Independent Assurance Report  on the Syngenta Corporate  Responsibility Reporting Main Assurance Procedures Subject matter Conclusions Responsibility and Methodology To the Head of Legal and Taxes, Syngenta AG,  Basel (‘Syngenta’) We have performed assurance procedures to  provide assurance on the following aspects of  the 2011 Corporate Responsibility (CR) reporting  of Syngenta. Data and information disclosed in the CR reporting  of Syngenta and its consolidated subsidiaries, for  the financial year ended December 31, 2011 and  with the indicated level of assurance as follows: Our assurance procedures included the  following work: In our opinion The accuracy and completeness of CR  performance indicators are subject to inherent  limitations given their nature and methods for  determining, calculating and estimating such data.  Our assurance report should therefore be read in  connection with Syngenta’s internal guidelines,  definitions and procedures on the reporting of its  CR performance. The Board of Directors of Syngenta AG is  responsible for both the subject matter and the  criteria. Our responsibility is to provide a  conclusion on the subject matter based on our  assurance procedures in accordance with the  International Standard on Assurance  Engagements (ISAE) 3000. For the subject matter for which we provide limited  assurance, the nature, timing and extent of  procedures for gathering sufficient appropriate  evidence are deliberately limited relative to a  reasonable assurance engagement. PricewaterhouseCoopers AG Basel, February 21, 2012 Gerd Tritschler David Pritchett Syngenta Annual Review 2011 59 Based on our work described in this report,  nothing has come to our attention that causes us  to believe that the data and information mentioned  in the subject matter and disclosed with the CR  reporting in the Syngenta Annual Review 2011  does not give a fair picture of Syngenta’s  performance in the area of CR. – The application of the Syngenta internal Health,  Safety and Environment (HSE) and Corporate  Community Investment (CCI) reporting  guidelines to the CR reporting with a  reasonable assurance; – The internal reporting system and procedures,  including the control environment, to collect  and aggregate CR data with a reasonable  assurance; and – The CR Performance Summary disclosed on  pages 54 to 57 of the Syngenta Annual Review  2011 with a limited assurance. Our assurance procedures do not cover the  indicators on capital expenditure, employee wages  and benefits, payments to suppliers, governments  and providers of capital, and economic value  retained presented in the CR Performance  Summary on page 54 of the Annual Review 2011. – The Syngenta internal HSE and CCI reporting  guidelines; and – The defined procedures by which the CR data  are gathered, collated and aggregated internally. Criteria – The internal HSE and CCI guidelines are being  applied properly; and – The internal reporting systems to collect and  aggregate CR data are functioning as designed  and provide an appropriate basis for its disclosure. – Evaluation of the application of group  guidelines – Site visits  – Assessment of the performance indicators  – Review of the documentation  – Assessment of the processes and  data consolidation Reviewing the application of the Syngenta  internal HSE and CCI reporting guidelines. Visiting the regional office of Syngenta in São  Paulo as well as a Crop Protection site and a  Seeds site in Brazil. The selection was based on  quantitative and qualitative criteria. Interviewing personnel responsible for internal  reporting and data collection at the sites we  visited and at the Group level. Performing tests on a sample basis of evidence  supporting the CR Performance Summary  relative to completeness, accuracy, adequacy  and consistency. Reviewing the relevant documentation on a  sample basis, including, management and  reporting structures and documentation. Reviewing the appropriateness of the  management and reporting processes  for CR reporting.  Assessing the consolidation process of data  at the group level.