Conclusion on the peer review of the pesticide risk assessment of the active substance dicamba 1

Transcription

1 CONCLUSION ON PESTICIDE PEER REVIEW Conclusion on the peer review of the pesticide risk assessment of the active substance dicamba 1 SUMMARY European Food Safety Authority 2 European Food Safety Authority (EFSA), Parma, Italy Dicamba is one of the 84 substances of the third stage part B of the review programme covered by Commission Regulation (EC) No 1490/2002 3, as amended by Commission Regulation (EC) No 1095/ Dicamba was included in Annex I to Directive 91/414/EEC on 1 January 2009 pursuant to Article 11b of the Regulation (EC) No 1490/2002, as amended by Commission Regulation (EC) No 1095/2007 (hereinafter referred to as the Regulation ). In accordance with Article 12a of the Regulation the European Food Safety Authority (EFSA) is required to deliver by 31 December 2010 its view on the draft review report submitted by the Commission of the European Communities (hereinafter referred to as the Commission ) in accordance with Article 12(1) of the Regulation. This review report was established as a result of the initial evaluation provided by the designated rapporteur Member State in the Draft Assessment Report (DAR). The EFSA therefore organised a peer review of the DAR. The conclusions of the peer review are set out in this report. Denmark being the designated rapporteur Member State submitted the DAR on dicamba in accordance with the provisions of Article 10(1) of the Regulation, which was received by the EFSA on 13 March The peer review was initiated on 7 November 2007 by dispatching the DAR to the notifier Syngenta Crop Protection AG, and on 10 March 2009 to the Member States for consultation and comments. Following consideration of the comments received on the DAR, it was concluded that EFSA should conduct a focused peer review in the areas of mammalian toxicology, residues, environmental fate and behaviour and ecotoxicology, and deliver its conclusions on dicamba. The conclusions laid down in this report were reached on the basis of the evaluation of the representative uses of dicamba as a herbicide on maize and pasture, as proposed by the notifier. Full details of the representative uses can be found in Appendix A to this report. No critical areas of concern are identified in the physical-chemical area. Data gaps are identified for the methods of analysis in products of plant and animal origin, and in air. No critical areas of concern or data gaps are identified in the mammalian toxicology section. Based on the plant metabolism studies performed on the cereal and pulse/oilseed plant groups, the residue was defined as dicamba and its salts (free and conjugates) for monitoring and as dicamba and 1 On request from the European Commission, Question No EFSA-Q , issued on 17 December Correspondence: praper@efsa.europa.eu 3 OJ L 224, , p.25 4 OJ L 246, , p.19 Suggested citation: European Food Safety Authority; Conclusion on the peer review of the pesticide risk assessment of the active substance dicamba.. [52 pp.] doi: /j.efsa Available online: European Food Safety Authority, 2011

2 5-OH-dicamba (free and conjugated) for risk assessment. For ruminants, the residue definition for monitoring and risk assessment was limited to the parent compound only (free and conjugated). No concerns for the consumer were identified in the residue section. Further information is required to confirm to confirm that the analytical methods used to generate the data on grass are able to release the conjugates. The data available on fate and behaviour in the environment are essentially sufficient to carry out the required environmental exposure assessments at EU level for the representative uses. However, the detailed quantification/identification of a group of unidentified transformation products, found in one soil incubation, was not available. Therefore there are no assessments for the environmental compartments for any potentially formed soil transformation products from this group that would trigger further evaluations. The potential for groundwater exposure by dicamba or its identified major soil metabolite is predicted to be low over a wide range of geoclimatic conditions represented by the FOCUS groundwater scenarios. Dicamba has the potential for long-range transport through the atmosphere. This issue was therefore identified as a critical area of concern. No data gaps or critical areas of concern are identified in the ecotoxicology section. Risk mitigation comparable to an in-field no-spray buffer zone of 5 m was required to protect non-target plants in the off-field area. KEY WORDS Dicamba, peer review, risk assessment, pesticide, herbicide 2

3 TABLE OF CONTENTS Summary... 1 Table of contents... 3 Background... 4 The active substance and the formulated product... 6 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 Soil Ground water Surface water and sediment Air List of studies to be generated, still ongoing or available but not peer reviewed Particular conditions proposed to be taken into account to manage the risk(s) identified Issues that could not be finalised Critical areas of concern References Appendices Abbreviations

4 BACKGROUND Dicamba is one of the 84 substances of the third stage part B of the review programme covered by Commission Regulation (EC) No 1490/2002 5, as amended by Commission Regulation (EC) No 1095/ Dicamba was included in Annex I to Directive 91/414/EEC on 1 January 2009 pursuant to Article 11b of the Regulation (EC) No 1490/2002, as amended by Commission Regulation (EC) No 1095/2007 (hereinafter referred to as the Regulation ). In accordance with Article 12a of the Regulation the European Food Safety Authority (EFSA) is required to deliver by 31 December 2010 its view on the draft review report submitted by the Commission of the European Communities (hereinafter referred to as the Commission ) in accordance with Article 12(1) of the Regulation (European Commission, 2008). This review report was established as a result of the initial evaluation provided by the designated rapporteur Member State in the Draft Assessment Report (DAR). The EFSA therefore organised a peer review of the DAR. The conclusions of the peer review are set out in this report. Denmark being the designated rapporteur Member State submitted the DAR on dicamba in accordance with the provisions of Article 10(1) of the Regulation, which was received by the EFSA on 13 March 2007 (Denmark, 2007). The peer review was initiated on 7 November 2007 by dispatching the DAR to the notifier Syngenta Crop Protection AG, and on 10 March 2009 to the Member States for consultation and comments. In addition, the EFSA conducted a public consultation on the DAR. The comments received were collated by the EFSA and forwarded to the RMS for compilation and evaluation in the format of a Reporting Table. The comments were evaluated by the RMS in column 3 of the Reporting Table. The Reporting Table containing the RMS evaluation of the comments in column 3 was further considered by the EFSA, resulting in a conclusion in column 4. All points that were identified as unresolved at the end of the comment evaluation phase, and which required further consideration in the peer review process, were compiled by the EFSA in the format of an Evaluation Table. The notifier was invited to respond to the issues identified in the Evaluation Table in column B. The notifier s response was evaluated by the RMS in column C. The scope of the peer review was considered in a telephone conference between the EFSA, the RMS, and the Commission on 27 August On the basis of the comments received, the further information made available by the notifier in column B of the Evaluation Table and the RMS evaluation thereof it was concluded that the EFSA should organise a consultation with Member State experts in the areas of mammalian toxicology, residues, environmental fate and behaviour and ecotoxicology. The outcome of the telephone conference, together with the conclusions arising from the consideration by the EFSA, and as appropriate by the RMS, of the points identified in the Evaluation Table, as well as the outcome of the expert discussions where these took place, was 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 November December This conclusion report summarises the outcome of the peer review of the risk assessment on the active substance and the representative formulation evaluated on the basis of the representative uses as a herbicide on maize and pasture, as proposed by the notifier. A list of the relevant end points for the active substance as well as the formulation is provided in Appendix A. In addition, a key supporting document to this conclusion is the Peer Review Report, 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 (EFSA, 2010) comprises the following documents: 5 OJ L 224, , p.25 6 OJ L 246, , p. 19 4

5 the comments received on the DAR, the Reporting Table (revision 1-1; 31 July 2009), the Evaluation Table (17 December 2010), the report(s) of the scientific consultation with Member State experts (where relevant). Given the importance of the DAR including its addendum (compiled version of November 2010 containing all individually submitted addenda (Denmark, 2010)) and the Peer Review Report, both documents are considered respectively as background documents A and B to this conclusion. 5

6 THE ACTIVE SUBSTANCE AND THE FORMULATED PRODUCT Dicamba is the ISO common name for 3,6-dichloro-2-methoxybenzoic acid (IUPAC). The representative formulated product for the evaluation was Banvel 480 SL, a soluble concentrate (SL), containing 480 g/l dicamba. The representative uses evaluated comprise outdoor foliar spraying against dicotyledon weeds in maize and pasture. Full details of the representative uses can be found in the list of end points in Appendix A. 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/3030/99 rev.4 (European Commission, 2000), Sanco/10597/2003 rev. 8.1 (European Commission, 2009), and SANCO/825/00 rev. 7 (European Commission, 2004a). The minimum purity of dicamba as manufactured is 850 g/kg; this is in line with the FAO specification, which is applicable to this Syngenta source as well as sources from BASF and Gharda. The technical material contains no relevant impurities. The main data regarding the identity of dicamba and its physical and chemical properties are given in Appendix A. A GC-MS method is available for plants that claims to analyse both free and conjugated dicamba, however the hydrolysis step is not validated, therefore a data gap has been identified. A method of analysis for animal products is not available and a data gap is identified as MRLs are proposed. For soil a GC-MS method is available to analyse for dicamba and DCSA. In water GC-MS methods are available for dicamba, DCSA and 5-OH-dicamba. It should be noted however, that as the methods for plants and soil contain a hydrolysis step they are not specific for dicamba and its salts as they will also hydrolyse esters if dicamba had been applied in an ester form. The air method is not fully validated, therefore a data gap has been identified. A method of analysis for body fluids and tissues is not required as the active substance is not classified as toxic or very toxic. 2. Mammalian toxicity The following guidance documents were followed in the production of this conclusion: SANCO/221/2000 rev. 10 (European Commission, 2003), SANCO/22/200 rev. 7 (European Commission, 2004b). Dicamba was discussed at the PRAPeR 83 Experts Meeting on mammalian toxicology. The technical specification is supported by the batches used in the toxicological studies. The impurities are not considered relevant from the toxicological point of view. Oral absorption was estimated to be higher than 80 %. It is widely distributed. There was no evidence for accumulation and very limited metabolism was observed. Low acute toxicity is observed when dicamba is administered by the dermal route. It is harmful if swallowed and by inhalation, and it is a severe eye irritant. Slight skin irritation was observed and there was no potential for skin sensitisation. In short-term oral studies with dogs and rats, the critical effects were observed in the liver (rats) and haematology parameters (rats and dogs). Non-specific critical effects such as reduced body weight gain were also observed in rats and dogs. The dog was the most sensitive species. The relevant shortterm oral NOAEL is 50 mg/kg bw/day (90-day dog study). No potential for genotoxicity is attributed to dicamba in well conducted and GLP-compliant genotoxicity studies. 6

7 In long-term studies with mice and rats, the maximum tolerable dose (MTD) was not reached. The only adverse effect observed in mice was the slightly reduced body weight gain at 364 mg/kg bw/day, with the NOAEL being 121 mg/kg bw/day. In rats, no adverse effects were observed up to the dose level of 120 mg/kg bw/day. Although the MTD was not reached, the studies were considered appropriate for risk assessment purposes. No carcinogenic potential is attributed to dicamba. Fertility and overall reproductive performance was not impaired. The parental NOAEL is 105 mg/kg bw/day, the offspring NOAEL is 35 mg/kg bw/day, and the reproductive NOAEL is set at 350 mg/kg bw/day. In the developmental toxicity studies, there was no evidence of teratogenicity, and the relevant maternal NOAELs are 160 mg/kg bw/day for rats and 30 mg/kg bw/day for rabbits; the developmental NOAELs are 400 and 150 mg/kg bw/day, respectively for rats and rabbits. No direct potential for neurotoxicity, including delayed neurotoxicity, was observed in neurotoxicity studies. Toxicological studies provided for the metabolite 5-OH-dicamba indicate that this metabolite is not of higher toxicity than the parent compound, and therefore the reference values of dicamba can also be applicable to this metabolite. With regard to the metabolite DCSA, the available toxicological information was limited but sufficient to support an ADI of 0.01 mg/kg bw/day. The acceptable daily intake (ADI) is 0.3 mg/kg bw/day, based on the offspring NOAEL of 35 mg/kg bw/day found in the multigeneration study and applying a safety factor of 100. The acceptable operator exposure level (AOEL) is 0.3 mg/kg bw/day, based on the rabbit maternal NOAEL of 30 mg/kg bw/day and applying a safety factor of 100. No correction for oral absorption is needed to derive the AOEL. The acute reference dose (ARfD) is 0.3 mg/kg bw, based on the rabbit maternal NOAEL of 30 mg/kg bw/day and applying a safety factor of 100. Considering the representative uses on maize and pasture the estimated operator exposure is below the AOEL, even without the use of personal protective equipment (PPE). Worker and bystander exposure estimates are also below the AOEL. 3. Residues The assessment in the residue section below is based on the guidance documents listed in the document 1607/VI/97 rev.2 (European Commission, 1999), and the JMPR recommendations on livestock burden calculations stated in the 2004 and 2007 JMPR reports. Metabolism in plants was investigated in cereals (wheat, sugar cane) and in the pulse/oilseed plant group (soya, cotton), using 14 C-dicamba labelled on the phenyl moiety applied by foliar spraying (wheat), or by droplet applications by means of a micro-syringe to a limited number of leaves (sugar cane, soya, cotton). In sugar cane, soya and cotton, where the characterization of the residues was investigated shortly after the application (6 to 28 days), dicamba remains the major component of the residues, accounting for % of the TRR in sugar cane leaves, % of the TRR in soya beans, and 72 % of the TRR in cotton seed. Other identified metabolites were observed in low proportions (< 2 % TRR), except 5-OH-dicamba, which represented 47 % and 20 % of the TRR in sugar cane leaves, 12 and 28 days after application, respectively. In wheat, dicamba seems to be more extensively metabolised, accounting for 10 % of the TRR in immature plant (forage), and 2 % and 16 % of the TRR respectively in straw and grain at harvest. 5-OH-dicamba is detected as the major metabolite in wheat forage (65 % TRR), but it represents less than 4 % TRR in grain and straw at harvest. Both the parent compound and 5-OH-dicamba were observed in free and conjugated form. Considering the different structures identified, the following metabolic pathway in plants was proposed. The metabolism of dicamba proceeds first by hydroxylation to form 5-OH-dicamba, or by demethylation to the DCSA metabolite, both compounds being further degraded to DCGA. Based on these studies, it was proposed to define the residue for monitoring as dicamba and its salts (free and conjugates). For risk assessment, the PRAPeR TC 50 discussed whether 5-OH-dicamba should be included additionally in the residue definition, since it was not observed at significant levels in the 7

8 edible parts used for human consumption. Finally, and considering the conclusion of the PRAPeR meeting on mammalian toxicology (PRAPeR 83) stating that 5-OH-dicamba is not of higher toxicity than the parent compound, and having regard to the important levels at which this metabolite was observed in the residue trials conducted on pasture, it was agreed to include this metabolite in the residue definition for risk assessment. Supervised residue trials on maize and pasture, conducted in northern and southern EU were provided. The samples were analysed for dicamba and 5-OH-dicamba, using an analytical method including a hydrolysis step in order to take into account the conjugates. However, additional information is required to confirm that the analytical methods used to generate the data on grass are able to release the conjugates, therefore a data gap has been identified. In pasture, some trials were conducted with a single application only, but they were considered appropriate as the residue levels were found to be similar to those observed in the trials performed according to the GAP, with a total of 2 applications. Moreover, the contribution of the first treatment to the final level was shown to be limited, since low levels were detected in the samples collected just before the second application. Significant residues were observed in grass, up to 13.8 mg/kg and 7.9 mg/kg for dicamba and 5-OH-dicamba respectively, with the 5-OH-dicamba levels at PHI 14 days being approximately 50 % of the dicamba levels. Contrary to grass, no residues were detected in maize grains, with all values being below the LOQ of 0.01 mg/kg for both compounds. These residue data are supported by the storage stability study showing dicamba and 5-OH-dicamba residues to be stable for up to 36 months in maize matrices (forage, fodder and grain), when stored frozen at c.a. -17 C. Processing studies were not provided and are not required as residues in maize grains were below the LOQ. Metabolism in animals was considered in cow, goat and poultry, using 14 C-dicamba. The transfer in fat, milk and eggs was limited, the highest TRRs being observed in kidney and liver. Dicamba (free and conjugated) was by far the major compound identified in all animal matrices, accounting for more than 50 % of the TRR. In addition, DCSA was also observed in ruminants, but only in kidney and liver, up to 21 % of the TRR. 5-OH-dicamba was not detected in animal matrices, except in urine and excreta, but at insignificant levels and proportions (< 0.01 % TRR). Having regard to the high levels of 5-OH-dicamba in grass, and consequently its significant intake by ruminants (c.a. 1.5 mg/kg bw/day), the PRAPeR TC 50 meeting of experts discussed whether a specific metabolism study using this metabolite needs to be required. The experts were of the opinion that a similar pathway to the parent is expected for 5-OH-dicamba, this metabolite being probably more extensively excreted than the parent compound since it is more polar. This assertion is supported by the results of the cow feeding study conducted with 5-OH-dicamba, where this metabolite was almost not detected in any matrices, except in kidney, at the 5N dose rate. It was therefore concluded that a specific ruminant metabolism study should not be required for 5-OH-dicamba. Finally, dicamba and its salts (free and conjugates) was proposed to define the residue for monitoring, and MRLs were derived for ruminant products from the feeding study conducted with the parent dicamba. For risk assessment, considering the lower ADI of 0.01 mg/kg bw/day proposed for the metabolite DCSA when compared to the parent compound (see section 2), the PRAPeR TC 50 meeting of experts proposed to define the residue as parent dicamba and DCSA (free and conjugates). However, after the meeting, the consumer risk assessment conducted for DCSA, taking into account the expected residue levels in kidney and liver, showed highest intakes below 0.2 % of the ADI. Having regard to the very low contribution of the DCSA metabolite to the consumer exposure and considering that the animal intake will not be increased if additional uses are envisaged, EFSA is of the opinion that the residue definition for risk assessment should be limited to the parent dicamba only. No concern for the consumers was identified, the highest TMDI being less than 1% of the ADI for all the diets included in the EFSA PRIMo model, and the highest IESTI only 2 % of the ARfD (milk). 4. Environmental fate and behaviour In soil laboratory incubations under aerobic conditions in the dark, dicamba exhibits low persistence, forming only one major (> 10 % applied radioactivity (AR)) soil metabolite, DCSA. However, a data gap was identified for the detailed quantification/identification of a group of unidentified 8

9 transformation products found in a soil incubation study to clarify whether this group contains any metabolite that would trigger further evaluations. The rate of mineralization to carbon dioxide varied between % AR after days. The formation of unextractable residues was a sink, accounting for % AR after 120 days. The degradation in soil under anaerobic conditions was not investigated, and no significant degradation was observed in the study on photolysis in soil. The metabolite DCSA exhibited low to moderate persistence in laboratory soil experiments. Dicamba exhibits very high mobility, while the metabolite DCSA exhibits medium to slight mobility in soil. Dicamba is considered moderately persistent (DT 50 < 50 days) in aerobic natural water/sediment systems based on the available laboratory incubations. Metabolite DCSA as a major metabolite was formed. Dicamba basically did not partition to sediment during the study, only a small percentage ( 6.0 %) was recovered from the sediment phase. The majority of the DCSA formed was also found in the water phase. Mineralisation to carbon dioxide accounted for % AR, while residues not extracted from the sediment represented % AR at the end of the study. The potential for groundwater exposure from the representative uses by dicamba or the metabolite DCSA above the parametric drinking water limit of 0.1 µg/l was concluded to be low in geoclimatic situations that are represented by the relevant FOCUS groundwater scenarios. Based on its physical-chemical properties, dicamba has a potential for volatilization. A study investigating the volatilization of dicamba from soil surface or plant leaves indicated that negligible volatilization is expected from these surfaces. However, the estimated atmospheric half-life is longer than 2 days (DT 50 = 3.6 days; calculated with the AOP program, version 1.85). Therefore, based on this calculation, there is a potential for long-range transport through the atmosphere. The predicted environmental concentrations (PEC) in soil, surface water, sediment and groundwater for the representative uses assessed (considering FOCUS, 2001 and FOCUS, 2000) can be found in Appendix A. It is noted however that several input parameters used for the PEC calculations were reevaluated during the peer-review and in case of the groundwater simulations lower (< 20 %) dose rates were used. These are also indicated in Appendix A where appropriate. Some information that could clarify the reliability of the degradation parameters for the metabolite DCSA is missing, therefore data gaps were identified for this information. Furthermore, since the available calculations for pasture assume only established grassland and these PEC calculations do not cover the use of dicamba on newly established pasture where the crop interception would be much lower, a data gap was identified for PEC assessments for newly established pasture. 5. Ecotoxicology The risk assessment was based on the following documents: European Commission (2002a, 2002b, 2002c), SETAC (2001), and EFSA (2009). The first-tier short-term and long-term TERs exceeded the Annex VI trigger values of 10 and 5 in the standard risk assessment scenarios for herbivorous and insectivorous birds for all representative uses. The acute TERs for herbivorous and insectivorous birds were less than 10 for the use on pasture. For the use on maize the acute TER for insectivorous birds exceeded the Annex VI trigger of 10, but failed the trigger of 10 (TER = 9.1) for herbivorous birds. The long-term end point of 186 mg a.s./kg bw/day proposed in the original DAR was revised following re-evaluation of the effects data by the RMS (see revised DAR Volume 3 B of October 2010; Denmark, 2010). In an expert meeting (PRAPeR TC 49 in October 2010) the re-evaluation of the RMS resulting in a reduced NOEC (800 mg/kg feed) was agreed and it was confirmed that the end point of 89 mg a.s./kg bw/day should be used in the risk assessment. Nevertheless, the outcome of the risk assessment remained unchanged. The acute risk assessment for insectivorous birds was refined based on a body burden model as suggested in the PPR opinion on pirimicarb (EFSA, 2005). The calculation was modified but the deviations were considered acceptable. The maximum body burden was estimated for a skylark feeding on insects. The excretion half-life was assumed to be 5 hours based on observations of the metabolism of hens. The calculated body burden of 14.9 mg a.s./kg bw was less than the toxicity threshold of 21.6 mg a.s./kg bw (LD 50 of 9

10 216 mg a.s./kg bw divided by the trigger of 10). Therefore it was concluded that the risk to insectivorous birds is low. The acute risk assessment for herbivorous birds for the use on maize was refined with measured residues, resulting in a TER above the Annex VI trigger. The acute risk assessment for herbivorous birds for the use on pasture was refined following a body burden modelling approach analogous to that applied for insectivorous birds. In addition, measured residues were included in the refinement. The body burden of 17.5 mg a.s./kg bw was below the toxicity threshold of 21.6 mg a.s./kg bw. No avoidance was included in the calculation. Overall, it was concluded that the risk to herbivorous birds was sufficiently addressed by the available risk assessment. The first-tier acute and long-term TER values for herbivorous mammals exceeded the Annex VI trigger values for all representative uses, indicating a low risk. The long-term end point was revised. The end point of 150 mg a.s./kg bw/day was agreed in the meeting of experts (PRAPeR TC 49 in October 2010). The outcome of the long-term risk assessment remained unchanged. The metabolite 5-OH-dicamba was observed at a percentage of 65 % of the applied radioactivity in the metabolism study with plants. The risk from this metabolite to herbivorous birds and mammals was considered to be covered by the risk assessment for dicamba since there were indications in the mammalian toxicology studies that the metabolite is not of higher toxicity than the parent compound (see section 2). The risk from uptake of contaminated water for birds and mammals was assessed as low according to EFSA (2009). Dicamba is toxic to aquatic organisms. The lowest end point was observed in a study with higher aquatic plants. The toxicity of the major metabolite DCSA was about one order of magnitude lower. The risk to aquatic organisms was assessed as low with FOCUS step 2 PECsw values. The toxicity of formulated dicamba was tested with Aphidius rhopalosiphi, Typhlodromus pyri, Chrysoperla carnea, Aleochara bilineata and Poecilus cupreus. The trigger of 2 was not met for T. pyri for the in-field risk. The off-field HQ value was calculated as 0.1 for T. pyri, indicating a low offfield risk. The in-field and off-field risk for T. pyri was assessed as low in an extended laboratory study (exposure on leaves). A high in-field risk for the reproduction of T. pyri was indicated but the risk for reproduction in the off-field area was assessed as low. Results from residue decline studies suggest that recolonisation of the in-field area is possible within less than one year. Overall, the risk to non-target arthropods was considered to be low. Herbicidal effects on vegetative vigour and emergence were investigated in tests with 4 dicotyledonous plant species and with 2 monocotyledonous plant species. The lowest ER 50 values were observed for sugar beet (Beta vulgaris). The TERs for effects on vegetative vigour were 1.8 and 2.4, based on PECs from spray drift at 1 m distance. An in-field no-spray buffer zone of 5 m is required to achieve TERs of 8.9 and 12, which are above the trigger of 5. The risk to bees, earthworms, soil micro-organisms and biological methods of sewage treatment was assessed as low for the representative uses evaluated. Depending on the outcome of the data gap for the identification/quantification of an unidentified group of soil transformation products in the section on environmental fate and behaviour, further assessments may be triggered in relation to possible soil metabolites that might be formed. 10

11 6. Overview of the risk assessment of compounds listed in residue definitions triggering assessment of effects data for the environmental compartments Dicamba and DCSA will exist in the environment as salts of both the carboxylic acid and phenol functional groups, but the risk assessment was completed for dicamba and DCSA Soil Compound (name and/or code) dicamba DCSA Persistence Low persistence Single first-order DT days (20 C, pf2 soil moisture) Low to moderate persistence Single first-order DT days (20 C, pf2 soil moisture) Ecotoxicology The risk of dicamba to earthworms and soil microorganisms was assessed as low. Acute toxicity to earthworms: > 480 mg a.s./kg dw soil (regulatory end point including a safety factor of 10 = > 48 mg a.s./kg dw soil). The risk of DCSA to earthworms was assessed as low. Acute toxicity to earthworms: > 1000 mg a.s./kg dw soil (regulatory end point including a safety factor of 10 = > 100 mg a.s./kg dw soil). 11

12 6.2. Ground water Compound (name and/or code) Mobility in soil >0.1 μg/l 1m depth for the representative uses (at least one FOCUS scenario or relevant lysimeter) Pesticidal activity Toxicological relevance Ecotoxicological activity dicamba Very high mobility K Foc ml/g No Yes Yes Toxic to aquatic organisms, end point driving the aquatic risk assessment: Myriophyllum spicatum E b C 50 > 0.45 mg a.s./l (regulatory concentration including a safety factor of 10 = mg a.s./l). The risk to the aquatic environment in surface water was assessed as low. DCSA Medium to slight mobility K Foc ml/g No No data submitted. No data needed. No data submitted. No data needed. Harmful to aquatic organisms, end point driving the aquatic risk assessment: aquatic invertebrates EC 50 = 89 mg/l (regulatory concentration including a safety factor of 100 = 0.89 mg/l). The risk to the aquatic environment in surface water was assessed as low. 12

13 6.3. Surface water and sediment Compound (name and/or code) dicamba DCSA Ecotoxicology Toxic to aquatic organisms, end point driving the aquatic risk assessment: Myriophyllum spicatum E b C 50 > 0.45 mg a.s./l (regulatory concentration including a safety factor of 10 = mg a.s./l). The risk to the aquatic environment was assessed as low. Harmful to aquatic organisms, end point driving the aquatic risk assessment: aquatic invertebrates EC 50 = 89 mg/l (regulatory concentration including a safety factor of 100 = 0.89 mg/l). The risk to the aquatic environment was assessed as low Air Compound (name and/or code) dicamba Toxicology Harmful by inhalation. Rat LC 50 = 4.46 mg/l air (nose only) 13

14 LIST OF STUDIES TO BE GENERATED, STILL ONGOING OR AVAILABLE BUT NOT PEER REVIEWED Validation of the hydrolysis step for the plant method (relevant for the representative use on maize; submission date proposed by the applicant: unknown; see section 1). Method of analysis for products of animal origin (relevant for all representative uses evaluated; study available but not evaluated in view of the restrictions of Commission Regulation (EC) No. 1095/2007; see section 1). Further validation of the air method (relevant for all representative uses evaluated; an improved method is available however in view of the restrictions of Commission Regulation (EC) No. 1095/2007 new studies cannot be considered in the peer review; see section 1). Further information to confirm that the analytical methods used to generate the residue data on grass are able to release the conjugates (relevant for the representative use on pasture; submission date proposed by the applicant: unknown; see section 3). Further quantification and, if needed, identification of the unidentified group (referred to as Polar components) of soil transformation products formed in a soil incubation study (relevant for all representative uses evaluated; submission date proposed by the applicant: unknown; see section 4). Details regarding the kinetic analysis of the derivation of the degradation parameters (including formation fraction) for the metabolite DCSA in soil were not provided (relevant for all representative uses evaluated; submission date proposed by the applicant: unknown; see section 4). Details regarding the kinetic analysis of the derivation of the degradation parameters for the metabolite DCSA in water/sediment systems were not provided (relevant for all representative uses evaluated; new calculations are available in the Addendum Vol. 3; B.8 of October 2010 (Denmark, 2010), however they were considered not reliable by EFSA; see Evaluation Table open point 4.10 (EFSA, 2010) and section 4). PEC calculations for newly established pasture assuming more realistic crop interception for that situation (relevant for the representative use on pasture; submission date proposed by applicant: unknown; see section 4). PARTICULAR CONDITIONS PROPOSED TO BE TAKEN INTO ACCOUNT TO MANAGE THE RISK(S) IDENTIFIED Risk mitigation comparable to an in-field no-spray buffer zone of 5 m is required to protect nontarget plants in the off-field area (see section 5). ISSUES THAT COULD NOT BE FINALISED There is a data gap for the identification/quantification of an unidentified group of soil transformation products formed in a soil incubation study. Therefore there are no assessments for the environmental compartments for any potentially formed major or minor soil transformation products from this group that would trigger further evaluations. CRITICAL AREAS OF CONCERN Dicamba has the potential for long-range transport through the atmosphere. 14

15 REFERENCES ACD/ChemSketch, Advanced Chemistry Development, Inc., ACD/Labs Release: Product version: (Build 29305, 25 Nov 2008). Denmark, Draft Assessment Report (DAR) on the active substance dicamba prepared by the rapporteur Member State Denmark in the framework of Directive 91/414/EEC, February Denmark, Final Addendum to Draft Assessment Report on dicamba, compiled by EFSA, November EFSA (European Food Safety Authority), Opinion of the scientific Panel on Plant health, Plant protection products and their Residues on a request from EFSA related to the evaluation of pirimicarb. EFSA Journal 2005; 240: EFSA (European Food Safety Authority), Guidance Document on Risk Assessment for Birds and Mammals on request of EFSA. EFSA Journal 2009; 7(12):1438. EFSA (European Food Safety Authority), Peer Review Report to the conclusion regarding the peer review of the pesticide risk assessment of the active substance dicamba. European Commission, Guidelines for the generation of data concerning residues as provided in Annex II part A, section 6 and Annex III, part A, section 8 of Directive 91/414/EEC concerning the placing of plant protection products on the market, 1607/VI/97 rev.2, 10 June European Commission, Technical Material and Preparations: Guidance for generating and reporting methods of analysis in support of pre- and post-registration data requirements for Annex II (part A, Section 4) and Annex III (part A, Section 5) of Directive 91/414. SANCO/3030/99 rev.4, 11 July European Commission, 2002a. Guidance Document on Terrestrial Ecotoxicology Under Council Directive 91/414/EEC. SANCO/10329/2002 rev.2 final, 17 October European Commission, 2002b. Guidance Document on Aquatic Ecotoxicology Under Council Directive 91/414/EEC. SANCO/3268/2001 rev 4 (final), 17 October European Commission, 2002c. Guidance Document on Risk Assessment for Birds and Mammals Under Council Directive 91/414/EEC. SANCO/4145/2000. European Commission, Guidance document on the assessment of the relevance of metabolites in groundwater of substances regulated under Council Directive 91/414/EEC. SANCO/221/2000 rev. 10 (final), 25 February European Commission, 2004a. Guidance document on residue analytical methods. SANCO/825/00 rev. 7, 17 March European Commission, 2004b. Guidance document on Dermal Absorption. SANCO/22/200 rev. 7, 19 March European Commission, Review Report for the active substance dicamba finalised in the Standing Committee on the Food Chain and Animal Health at its meeting on 14 March 2008 in view of the inclusion of dicamba in Annex I of Directive 91/414/EEC. SANCO/829/08 rev.1, 7 March European Commission, Guidance document on the assessment of the equivalence of technical materials of substances regulated under Council Directive 91/414/EEC. Sanco/10597/2003 rev. 8.1, May FOCUS (2000). FOCUS Groundwater Scenarios in the EU review of active substances. Report of the FOCUS Groundwater Scenarios Workgroup, EC Document Reference SANCO/321/2000- rev pp, as updated by the Generic Guidance for FOCUS groundwater scenarios, version 1.1 dated April

16 FOCUS (2001). FOCUS Surface Water Scenarios in the EU Evaluation Process under 91/414/EEC. Report of the FOCUS Working Group on Surface Water Scenarios, EC Document Reference SANCO/4802/2001-rev pp. JMPR, Report of the Joint Meeting of the FAO Panel of Experts on Pesticide Residues in Food and the Environment and the WHO Core Assessment Group on Pesticide Residues Rome, Italy, September 2004, Report 2004, 383 pp. JMPR, Report of the Joint Meeting of the FAO Panel of Experts on Pesticide Residues in Food and the Environment and the WHO Core Assessment Group on Pesticide Residues Geneva, Switzerland, September 2007, Report 2007, 164 pp. SETAC (Society of Environmental Toxicology and Chemistry), Guidance Document on Regulatory Testing and Risk Assessment procedures for Plant Protection Products with Non-Target Arthropods. ESCORT 2. 16

17 APPENDICES APPENDIX A LIST OF END POINTS FOR THE ACTIVE SUBSTANCE AND THE REPRESENTATIVE FORMULATION Identity, Physical and Chemical Properties, Details of Uses, Further Information Active substance (ISO Common Name) Function (e.g. fungicide) Dicamba Herbicide Rapporteur Member State Denmark Identity (Annex IIA, point 1) Chemical name (IUPAC) Chemical name (CA) CIPAC No CAS No ,6-dichloro-2-methoxybenzoic acid 3,6-dichloro-2-methoxybenzoic acid EEC No (EINECS or ELINCS) EINECS; FAO Specification (including year of publication) FAO: 850 g/kg, (FAO Specification 85/TC, 2001) Minimum purity of the active substance as 850 g/kg manufactured (g/kg) Identity of relevant impurities (of toxicological, none environmental and/or other significance) in the active substance as manufactured (g/kg) Molecular formula C 8 H 6 Cl 2 O 3 Molecular mass Structural formula Cl O OH O Cl 17

18 Physical-chemical properties (Annex IIA, point 2) Melting point (state purity) Boiling point (state purity) o C (99.2%) Thermal decomposition starts at about 230 C before the boiling point is reached (99.6%) Temperature of decomposition Thermal decomposition starts at about 230 C, (99.6%) Appearance (state purity) PAI: White granular solid (99.2%) TGAI: Light cream/tan solid; granules, lumps and flakes (85.9%) Relative density (state purity) (99.2%) Surface tension = 63.7 mn/m (1.0 g/l aqueous solution) - Purity 89.8% Vapour pressure (in Pa, state temperature) Temperature: 25 o C. Purity: 99.2% 1.67 x 10-3 Pa (extrapolated) Henry s law constant (Pa m 3 mol -1 ) 1.0 x 10-4 Pa m³ / mol, Temperature: 25 o C Solubility in water (g/l or mg/l, state temperature) Temperature: 25 o C. Purity: 99.6% ph g/l ph 4.1 >250 g/l ph 6.8 >250 g/l ph 8.2 >250 g/l Solubility in organic solvents (in g/l or mg/l, state Temperature: 25 o C. Purity: 89.5% temperature) Acetone >500 g/l Ethyl acetate >500 g/l Methanol >500 g/l Octanol 490 g/l Dichloromethane 340 g/l Toluene 180 g/l Partition co-efficient (log P OW ) (state ph and temperature) Hexane 2.8 g/l Temperature: 25 o C. Purity: 99.6% ph ph ph Hydrolytic stability (DT 50 ) (state ph and ph 4: (50 C) stable temperature) ph 5: (25 C, 50 C) stable ph 7: (25 C, 50 C) stable ph 9: (25 C, 50 C) stable Dissociation constant Temperature: 25 o C. Purity: 99.2% UV/VIS absorption (max.) (if absorption > 290 nm state at wavelength) pka = 1.87 Purity: 99.2% solution wavelength [nm] molar extinction coefficient [L / mol cm] neutral neutral acidic acidic acidic acidic Maximum unreliable under alkaline conditions. No for absorbancy > 290 nm, but tailing to 350 nm. quantum yield is calculated Photostability (DT 50 ) (aqueous, sunlight, state ph) Temperature: 25 o C. Purity: 100% Water: 38.1d (ph 7) Quantum yield of direct phototransformation in = water at λ > 290 nm 18

19 Flammability Not highly flammable (purity: 89.8%) Explosive properties No explosive properties (purity: 89.8%) Oxidising properties Not oxidizing (purity: 89.8%) 19

20 Summary of representative uses evaluated for dicamba* Crop and/ or situation (a) Maize Pasture Member State or Country EU (N & S) EU (N & S) Product name Banvel 480 SL Banvel 480 SL F G or I (b) F F Pests or Group of pests controlled (c) Dicotyledon weeds incl. Chenopodium spp. Convolvulus spp. Polygonum spp. Dicotyledon weeds incl. Chenopodium spp. Convolvulus spp. Polygonum spp. Formulation Application Application rate per treatment Type (d-f) Conc. of as (i) SL 480 g/l SL 480 g/l method kind (f-h) overall spray overall spray growth stage & season (j) Postemergence until BBCH 16 Spring/ summer number minmax (k) interval between applications (min) kg a.s./hl min-max Water L/ha min-max kg a.s./ha min-max PHI (days) (l) Remarks: Period between treatment and harvest is > 100 days, no PHI is applicable [1] [2] weeks [1] [2][3] [1] Dicamba has the potential for long-range transport through the atmosphere. [2] A detailed quantification of a group of unidentified transformation products, found in one soil incubation, was not available, therefore there are no assessments for the environmental compartments for any potentially formed soil transformation products from this group. [3] The environmental exposure and risk assessment available for pasture covers only those situations when the pasture is already established. (m) For uses where the column "Remarks" is marked in grey further consideration is necessary. For uses where the column "Remarks" is marked in grey further consideration is necessary. Uses should be crossed out when the notifier no longer supports this use(s). (a) For crops, the EU and Codex classifications (both) should be taken into account; where relevant, the use situation should be described (e.g. fumigation of a structure) (b) Outdoor or field use (F), greenhouse application (G) or indoor application (I) (c) e.g. biting and suckling insects, soil born insects, foliar fungi, weeds (d) e.g. wettable powder (WP), emulsifiable concentrate (EC), granule (GR) (e) GCPF Codes - GIFAP Technical Monograph No 2, 1989 (f) All abbreviations used must be explained (g) Method, e.g. high volume spraying, low volume spraying, spreading, dusting, drench (h) Kind, e.g. overall, broadcast, aerial spraying, row, individual plant, between the plant- type of equipment used must be indicated (i) g/kg or g/l. (j) Growth stage at last treatment (BBCH Monograph, Growth Stages of Plants, 1997, Blackwell, ISBN ), including where relevant, information on season at time of application (k) Indicate the minimum and maximum number of application possible under practical conditions of use (l) PHI - minimum pre-harvest interval (m) Remarks 20

21 Methods of Analysis Analytical methods for the active substance (Annex IIA, point 4.1) Technical as (principle of method) HPLC-UV Impurities in technical as (principle of method) Plant protection product (principle of method) HPLC-UV HPLC-UV Analytical methods for residues (Annex IIA, point 4.2) Food of plant origin Food of animal origin Soil Dicamba and its salts and conjugated dicamba expressed as dicamba Dicamba and its salts and conjugated dicamba expressed as dicamba Dicamba, DCSA and their salts Water surface Dicamba, DCSA and their salts Air drinking/ground Dicamba, DCSA and their salts Dicamba Monitoring/Enforcement methods Food/feed of plant origin (principle of method and LOQ for methods for monitoring purposes) REM : Extraction was performed with 1 N hydrochloric acid and the extract was brought to > ph 8 by addition of 4 N potassium hydroxide. After centrifugation an aliquot is acidified and partitioned with diethyl ether. Dicamba is converted to dicamba methyl derivative by methylation with iodomethane. Extracts were cleaned-up using a silica gel column. Determination was performed by GC-MS using SIM. LOQ was 0.01 mg/kg for maize. Open for validation of the hydrolysis step. Open Food/feed of animal origin (principle of method and LOQ for methods for monitoring purposes) Soil (principle of method and LOQ) Dicamba: GC-MS (LOQ: 0.01 mg/kg) DCSA: GC-MS (LOQ: 0.01 mg/kg) Water (principle of method and LOQ) Drinking water: Dicamba: GC-MS (LOQ: 0.05 g/l) DCSA: GC-MS (LOQ: 0.05 g/l) 5-OH-dicamba: GC-MS (LOQ: 0.05 g/l)* Surface water: Dicamba: GC-MS (LOQ: 0.1 g/l) DCSA: GC-MS (LOQ: 0.1 g/l) 5-OH-dicamba: GC-MS (LOQ: 0.1 g/l)* Air (principle of method and LOQ) Body fluids and tissues (principle of method and LOQ) * Not a part of the residue definition for monitoring Open Not required as the active substance is not classified as toxic or very toxic. 21

22 Classification and proposed labelling (Annex IIA, point 10) with regard to physical/chemical data None 22

23 Impact on Human and Animal Health Absorption, distribution, excretion and metabolism (toxicokinetics) (Annex IIA, point 5.1) Rate and extent of oral absorption % (based on urinary (> 86%) and faecal (< 2 %) excretion as well as toxicokinetic measurements within 48 h) Distribution Potential for accumulation Rate and extent of excretion Widely distributed No evidence for accumulation Rapid and extensive, mainly via urine (87-99 %). Via urine >86 % within 24 h, < 2 % via faeces. Metabolism in animals Very limited metabolism. Unchanged excretion of % of applied dose; main metabolite DCSA ( %); demethylation of the methyl ether to the respective alcohol. Toxicologically relevant compounds (animals and plants) Toxicologically relevant compounds (environment) Dicamba and 5-OH-dicamba Dicamba Acute toxicity (Annex IIA, point 5.2) Rat LD 50 oral 1581 mg/kg bw R22 Rat LD 50 dermal > 2000 mg/kg bw Rat LC 50 inhalation 4.46 mg/l air/4h (nose only) R20 Skin irritation Slightly irritating Eye irritation Irritant R41 Skin sensitisation Non-sensitizer Short term toxicity (Annex IIA, point 5.3) Target / critical effect Relevant oral NOAEL Relevant dermal NOAEL Relevant inhalation NOAEL Liver (hepatotoxicity) (rat), haematology (rat, dog) decreased food intake and body weight gain (rat, dog) 90-day dog: 50 mg/kg bw/day 90-day rat: 479 mg/kg bw/day 28-day rat: > 1000 mg/kg bw/day No data available not required Genotoxicity (Annex IIA, point 5.4) Dicamba is unlikely to be genotoxic. Long term toxicity and carcinogenicity (Annex IIA, point 5.5) Target/critical effect Relevant NOAEL Decreased body weight gain 2-year, rat: 107 mg/kg bw/day 104-week, mouse: 121 mg/kg bw/day 23