(Question N EFSA-Q ) adopted on 14 December 2004

Transcription

1 Opinion of the Scientific Panel on Plant health, Plant protection products and their Residues on a request from EFSA on the appropriateness of using the current FOCUS surface water scenarios for estimating exposure for risk assessment in aquatic ecotoxicology in the context of Council Directive 91/414/EEC 1. (Question N EFSA-Q ) adopted on 14 December 2004 SUMMARY OF OPINION Aquatic risk assessment of plant protection products (PPP) is based on loadings to surface water through drift, runoff and drainage. The Commission has set up the FOCUS Surface Water (sw) Working Group (WG) to establish procedures for the calculation of Predicted Environmental Concentrations (PEC) to assess risks for aquatic ecosystems in the registration process according Directive 91/414/EEC. This Working Group developed a tiered approach to estimate the PECs. The Scientific Panel on Plant health, plant protection and their residues (PPR Panel) has been requested to evaluate these current FOCUSsw scenarios for estimating the exposure for risk assessment of some important non spray applications (NSAs) which are not thoroughly treated in the FOCUSsw calculations. The most important formulations involved in so called Non Spray Application (NSA) are granules and seed treatments. They can be applied broadcasted over the field (eventually followed by incorporation) and buried (precision application). Special cases are the so-called slow release granules and the coated seeds. A survey among the EU-member States indicated that no separate assessment is currently made for dust particles that may arise from these products in the course of application. There are also no established limits to ecotoxicological risk assessment for NSA formulations. Data on dust content are primarily requested with respect to human (operator) exposure risk assessment. The FOCUSsw WG did not consider entry of pesticide mass of NSAs into surface water via dust drift. Therefore the PPR Panel has developed procedures to estimate dust drift deposition of NSAs onto surface water. The PPR Panel does agree with the FOCUSsw WG that runoff and drainage are important entry routes for NSAs, but it proposes another parameterization of the model input for the entries of various NSAs than the current parameterization of the FOCUSsw WG. Adjusted input parameters are defined for the following types of NSAs: - broadcast application of granules needs an input of dust drift, 1 For citation purposes: Opinion of the Scientific Panel on Plant Health, Plant Protection Products and their Residues on a request of EFSA related to FOCUS sw scenarios. The EFSA Journal (2004)145, of 32

2 - for granules, seed treatments and coated seeds the runoff input parameters for the application method and the depth of incorporation have been re-defined, - for granules, seed treatments and coated seeds the drainage input parameter for the mixing depth is re-defined. This depth has a large effect on the extent of preferential flow and thus also on the leaching to surface water via drains - slow release granules and coated seeds are simulated by fractionating the application rates over a defined release time. Detailed procedures on the parameterization of NSAs for FOCUSsw tools are given in this document to improve the aquatic risk assessment of NSAs in the context of Council Directive 91/414/EEC. Key words : FOCUS surface water model, granular application, seed treatment, non spray application, PEC (predicted Environmental Concentration), drift, runoff, drainage, dust, CAM 2, DEPI 3, PRZM 4, MACRO 5. 2 CAM: Chemical Application Method 3 DEPI : DEPth of Incorporation (in cm) 4 PRZM: name of a model used for estimation of run off in FOCUS surface water scenarios 5 MACRO: name of a model used for estimation of drainage in FOCUS surface water scenarios 2 of 32

3 TABLE OF CONTENTS Summary of Opinion... 1 Table of contents... 3 Background... 3 Terms of reference... 4 Assessment Introduction to non spraying applications of plant protection products Overview of current way of handling NSA in FOCUSsw Detailed guidance on improved way of handling NSA in FOCUSsw Dust drift evaluation Drainage evaluation Runoff evaluation...14 Conclusions and Recommendations...16 Documentation provided by EFSA to the PPR Panel...17 References...18 Acknowledgement...18 Appendix 1 : CIPAC test methods for NSAs...20 Appendix 2 : results of drift simulation study...23 Appendix 3. Description of all Chemical Application Methods and DEPth of Incorporation in the PRZM model...27 Appendix 4 : Instruction for running the FOCUS Surface Water Scenarios with input recommended by the PPR Panel in Tables 3, 6 and BACKGROUND During the first stage of the revision of existing active substances for their potential inclusion in Annex I of directive 91/414/EEC, aquatic risk assessment was based mainly in loadings to surface water through drift. This was the result of various circumstances: - Drift was considered by many Member States (MS) in their own registration procedures. - Validated models based on experimental data were available for some MS. - Many uses were generally submitted as intended and drift was deemed to represent a worst case of water loading among all of them. However, already in the first stage it was realised that for many uses, drift was not a concern and that other routes of water contamination may be more relevant (run off, drainage, volatilisation-deposition). Furthermore, it was recognised that spray drift tables used (from BBA 6 -DE) need to be up-dated and adapted to the needs of the European Union (EU) assessment. This motivated the Commission to set the FOCUS Surface Water (sw) Working Group. The objective of this group was to establish a procedure for the estimation of the concentration of the active substance of a Plant Protection Product to be used in the registration process in 6 BBA: Biologische Bundesanstalt für Land- und Forstwirtschaft or Federal Biological Research Center for Agriculture and Forestry. 3 of 32

4 the EU according to Directive 91/414/EEC. The work of this Working Group developed in two stages: - firstly, the inventory of possible mathematical models suitable for this task was done from 1994 through 1996, the report FOCUS (1997) Surface water models and EU registration of plant protection products dated secondly, the development of a tiered approach to estimate these PECs for the benefit of the registration was established. This second part was carried from 1997 through 2003, the report FOCUS (2001) FOCUS surface water scenarios in the EU evaluation process under 91/414/EEC, document SANCO/4802/2001-rev.2 final of May Tiered procedures for risk assessment to aquatic organisms and EU scenarios have been provided by this second part of FOCUS SW works. The necessary tables, software, guidance and documentation to apply this procedure up to Step 3 may be found in the above quoted web page. Further guidance to integrate these PECsw calculations in the complete aquatic risk assessment may be found in the Guidance Document on Aquatic Ecotoxicology. The guidance and models cover all routes of water loading by pesticides except volatilizationdeposition for which the results of FOCUS air are awaited as a new guidance document. In the meantime, cases have come up (such as substances intended only for seed dressing) in which the applicability of the FOCUSsw document has been queried. The Scientific Committee on Plants (SCP) adopted an opinion on the FOCUSsw guidance document on and the SCP proposed in its conclusions that the stepped approach should be adopted as soon as possible by the Commission. The opinion of the PPR Panel was requested by the PRAPeR 9 sector of EFSA (self-tasking) and its conclusions and recommendations will be provided to the European Commission, the Member States and notifiers in the process of the revision of the second stage of active substances under Directive 91/414/EEC. TERMS OF REFERENCE The PPR Panel is asked for an opinion on the appropriateness of using the current FOCUS surface water scenarios for estimating exposure for risk assessment in aquatic ecotoxicology, especially for those situations of no spray applications (for example seed dressings and granular formulations). ASSESSMENT 1. Introduction to non spraying applications of plant protection products 7 available at : 8 available at: 9 PRAPeR: EFSA team: coordination of the pesticide risk assessment peer review of active substances 4 of 32

5 The FOCUSsw WG developed ten scenarios to calculate how pesticide residues may enter surface water. Realistic worst case concentrations are calculated in three types of small waterbodies across the EU (ditch, stream, pond). Six scenarios are called Drainage scenarios, because after release of the pesticide, it may enter the neighbouring waterbody via spray drift deposition and water flow through drainage pipes. In the four Runoff scenarios pesticide may enter the water body via spray drift deposition and runoff plus erosion. FOCUSsw considers besides spray drift run-off and drainage as routes of entry but does not take into account aspects such as atmospheric deposition, dry deposition, colloid transport, discharge of waste water, ground water and accidents. FOCUSsw includes both runoff of pesticide in water and pesticide sorbed to soil particles; the pesticide in the water goes to the water layer and the pesticide sorbed to soil particles is added to the sediment. Because FOCUSsw is especially developed for spraying applications the question is thus if FOCUSsw can also be applied as a risk assessment tool for these NSAs. Aspects such as deposition by volatilisation are covered by FOCUS air (report under preparation). The FOCUSsw WG distinguished five different application types: (i) downward ground spray, (ii) air blast (for orchards), (iii) aerial application, (iv) soil incorporation and (v) granular application. The last two modes of application need to be used for Non Spray Applications (NSAs). In this document the PPR Panel has evaluated the guidance of the FOCUSsw WG regarding NSAs. To do so, the PPR Panel has made an inventory of the most important Non Spray Application techniques (Table 1) and has developed guidance for a correct simulation of these application types with the FOCUS sw scenarios. The question is related to some scientific aspects and applicability problems of FOCUSsw and especially to some specific situations of the mode of application of substances. Especially non spraying applications are involved: granular formulations and formulations used for seed treatments. Table 1 gives an overview of the main NSAs. Other types of NSA formulations, including fumigants, dustable powder (DP) or tablets, were not considered further in addressing this question. Liquid fumigants are also not considered in Step 3 FOCUSsw nor in this opinion due to the totally different conditions of application and characteristics. A granular formulation (GR) is a free-flowing solid product of a defined particle size range ready for use. In comparison to spray droplets granules are rather large particles. They are composed of carrier impregnated or treated with the active ingredient(s) and settle out of the air very quickly as compared to dusts and sprays. There can be, however, some possibility for dust drift during application of granules due to the small, dust-like particles that result from granules rubbing during packaging, shipping and application. In the context of this opinion the following terminology is used: - drift is the process by which liquid or solid particles are carried out of the treated area by wind or the air stream of the sprayer, - spray drift is drift of liquid particles applied via spray boom, - dust drift is drift of solid particles released during NSAs. Although little information is available, it cannot be said that all granules are totally dust-free and offer total drift control. The active ingredient(s) can be incorporated into the granular body or applied to the surface of the carrier. Normally the active ingredient(s) releases rather fast from the granules in soil under the presence of water. However, some formulations are designed to release the active ingredient(s) over prolonged time ( slow release-, controlled 5 of 32

6 release ). Broadcast application of small granules may cause more drift than large granules but also the density of the carrier should be considered. Seed treatment pesticides are applied as either dry powders, slurries or liquids which are mechanically mixed with seeds. Dry powder formulations tend to sift off the seeds readily and can drift more easily. Liquid treatments are fixed better and more difficult to remove from the seeds. Seed treatment can be done with special application equipment in seed company plants or on-farm in the planters box. Generally speaking they correspond to relatively low dosages, in the order of magnitude of g/ha. Another way of treatment is coated seeds. Granules and treated seeds can be applied in different ways which can have a different effect on the drift, runoff and leaching behaviour of the active ingredient: - broadcast with or without incorporation into the soil, - buried (for granules: with the seed). Broadcast granules or treated seeds may be deposited beyond the field margin. FOCUS sw did not consider this as a possible route of entry into surface water. In the incorporated application granules or seeds are broadcast onto the soil surface and then incorporated using a rototiller or other tillage equipment. This process does not incorporate all granules or seeds but leaves a small fraction of them at the surface: this is both due to inefficient mixing and in the case of bedded systems, the lack of incorporation in wheel tracks. This implies that some of the granules or seeds remain on top of the soil where they may be prone to runoff or drainage via macropores. Considering runoff there is some evidence that granules, if left on the soil surface, have a relatively large runoff potential (Wauchope, 1978 and Wauchope and Leonard, 1980). In a study with incorporated granules (Wauchope, et al., 2004) losses of incorporated granules are similar to those seen with surface applications. Granules buried with seed or buried seeds are considered to be all buried at a certain depth, i.e. no granules or seeds remain on top of the soil. Table 1: Main Non-Spraying Applications: Formulation type and application method Formulation type, CIPAC code (see Appendix Application type 1) Granule (GR) Broadcast Broadcast + incorporated Buried with seed Slow release granules (CG) Broadcast Broadcast + incorporated Buried with seed Liquid seed treatment (LS, FS, ES, CS, SS, Broadcast WS) Broadcast + incorporated Buried with seed Seed treated with dry powder (DS) Broadcast Broadcast + incorporated Buried with seed Coated seeds (PS) Broadcast Broadcast + incorporated Buried : possible deposits beyond field margin not taken into consideration : in row, precision, also drilled or planted 6 of 32

7 2. Overview of current way of handling NSA in FOCUSsw The procedure for FOCUSsw consists of four steps, whereby the first one represents a very simple approach using first order kinetics and assuming a loading equivalent to a maximum annual application. The second step is the estimation of peak- and time-weighted concentrations taking into account a sequence of loadings. The third step focuses on more detailed modelling taking into account realistic worst case amounts entering surface water via relevant routes (runoff, spray drift, drainage). For step 3, 10 realistic worst-case scenarios for the compartment surface water have been defined, which collectively represents agriculture in the EU for the purposes of an assessment of the Predicted Environmental Concentration (PEC) in surface water. The last (4 th ) step considers substance loadings as foreseen in step 3 but it also takes into account the range of possible uses. The uses are therefore related to the specific and realistic combinations of cropping, soil, weather, field typography and aquatic bodies adjacent to fields. The models chosen in FOCUSsw for estimating the different routes of entry are MACRO for estimating the contribution of drainage, PRZM for the contribution of runoff and TOXSWA for the estimation of the final PECs in surface waters. An additional loading is defined as spray drift input. The calculation of the contribution of the spray drift is incorporated in the Graphical User Interface (GUI) for the surface water scenarios called SWASH (Surface WAter Scenario Help). This is a general software shell developed to ensure that the relevant FOCUS scenarios are being defined and input is defined consistently for all models. For NSAs different values for the different routes of entry are given depending on the step procedure. The first two steps are so simple that for dust evaluation step 3 is necessary as an acceptable practice. Each step gives a more realistic approach and the default values for runoff and drainage (10% for step 1 and 2 to 5% for southern and northern Europe for step 3) are replaced by calculated values (MACRO and PRZM model) in step 3. Drift is assumed to be 0% in all steps for all NSAs. Up to now the methods currently used in EU underestimate exposure because the runoff/drainage component is not included. This means that these methods were mainly or only based on drift aspects. Because the FOCUSsw WG considers drift to be zero for NSA it can be stated that the previous EU methods were not applicable for these types of application. The FOCUSsw WG concluded that the application types soil incorporation and granular application both resulted in no spray drift deposition onto the surface water. The remaining application types ground spray, air blast (for orchards) and aerial application are coupled to deposition numbers as determined by the FOCUSsw WG. For ground spray and air blast the deposition numbers depend on crop type and sometimes crop growth stage. Table 2 gives an overview of the way FOCUSsw handles NSA. Table 2. Overview of NSA types in the current FOCUS step 3 calculations and which entry route is taken into account by FOCUSsw Entry route Spray drift Drainage Runoff/erosion deposition Granules No Yes Yes Soil incorporated (seeds and granules) No Yes yes 7 of 32

8 3. Detailed guidance on improved way of handling NSA in FOCUSsw In this section the PPR Panel develops an alternative parameterization of the FOCUS sw scenarios for the NSAs mentioned in Table 1. The PPR Panel only considers the so-called step 3 FOCUS scenario calculations, so it did not consider the step 1 and step 2 FOCUS sw calculations. The PPR Panel has divided the entry routes into several groups based on the assumption that the route is considered as not relevant route (quotation 1 in the tables) or relevant (quotation 2). Depending of the applicability of FOCUSsw the quotation 2 is subdivided into 2a if it can not be covered by FOCUSsw (in which case a new development is needed), 2b if it can be covered by FOCUSsw as it stands or if it can be handled by FOCUSsw with adjustment of the normal inputs. In the last case details will be given for the specific inputs. 3.1 Dust drift evaluation Formulations for NSA must meet some quality specifications for registration. Although this is for EU countries a national matter most of the national registration procedures refer to the FAO and WHO specifications for pesticides. For NSA formulations suitable tests (CIPAC 10 methods) are available and described in Annex 1. Some of these tests are used as limits by some MSs (Estonia, Germany) but not for the evaluation of dust drift. A survey on dry formulations was directed to the 25 EU Member States (MS) with particular request for information on dust measurement from notifiers for the evaluation of plant protection products and on the establishment of limits that must be satisfied before authorisation. Twelve MSs have answered to these questions. There are no generally accepted criteria for dust evaluation in granular and seed dressing formulations. The acceptability of plant protection products containing dust is taken into consideration during the human health evaluation by an assessment of the operator exposure. According to the survey response of the Federal Office of Consumer Protection and Food safety (BVL) Department for Plant Protection Products (Germany) authorised products in Germany never reach a dust content of 1 µg/g. It can be concluded that methods are available to assess dust content and size distribution of dust particles in various types of formulations but there are no generally used values or requirements which refer to the dust drift during application. The Commission FOCUSsw Working Group concluded that the application types soil incorporation and granular all resulted in no spray drift deposition onto the surface water (resulting in a 1 case in Table 3). However, it is the opinion of the PPR Panel that not all NSAs behave in such a way that no drift occurs, especially when dust drift is considered. If, by expert judgment (based on experimental results or on a limit value for dust content), it is concluded that some NSAs do result in deposition of pesticide mass onto the water surface, SWASH 11 cannot handle this. However TOXSWA 12 could handle this, in the form of a socalled non-focus run in the TOXSWA shell (but which would in fact be a step 4 FOCUS run in those cases). So, in those cases a classification would result. In Table 3 a survey is given for the drift evaluation of NSAs. If drift or dry deposition must be taken into account for NSAs, the deposition must also be multiplied by a factor 1.2 for stream scenario in TOXSWA 10 CIPAC: Collaborative International Pesticides Analytical Council 11 SWASH: Surface WAter Scenarios Help 12 TOXSWA: Toxic substances in surface water 8 of 32

9 due to upstream catchment (section of FOCUSsw) as a worst case approach taking into account the same assumptions as for drift. Table 3: Guidance on the applicability of FOCUSsw 3 for granular and seed treatment formulations with respect to drift Formulation type Application method FOCUSsw applicability for dust drift* 1 2a Granular - Broadcast (with and without incorporation) - Buried with seed Seed treatment - Broadcast (with and without incorporation) - Buried with seed 1 Coated seeds - Broadcast (with and without incorporation) 1 - Buried 1 *1: not relevant route 2: relevant route a: not covered by FOCUSsw; new development needed b: covered by FOCUSsw as it stands c: can be handled by FOCUSsw with adjustment to normal inputs (see details in text) Although dust drift during application of treated seeds is considered by the PPR Panel to be a possible relevant route of entry it is not possible to be handled this by FOCUSsw due to the lack of any information about dust measurement methods and dust formation criteria during application. So, other approaches are needed instead of FOCUSsw for the evaluation of this route (resulting in a 2a quote in Table 3) The approach for broadcasting granules is based on the following assumptions: - According to the test selected the maximum dust content of the formulation available to drift could be: a. 0.1% (MT 171) b. 4% (MT58) c. any other % according to other available information - No data are available on the concentration of the a.i. in the dust. Therefore for the example calculations in Table 4 and Appendix 2 it is assumed that the dust has the same a.i. concentration as the granular formulation. If the concentration of the a.i. in the dust fraction is different from the a.i. content in the granule a correction factor must be applied accordingly. - If dust drift deposition curves can be obtained from a physical model comparable with the drift deposition curves evaluating spray drift, then it is possible that these results can be entered in FOCUSsw as scenario. - The PPR Panel wants to raise a concern about possible formation of extra dust drift due to the influence of ejection and spreading forces during application of the granules. If this is the case the input values must be adapted accordingly. For this last assumption the PPR Panel has adapted and applied two known spray drift models from the Netherlands (Holterman, 2004) and the United Kingdom (Miller, 2004) under well defined worst case conditions. These can be summarized as follows: - the release of the granules can be done by a spinning disc or by a boom spreader (downward position), 9 of 32

10 - specific conditions are fixed for height (50 cm), wind speed (5m/sec), wind stability conditions (unstable), swath width (12 m) and full field conditions. Simulations are performed for dust particles of respectively 250, 150, 100, 75, 50, 25 and 10 µm. The output characteristics of the calculations are expressed as % of the application rate in such a way that they can be introduced as input values for FOCUSsw. Simulations based on the IDEFICS spray drift model from The Netherlands (Holterman, 2004) demonstrate that larger particles settle relatively soon and no particles are deposited at a distance further than 10 m. Small particles of 10 µm have much slower deposition and their movement is mainly governed by wind profile and turbulence rather than by particle size (Appendix 2). The results indicate that the deposits from a boom spreader application are always higher than from a spinning disc application. This is mainly due to the fact that the spinning discs are spaced 12 meter apart and that the effective distance from the source to the water surface is larger. When comparing the results of dust deposition with spray droplets several factors must be taken into account: (1) the dust simulations with a spinning disc applicator give an initial horizontal velocity to the particles which is much greater than the downwards spray nozzle applications of a liquid, (2) dust deposits are only calculated for a single size but the relative amount of the particles of this size in a dust is not known and for small particles is often very small, sometimes making the problem of downwind dust deposition rather hypothetical, and (3) the dust particles do not reduce their mass after application in contrast to the drying up of spray droplets during transport in the air. Drift simulations by a model of the Silsoe Research Institute (UK) (Miller, 2004) give largely similar results. Although there are some differences the results confirm the above mentioned conclusions. In general the results of the IDEFICS model (Holterman, 2004) give higher deposits than the simulation results of Miller (2004), especially for the larger particles (250µm). Only the deposits on a pond for the boom spreader application are lower. These differences between the models are for various reasons. Both models are based on the same physical principles. However, they are very sophisticated and need many input parameters. Thus differences in model outcome as shown and discussed in Appendix 2 are not unexpected. If data on particle size distribution are available the PPR Panel proposes these values should be used for the calculation of dust drift according to the information in Appendix 2. Particle size distribution spectra can be subdivided into groups corresponding to the above mentioned classes of sizes and average drift deposits can be calculated on the three surface water bodies (ditch, stream, pond). If, however, no data on particle size distribution are available it is proposed that a worst case approach should be used, assuming that the granular formulation just passes test MT58, i.e.. exactly 4% of the particles (by weight) is smaller than 250 µm, 1% is even smaller than 150 µm, and 0.1% can be considered as dust (MT171). Consequently, 3% by weight has particle size between 150 and 250 µm. A realistic situation would be to assume that the 3% passing the 250 µm sieve but not the 150 µm sieve would consist of particles more or less evenly distributed with respect to size. For calculation purposes, this situation is roughly approximated by assuming 2% having size 250 µm and 2% having size 150 µm (1% slightly larger than 150 µm and 1% slightly smaller than this size). Particles smaller than about 50 µm behave rather similarly. It is reasonable to assume that dust represents particles smaller than 50 µm. For calculation purposes any size will do, so assume dust consists of 10 µm particles only. Obviously the dust fraction passes the 150 µm sieve, so the fraction of about 150 µm should be 1.9% to sum up all fractions smaller than 250 µm correctly to 4% of 32

11 For the most extreme situation (average wind speed: 5 m/s; neutral stability; release height: 0.5 m; bare ground) the calculations of the off-target deposition onto water bodies defined by FOCUSsw for this hypothetical worst case formulation are given in table 4. More details and informations on the specific conditions of the simulation are described in Appendix 2. The figures in table 4 are obtained from the theoretical calculations for the case of the hypothetical granule (with worst case properties) as described above. Downward deposits for a boom spreader are higher than for a spinning disc technique since the outmost point of release on a boom spreader is close to the field edge, while the outmost spinning disc is half a swath (e.g. 6 m) upward from the field edge. The simulation by P. Miller (2004) results in lower values for the spinning disc application and similar values for boom spreader application (except for the pond surface water giving higher values probably due to the fact that some particles are better captured on the wide surface of the pond and can not escape to the downwind side which is the case for the smaller ditch or stream surfaces). The drift of a typical spray drift was also calculated under the same conditions and with the same calculation method in order to compare both types of drift. Comparison of these spray drift results (Table 4) with the dust drift values gives analogous results and conclusions. Table 4: Deposition by the Spray Models (Holterman, 2004; Miller, 2004) and FOCUS Drift Calculator expressed in % of applied dosage as a.i. at water surface of FOCUS ditch, stream and pond. (Conditions for drift models: average wind speed: 5 m/s; neutral stability; release height: 0.5 m; bare ground; Conditions for calculations with FOCUS Drift Calculator: grass/alfalfa, 1 appl., i.e. 90%_ile probability of occurrence) Ditch Stream Pond (H.J. Holterman, 2004) Granular with spinning disc Granular with boom spreader Spray with boom sprayer (P. Miller, 2004) Granular with spinning disc Granular with boom spreader 1.49* 3.20* * 3.00* 1.24* 2.59* * 2.05* 0.15* 0.19* * 1.63* FOCUS Drift Calculator Spray with boom sprayer * based on the assumption that the a.i. concentration of the dust is the same as in the formulation or else these values must be corrected for the fraction of a.i. Calculation of spray drift deposition by the FOCUS Drift Calculator for comparable conditions (grass/alfalfa and one application) results in clearly lower depositions onto the FOCUS ditch and stream and a comparable deposition onto the FOCUS pond (Table 4). In all calculations and by the FOCUS Drift Calculator the spray drift deposition has been integrated across the width of the water body (1 m for the ditch and stream and 30 m for the pond). The distance from the edge of the field up to the edge of the water body was 1.0 m for the ditch, 1.5 m for the stream and 3.5 m for the pond, which corresponds to the definitions in FOCUS, Because the conditions of the calculations are considered to be extreme it is the opinion of the PPR Panel that they can be expected to be very conservative, especially assuming that a wind speed of 5m/s is the upper speed for Good Agricultural Practice in the EU. This is also stated in some guidelines for measuring drift (BBA, 1992) 11 of 32

12 The PPR Panel concludes that dust drift may be as important as spray drift and that the dust drift deposition should be included in the assessment. Despite the differences between the models for drift evaluation this does not change the opinion that dust drift must be taken into account as a possible entry route in FOCUSsw. The PPR Panel recommends to use the highest figures from each of the two models as a first tier approach. If this results in unacceptable risk, it is recommended (1) to perform more detailed calculations with one of the models and to include in the assessment a justification or (2) to perform calculations based on experimental data. Dust drift estimates can be entered as a scenario and calculated according to the information given in Appendix 2. Technical guidance for the running of the FOCUSsw scenarios with this input is given in Appendix Drainage evaluation In the Step-3 FOCUS surface water scenarios, leaching via drainage pipes to surface water is calculated with the MACRO model. This model has four options for pesticide application which differ only from each other with respect to the parameterisation of interception of pesticide by the crop and the parameterisation of the mixing depth. - The crop interception is a correction factor for the amount of pesticide reaching the soil surface. In FOCUSsw Step 3 the crop interception is calculated by the PRZM and MACRO models; the pesticide on the plant surface degrades and is washed off the plants in these models. The crop interception can also be set to zero. - The mixing depth is the soil layer at the surface in which the pesticide is assumed to equilibrate before it can flow into the macropores. This implies that a small mixing depth leads to higher pesticide concentrations in the drain pipes than a large mixing depth. The four options are characterised in Table 5. Table 5: Interception and mixing depth values for input in MACRO Application Parameterisation of interception Parameterisation of mixing depth option in MACRO Ground Based on leaf area index for 0.1 mm spray annual crops and set to a predefined maximum for perennial crops Granular mm Incorporated 0 Option implying no interaction between solute in upper soil layer and water routed into macropores thus leading to considerable reduction of macropore transport Air-blast Set to a predefined maximum 0.1 mm percentage Aerial Based on leaf area index for annual crops and set to a predefined maximum for perennial crops 0.1 mm 12 of 32

13 Wauchope et al. (2004) found that runoff losses from incorporated granules were similar to losses from surface applications, possibly because some of the granules were still at the soil surface after the incorporation. If some of the granules are still at the soil surface, they may lead to leaching via macropores. The parameterisation of the MACRO option incorporated seems therefore not conservative enough for FOCUSsw Step-3 scenarios. As a consequence, we recommend use of the option granular for application methods where the pesticide is incorporated. Admittedly, this is a conservative approach because most of the granules will be incorporated and thus less available for flow through macropores. Table 6: Guidance on the applicability of FOCUSsw Step 3 for granular and seed treatment formulations with respect to drainage Formulatio Application n type method Granules Slow release granules Seed treatment Coated seeds - Broadcast - Incorporation - Buried with seed - Broadcast - Incorporation - Buried with seed - Broadcast - Incorporation - Buried with seed - Broadcast - Incorporation - Buried FOCUSsw applicability for drainage 2b 2b 2b Recommended application option in MACRO Granular granular incorporated Granular granular incorporated Granular granular incorporated Granular granular incorporated 1: not relevant route 2: relevant route a: not covered by FOCUS; new development needed b: covered by FOCUS as it stands c: can be handled by FOCUS with adjustment to normal inputs Recommended application frequency in MACRO for a single application single single single for all methods, split into 8 applications distributed over intended protection period (as determined by properties of formulation) single single single for all methods, split into 8 applications distributed over germination period (e.g. 8 days) FOCUSsw uses first order kinetics (DT50 values) for degradation of the substances. Both PRZM and MACRO assume that the rate of degradation decreases with depth in the soil profile and have default values for adjustment of degradation rate with soil depth. In most cases there is no scientific reason why the degradation kinetics for granular applications would differ significantly from normal spraying or incorporated deposits. Only in the case of slow-release granules and coated seeds may a significant effect may occur: it may lead to either more or less leaching depending on the scenario characteristics. For slow release granules and coated seeds it is recommended distribution of the single dose be simulated over more fractionated applications within the period for which the controlled release (CR) application is considered to be protective from an agricultural point of 13 of 32

14 view. This approach must be a reasonable assumption and is more a case by case situation based on the efficacy documents of the manufacturer. For seed treatments the number of applications must again be divided over the germination period of the seed. It is again recommended distributing the single dose over 8 application times to simulate a slow release as described before. These considerations lead to the guidance for the MACRO parameterisation in FOCUSsw Step-3 scenarios in Table 6. Technical guidance for running of the FOCUSsw scenarios with this input is given in Appendix Runoff evaluation In FOCUS sw the PRZM model is used for calculating runoff entries into surface water. The PRZM manual (Carsel et al., 1995) makes clear that concentrations in runoff water are very sensitive to the way the pesticide is initially placed in the soil as well as to the depth of placement in the soil. Up to a depth of 2 cm pesticide is extracted for runoff, the extraction model employs an exponentially decreasing curve with depth to restrict the mass of dissolved phase pesticide that is allowed to mix with runoff water. Way and depth of placement in the soil are defined by the CAM and DEPI parameters, respectively. CAM stands for Chemical Application Method and DEPI stands for DEPth of Incorporation (in cm). The PRZM model offers eight possible applications methods (CAMs, see Appendix 2) of which six can be used in the FOCUS_PRZM_SW_1.1.1 model. The default option in FOCUS is CAM=1, corresponding to surface applications with residues being distributed up to 4 cm deep in a linearly decreasing way. Relevant CAM values for the NSA in FOCUS sw are CAM=1, CAM=6 and CAM=8. Table 7 gives a description of these CAM values. Table 8 gives an overview of the recommended parameterization of PRZM for the specified Non Spraying Applications for the FOCUS Surface Water Scenarios calculations. For broadcasted applications, without soil incorporation, the PPR Panel advises DEPI = 1, which implies a more worst case loading than the FOCUS default with DEPI=4. This is in agreement with findings of Wauchope (1978) and Wauchope and Leonard (1980) who found evidence for relatively large runoff potential for granules left on the soil surface. The CAM value CAM=4 (Uniform incorporation into the soil to a depth specified by the user) is recommended for rototil incorporation in the PRZM manual. This CAM has NOT been selected for the application method Broadcast+incorporated because the PPR Panel judged it to be not conservative enough for granules which in a broadcast application will be on the surface and partly remain there (see section 1.1). Wauchope et al., 2004 observed losses of incorporated granules similar to those seen with surface applications. That is why CAM=6, DEPI=4 (equal to CAM=1, FOCUS default) have been selected. The DEPI value for applications buried with seed is the seed depth. For CAM=8 and DEPI is smaller than 2 cm pesticide will be extracted and pesticide runoff will occur. However, for CAM=8 and DEPI is larger than 2 cm. no pesticide runoff will occur as no pesticide is present in the soil up to 2 cm depth of 32

15 Table 7. Description of the Chemical Application Method options in PRZM with values of CAM=1, 6 and 8 (Carsel et al., 1995), relevant for NSA in FOCUS sw. For more details see Appendix 2 CAM value Description CAM=1 Recommended for surface applications. Residues are distributed to 4 cm, linearly decreasing with depth. CAM=6 Similar to CAM=1 except that residues are linearly decreasing to a user defined depth. CAM=8 Recommended for shank injection. Residues are incorporated in a single compartment at the depth specified by the user. Table 8. Guidance for FOCUSsw step 3 or higher calculations with respect to runoff Formulation type Application method Recommended input Granules Slow release granules # Seeds treatment Coated seeds # Broadcast Broadcast + incorporated Buried with seed Broadcast Broadcast + incorporated Buried with seed Broadcast Broadcast + incorporated Buried with seed Broadcast Broadcast + incorporated Buried FOCUS sw applica bility for runoff * CAM=6, DEPI=1cm CAM=6, DEPI=4cm CAM=8, DEPI=seed depth CAM=6, DEPI=1cm CAM=6, DEPI=4cm CAM=8, DEPI=seed depth CAM=6, DEPI=1cm CAM=6, DEPI=4cm CAM=8, DEPI=seed depth CAM=6, DEPI=1cm CAM=6, DEPI=4cm CAM=8, DEPI=seed depth *: 1: not relevant route 2: relevant route a: not covered by FOCUS; new development needed b: covered by FOCUS in its standard step 3 mode c: can be handled by FOCUS with adjustment to default inputs (see column 4) Recommended application frequency in PRZM for a single application Single Single Single for all methods, split into 8 applications distributed over intended protection period (as determined by properties of formulation) Single Single Single for all methods, split into 8 applications distributed over germination period (e.g. 8 days) 15 of 32

16 Slow Release or Controlled Release (CR) granules release chemicals more slowly than conventional granules and under worst-case conditions of rainfall immediately after application they should exhibit lower runoff. (Davis et al., 1996). So, under those conditions conventional granules would give more runoff than CR granules. Hence, treating CR granules the same way as conventional granules would imply a conservative approach. However not all FOCUS scenarios experience the worst case conditions of rainfall immediately after application; the rainfall can also occur later on. Therefore it is recommended for CR granules the single dose should be distributed over e.g. 8 application events within the period for which the CR application is considered to be protective from an agricultural point of view. This approach must be a reasonable assumption and is more a case by case situation based on the efficacy documents of the manufacturer. For seed treatments the number of applications must be divided over the germination period of the seed. Technical guidance for running of the FOCUSsw scenarios with this input is given in Appendix 4. CONCLUSIONS AND RECOMMENDATIONS The objective of the Commission FOCUS Surface Water (SW) Working Group was to establish a procedure for the estimation of the concentration of the active substance of a Plant Protection Product to be used in the registration process in the EU according to Directive 91/414/EEC. The Commission has submitted FOCUSsw as a tool for the calculation of predicted environmental concentrations in surface water (PECsw) to be used for the risk assessment of aquatic organisms for substances in the 3 rd stage of the procedure of the Peer review. FOCUSsw considers besides spray drift also run-off and drainage as routes of entry. Because FOCUSsw is especially developed for spraying applications the question is thus if FOCUSsw can also be applied as a risk assessment tool for non spray applications (NSAs). The PPR Panel is specially asked to consider situations where, due to the type of application (seed dressing, granular ), spray drift does not represent the main route of possible surface water contamination. For drift evaluation it can be concluded that: 1. The PPR Panel identified dust in NSA to be a relevant route of exposure for surface water. Currently, dust formation is estimated by the CIPAC MT171 & MT58 methods but these results are only used for human exposure assessment during handling of NSAs. 2. For dust as possible source of surface water contamination there are no generally accepted tests or criteria. 3. The PPR Panel agrees with the FOCUSsw WG that drift is a non relevant route for granules and seed treatment applied in furrow and buried immediately, and for coated seeds of 32

17 4. However broadcast granular applications even with subsequent incorporation can form dust drift which can have comparable effects as spray drift. This can be handled by FOCUSsw with adjustment of the normal default inputs in such a way that an evaluated dust drift value is entered. For default values, adapted spray drift models can be used to estimate dry deposition from dust by taking into account a number of specific underlying criteria. 5. Broadcast application of treated seeds (with and without subsequent incorporation) is considered to be a relevant route of drift but can not be handled by FOCUSsw without further development. Runoff can be an important route of entry in surface water. Depending on both the formulation type and the application method it is possible to use the FOCUSsw model for that purpose. However it is necessary to alter the current parameterisation of the PRZM model: CAM (Chemical application method) and DEPI (depth of incorporation) as suggested in Table 8. Drainage is also an important and relevant route of entry. It is possible to handle this route by FOCUSsw but depending on the formulation type this has to be done in one of two different ways: 1. Granules and treated seeds can be handled by FOCUSsw as it stands 2. Incorporation of the granules and treated seeds does not exclude the presence of particles at the soil surface and the parameter of mixing depth has to be adjusted accordingly as suggested in Table 6 For both runoff and drainage slow release formulations and coated seeds can only be handled by FOCUSsw with adjustment of the application in fractionated application dosages. Therefore, we recommend the single dose be distributed, on a case to case specific way by a series of fractionated doses over a certain time. (Tables 6 and 8). DOCUMENTATION PROVIDED BY EFSA TO THE PPR PANEL 1. Letter from EFSA requesting a consultation on the PPR Panel on the relevance of using the FOCUS surface water models. ref. D/2004 GP/md/253, 31 March Letter from T. Hardy on the acceptance of the PPR Panel question on the relevance of using the FOCUS surface water models. ref. ARH/CR, 23 April FOCUS (1997), Final report of the work of the Regulatory Modelling Working Group on Surface Water Models of FOCUS: Surface Water models and EU registration of plant protection products, 24 February 1997, pp FOCUS (2001), Report prepared by the FOCUS Working Group on Surface Water scenarios: FOCUS Surface Water scenarios in the EU evaluation process under Dir. 91/414/EEC, SANCO/4802/2001-rev.2 final May 2003, pp Guidance Document on Aquatic Ecotoxicology. Reference Sanco/3268/2001 rev 4. (final), 17 October 2002, p Scientific Committee on Plants (SCP) opinion on the FOCUS SW guidance document, 17 December Reference SCP/GUIDE-FOC-SW/002-Final, p of 32

18 7. EFSA internal documents on examples regarding the use of FOCUS sw for risk assessment taken in the Peer review of the second list of active substances, including evaluation tables. Reference EFSA/PRAPeR/13/ Holterman H.J., Off-target dust deposition from a spinning disc granule spreader, Calculations based on the IDEFICS spray drift model. Report 224. Agrotechnology and FOOD innovations, Wagenigen, The Netherlands. 9. Miller P., Personnel Communication. Silsoe Research Institute, UK. 10. BBA (Biologische Bundesanstalt Braunschweig or Federal Biological Research Center Braunschweig), In: Guidelines for plant protection equipment tests, Part VII. Appendix A: Measuring direct drift when applying liquid plant protection products outdoors. REFERENCES Carsel, R.F, Imhoff J.C., Hummel P.R., Cheplick J.M. and Donigian, Jr, A.S PRZM- 3. A Model for Predicting Pesticide and Nitrogen Fate in Crop Root and Unsaturated Soil Zones: Users Manual for release 3.0. National Exposure Research Laboratory, U.S. Environment Protection Agency, Athens, GA, USA. (available at Davis R.F., Wauchope R.D., Johnson A.W., Burgoa B., and A.B. Pepperman Release of Fenamiphos, Atrazine, and Alachlor into Flowing Water from Granules and Spray Deposits of Conventional and Controlled-Release Formulations. J. Agric. Food Chem. 44, 9, Wauchope, R.D The pesticide content of surface water draining from agricultural fields - a review. J. Environ. Qual., 7, Wauchope, R.D. and R.A. Leonard Maximum pesticide concentrations in agricultural runoff. A semiempirical prediction formula. J. Environ. Qual. 9, Wauchope R.D., Truman C.C., Johnson A.W., Sumner H.R., Hook J. E., Dowler C.C., Chandler L. D., Gascho G.J., and Davis J.G., Fenamiphos losses under simulated rainfall: plot size effects. Trans. Amer. Soc, Eng., 47, Manual on development and use of FAO and WHO specifications for pesticides First edition, Rome, ISBN: , p 272. SCIENTIFIC PANEL MEMBERS Damia Barcelo Culleres, Robert Black, Jos Boesten, Alan Boobis, Anthony Hardy, Andy Hart, Herbert Koepp, Robert Luttik, Kyriaki Machera, Marco Maroni, Douglas McGregor, Otto Meyer, Angelo Moretto, Euphemia Papadopoulou-Mourkidou, Ernst Petzinger, Kai Savolainen, Andreas Schaeffer, John Stentröm, Walter Steurbaut, Despina Tsipi-Stefanitsi, Christiane Vleminckx. ACKNOWLEDGEMENT The Scientific Panel on PPR wishes to thank Paulien Adriaanse, Alain Dubois, Henk-Jan Holterman, Nick Jarvis, Paul Miller and Don Wauchope for their contributions and the preparation of this draft opinion of 32