) in the cyclohexane radiolabeled mesotrione experiments. Mesotrione degradation in soil under anaerobic conditions was investigated in one study. Mesotrione was low persistent under these conditions. Metabolite AMBA reached 40.7% AR after 30 d. Photolysis of mesotrione in soil was investigated in a study submitted for the renewal application in a microbially active soil under dry and wet conditions irradiated by simulated sunlight. Photolysis can enhance degradation of mesotrione (especially when dry conditions prevail and lower microbial competition occurs). Field dissipation studies carried out at four sites in Germany, two in Italy and one in France are available. However, results from these studies have not been relied on for the assessment performed in the context of the renewal of the authorisation. PEC soils were calculated for parent mesotrione and the metabolites MNBA and AMBA for the representative use in maize based on standard calculation and worst case assumptions. Batch soil adsorption/desorption studies were performed with mesotrione in 10 soils and with metabolites MNBA and AMBA with two and three soils respectively. In addition, a batch soil adsorption/desorption study has been performed with metabolite SYN identified in the watersediment study. According to these studies mesotrione may be considered to exhibit very high to medium mobility in soil. A ph dependence could be assumed from the available data. Peer review agreed to use a fitting of data to an exponential curve to represent this dependence in environmental modelling. Metabolite MNBA may be considered to exhibit very high mobility and metabolite AMBA high to very high mobility. Water / sediment metabolite SYN may be considered to be low mobile to immobile in soil (K Foc = ml / g). Neither column leaching nor lysimeter studies were provided in the dossier presented for the renewal authorisation of mesotrione. Hydrolysis of mesotrione in water was investigated in buffered solutions (ph 4, 5, 7 and 9) at temperatures in the range of 25 50ºC. Mesotrione was stable in the whole range of ph investigated. Direct and indirect aqueous photolysis of mesotrione was investigated in two separated studies simulating sunlight radiation. In the lack of a study investigating biodegradability of mesotrione, it is assumed to be not readily biodegradable. Fate and behaviour of mesotrione in dark water sediment systems under aerobic conditions was investigated in four systems (two of them were investigated using mesotrione labelled in cyclohexane and phenyl rings). Mesotrione partitioned to the sediment in a very low extend (max 4.3% AR after 1 d) and most of the product remained in the water phase. Degradation was relatively fast in all systems tested (DT 50 whole system = days). Even after normalising to 12ºC persistence triggers were not exceeded for fresh water compartment (ECHA, 2014). Three metabolites were found in the in water phase: MNBA (max. 7.4% AR after 3 days), AMBA (max. 15.8% AR after 46 days) and 12 EFSA Journal 2016;14(3):4419

13 SYN (max. 9.4% AR after 29 d). Metabolites AMBA and SYN were found in the sediment at significant amounts (AMBA max. 8.8% AR after 46 d; SYN max. 25.6% AR after 102 d). Mineralization was generally low (lower for the phenyl ring labelled substance than the cyclohexane labelled one) and the un-extractable residue in the sediment increased up to 73.7% AR at end of the study. PEC sw were calculated for parent mesotrione and metabolites MNBA, AMBA and SYN with FOCUS SW tools up to step 2. FOCUS sw Step 3 and Step 4 concentrations assuming mitigation up to 20 m by spray drift buffers and vegetative run off strips were also calculated for parent mesotrione in order to characterize feasibility of mitigation considered in the assessment of potential unacceptable effects to the aquatic environment. The ph dependence observed on the degradation and soil adsorption of mesotrione was taken into account in these calculations (FOCUS, 2001; FOCUS, 2007). However, risk managers and others may wish to note that whilst run-off mitigation is included in the step 4 calculations available, the FOCUS (FOCUS, 2007) report acknowledges that for substances with K Foc < 2000 ml/g (i.e. mesotrione), the general applicability and effectiveness of run-off mitigation measures had been less clearly demonstrated in the available scientific literature, than for more strongly adsorbed compounds. Potential for ground water contamination by mesotrione and soil metabolites MNBA and AMBA was assessed by calculation of 80 th percentile of 20 years annual average concentrations at 1m depth with FOCUS sw PEARL v and PELMO v models for the representative use in maize, selecting input values based on ad hoc estimation of most relevant soil phs for maize in EU (using GIS assessment). Limit of 0.1 μg/l was only exceeded by metabolite MNBA in one of the eight relevant FOCUS gw scenarios (Hamburg) when a soil ph of 5.1 was assumed (FOCUS, 2009; European Commission, 2003a). At national and zonal level, or for crops other than maize, MSs may need to reassess the choice of ph for which groundwater and surface water exposure is calculated to ensure representativeness based on GIS assessments. The applicant provided a statement to address the effect of water treatments processes on the nature of the residues that might be present in surface water and groundwater, when surface water or groundwater are abstracted for drinking water. According to this statement the formation of potential harmful transformation products cannot be ruled out. Therefore a data gap has been identified to address the substances of potential toxicological concern that could be derived from mesotrione and its metabolites under water treatment procedure conditions. Those substances indicated in the applicants statement (concerning any potential formation of nitrosobenzene, nitrobenzene (MNBA) or azobenzene analogues) and those identified by Member States experts during the peer review (nitrosamine production from AMBA metabolite) would need to be addressed. A study to investigate if these compounds are actually formed and in which proportion needs to be provided to assess if the approval criteria in Article 4 of Regulation (EC) No 1107/2009 are satisfied. 5. Ecotoxicology The risk assessment was based on the following documents: European Commission (2002a, b), SETAC (2001) and EFSA (2009), EFSA PPR Panel (2013) and EFSA (2013). According to Regulation (EU) No 283/2013 data should be provided regarding the acute and chronic toxicity to honeybees and data to address the development of honeybee brood and larvae. As the European Commission (2002a) does not provide a risk assessment scheme which is able to use the chronic toxicity data for adult honeybees and the honeybee brood, when performing the risk assessment according to European Commission (2002a), the risk to adult honeybees from chronic toxicity and the risk to bee brood, could not be finalised due to the lack of a risk assessment scheme. Therefore, the EFSA (2013) was used for risk assessment in order to reach a conclusion for the representative uses. Mesotrione was discussed at the Pesticides Peer Review experts Meeting 136 in December Specifically two issues were examined: 1) the relevant endpoint to be used in the reproductive risk assessment for mammals; 2) the approaches proposed for the probabilistic risk assessment for nontarget terrestrial plants. For birds a low acute risk via dietary exposure was concluded at the screening step for the representative uses on maize. A low long-term risk was concluded at tier 1 for all the generic focal 13 EFSA Journal 2016;14(3):4419

14 species via dietary exposure for the representative use. The risk from consumption of contaminated water was assessed as low. For wild mammals a low acute risk via dietary exposure was concluded at the screening level for the representative use on maize. The long-term endpoint for mammals was discussed at the Pesticides Peer Review experts Meeting 136 in December The experts agreed on a NOAEL of 0.3 mg/kg bw per day based on the effects on litter size of the F2 generation. The long-term risk to mammals was assessed as high for all scenarios at the tier 1. For risk refinement, a range of studies were available for identification of specific focal species and PT values. The omnivorous wood mouse (Apodemus sylvaticus) and the herbivorous European brown hare (Lepus europaeus) were considered appropriate focal species for maize at the early stages after germination (BBCH 10-16). Based on the provided dataset, the PT refinement was possible only for the wood mouse. It was not possible to further refine the risk assessment based on residue decline data, as no reliable DT 50 on maize could be derived. Overall, the long-term risk to mammals was concluded as high. Therefore, a data gap was identified. No secondary poisoning assessment was triggered for mesotrione and its metabolites (LogKow<3). The long-term risk to mammals via consumption of contaminated water was assessed as high at tier 1 level. Therefore a data gap was identified. A high long-term risk to aquatic macrophytes from the exposure to mesotrione was identified for 6 out of 8 FOCUS scenarios at Step 3, while a low risk for all the other aquatic organisms was concluded at the FOCUS sw step 1. A high risk for aquatic macrophytes was still identified in three scenarios (R2, R3, and R4) considering PECsw calculated at FOCUS Step 4 where a 20 m vegetated buffer strip as mitigation measure was considered. Therefore a data gap was identified to further refine the risk to aquatic organisms in these scenarios. A low risk was concluded for all other scenarios provided that in three of them (D3, D6, and R1) mitigation measures equivalent to 5 m no-spray buffer zone (D3 and D6) or a 20 m no-spray buffer zone and 20 m vegetated buffer strip (R1) are put in place. The risk to aquatic organisms for the metabolites MNBA, AMBA and SYN was assessed as low at FOCUS sw Step 1 for the representative use on maize. Additionally, the risk to aquatic organisms to the metabolites MNBA and AMBA via groundwater contamination was assessed as low according to the representative use on maize. Acute contact and acute oral toxicity studies for honeybees, performed with the active substance and the representative formulation were available. A honeybee chronic oral toxicity study with the formulation was available. A semi-chronic laboratory study on larvae with the formulation was also available. An assessment of the hypopharyngeal glands (HPG) was not performed; therefore a data gap was identified. A low acute contact and oral risk was concluded on the basis of a screening level assessment. The first tier chronic assessment via oral exposure indicated a low risk to honeybees for all the scenarios for the representative use on maize. A risk could not be excluded at the screening level for adult honeybees and for larvae from the exposure via residues in guttation fluid for the representative use on maize. Therefore, further risk assessment refinements would be needed for this route of exposure (data gap). A low risk for adult honeybee and larvae was concluded from the exposure via residues in the surface water on the basis of PEC sw FOCUS step 1. No specific assessment was performed for puddle scenario. Therefore, a data gap was identified. Insufficient information was available to perform a risk assessment to honeybees for relevant metabolites in pollen and nectar. Therefore, a further data gap was identified. Addressing this data requirement, it is suggested that EFSA (2013) is used for identification of those metabolites requiring assessment. No assessment for accumulative effects was available. No data were available to perform a risk assessment for bumble bees or solitary bees EFSA Journal 2016;14(3):4419

15 For non-target arthropod species other than bees a low off-field risk was concluded for both Typhlodromus pyri and Aphidius rhopalosiphi at tier 1, whereas the in-field risk was only assessed as low for Typhlodromus pyri for the representative field use on maize. The in-field risk for Aphidius rhopalosiphi was assessed as low based on extended laboratory tests. A low acute and long-term risk was identified for earthworms, other non-target soil macro fauna and for nitrogen transformation for the representative use on maize. For terrestrial non-target plants, studies were available to investigate the effects on vegetative vigour and seedling emergence. Moreover, three semi-field studies were submitted, investigating four different plant species (i.e., Brassica rapa, Cucumis sativa, Lactuca sativa and Lycopersicon esculentum) at early, middle and late growth stages. The probabilistic approach to be used was discussed at the Pesticides Peer Review Experts Meeting 136 in December The experts agreed on a probabilistic risk assessment for non-target terrestrial plants, where the most sensitive endpoint for each species (i.e. monocotyledons and dicotyledons) from the vegetative vigour study, including a single unbounded value, was used. As a consequence a low risk was concluded with mitigation measures equivalent to in-field no-spray buffer zones of 20 m and 50% drift reducing nozzles. A data gap was identified to further address the sensitivity to mesotrione of dicotyledonous plant species and monocotyledonous plant species. A low risk was also concluded for the representative uses of mesotrione for organisms involved in biological methods for sewage water treatment. A non-identified metabolite (metabolite A) (max 9.7% AR) exceeded levels above 5% AR from day 5 to day 30 (end of the study). A data gap has been identified in Section 4 for further consideration of this metabolite in case anaerobic conditions cannot be excluded. No assessment on the endocrine disrupting potential was carried out for birds and fish species. However, reference is made to the mammalian toxicology section, where the active substance is proposed to be classified as Repr. Cat. 2 and adverse effects were observed on endocrine organs EFSA Journal 2016;14(3):4419

16 6. Overview of the risk assessment of compounds listed in residue definitions triggering assessment of effects data for the environmental compartments Table 1: Soil Compound Persistence Ecotoxicology (name and/or code) mesotrione low to moderate (DT 50 = 4.3 d 28.7 d) Low risk to soil-dwelling organisms MNBA very low to moderate (DT 50 = 0.5 d 15.7 d) Low risk to soil-dwelling organisms AMBA low to moderate (DT 50 = 7.8 d 58.7 d) Low risk to soil-dwelling organisms Table 2: Groundwater Compound (name and/or code) mesotrione MNBA AMBA Mobility in soil very high to medium (K Foc = ml/g). A ph dependence was identified. very high (K Foc = ml/g) high to very high mobility (K Foc = ml/g) > 0.1 μg/l at 1 m depth for the representative uses (at least one FOCUS scenario or relevant lysimeter) Pesticidal activity Toxicological relevance Ecotoxicology FOCUS GW: No Yes Yes A high risk for aquatic organisms was indicated in the surface water risk assessment. FOCUS GW: No No Yes, based on the proposed classification by the peer review as Repr MNBA is unlikely to be genotoxic and present a lower toxicity profile than the parent mesotrione FOCUS GW: No No Yes, based on the proposed classification by the peer review as Repr Genotoxic potential cannot be ruled out due to positive effects observed in an in vitro clastogenicity assay A low risk was indicated for aquatic organism from exposure via groundwater contamination A low risk was indicated for aquatic organism from exposure via groundwater contamination 5 Not in agreement with harmonised classification Annex VI of Regulation (EC) No 1272/2008 (CLP Regulation) 16 EFSA Journal 2016;14(3):4419