Assessing potential for movement of active substances and their metabolites to ground water in the EU
EC Document Reference Sanco/13144/2010 version 1
FOREWORD BY THE FOCUS STEERING COMMITTEE Since its beginning in 1993, FOCUS (FOrum for the Co-ordination of pesticide fate models and their USe) has established a number of work groups to develop procedures for estimating concentrations of plant protection products and their metabolites in various environmental compartments (ground water, surface water, soil, sediment, and air) and for performing kinetic analyses. The procedures for assessing potential movement to ground water became effective in December 2000 and have been used since then as part of the EU registration process. A few years after the release of the scenarios, scientific progress in the field of leaching models as well as experience with the use of the scenarios resulted in questions being raised regarding changes to the scenarios, harmonization of the different leaching models, the role of more advanced assessment approaches (for example, graphical information systems and non-equilibrium sorption), how to use the results of simulations and experimental studies (lysimeter and field studies) in the assessment, and the coverage of new EU member states by the FOCUS scenarios. Therefore FOCUS established a work group of experts from regulatory authorities, research institutes, and industry to develop revised scenarios and an overall framework for assessing leaching potential. This FOCUS group met as a whole 16 times between February 2004 and June 2008 and also many times in various subgroups. This report is the result of extensive deliberation on the numerous issues that arose after conducting a survey of the opinions of the member states. The output of the work group also includes a completely revised set of models, input and output shells, and scenarios which will become available at the FOCUS web site after approval of this report. The version control process does not allow access to the models for regulatory use prior to their official release date. Therefore, the FOCUS Steering Committee recommends the revised models can be used for leaching assessments immediately after release, but that registrants may use the models released in 2000 for submissions up to one year following the release of these models on the FOCUS web site. One of the specific details in the remit of the work group was that the revision of the scenarios would include harmonisation of the models (dispersion length, water balance, etc.). This effort was largely successful and the Steering Committee recommends that the ground water assessments can now be performed with any of the models (PEARL, PELMO, and PRZM) and there is no need to perform the assessments with more than one model.