To the Board of Directors of Clariant AG, Muttenz

We have been engaged to perform assurance procedures to provide limited assurance on sustainability indicators in relation to the sustainability reporting of Clariant AG and the consolidated subsidiaries (‚Clariant‘) for the year ended 31 December 2015.

Scope and Subject matter

Our limited assurance engagement focused on the following data and information disclosed in the online version of the 2015 Sustainability Report:

1. The quantitative 2015 sustainability indicators as summarized in the GRI content section and disclosed in the respective text boxes and marked with the label “ PwC”; and
2. The management and reporting processes to collect and aggregate the data as well as the control environment in relation to the data aggregation of these data.

Criteria

The reporting criteria used by Clariant are described in the internal reporting guidelines and define those procedures, by which the sustainability indicators are internally gathered, collated and aggregated. The internal guidelines are based on the G4 Sustainability Reporting Guidelines issued by the Global Reporting Initiative (GRI).

The accuracy and completeness of sustainability 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 Clariant’s internal guidelines, definitions and procedures on sustainability reporting. Further, the greenhouse gas quantification is subject to inherent uncertainty because of incomplete scientific knowledge used to determine emissions factors and the values needed to combine emissions of different gases.

Responsibilities and Methodology

The Board of Directors of Clariant is responsible for both the subject matter and the criteria as well as for selection, preparation and presentation of the information in accordance with the criteria. Our responsibility is to form an independent conclusion, based on our limited assurance procedures, on whether anything has come to our attention to indicate that the sustainability indicators are not stated, in all material respects, in accordance with the reporting criteria.

We planned and performed our procedures in accordance with the International Standard on Assurance Engagements (ISAE) 3000 (revised) ‘Assurance engagements other than audits or reviews of historical financial information’ and with ISAE 3410 ‘Assurance Engagements on Greenhouse Gas Statements’. These standards require that we plan and perform the assurance engagement to obtain limited assurance on the identified sustainability indicators marked with the label “ PwC”.

A limited assurance engagement is substantially less in scope than a reasonable assurance engagement in relation to both the risk assessment procedures, including an understanding of internal control, and the procedures performed in response to the assessed risks. Consequently, the nature, timing and extent of procedures for gathering sufficient appropriate evidence are deliberately limited relative to a reasonable assurance engagement and therefore less assurance is obtained with a limited assurance engagement than for a reasonable assurance engagement.

Independence and quality controls

We have complied with the independence and other ethical requirements of the Code of Ethics for Professional Accountants issued by the International Ethics Standards Board for Accountants, which is founded on fundamental principles of integrity, objectivity, professional competence and due care, confidentiality and professional behavior.

Our firm applies International Standard on Quality Control 1 and accordingly maintains a comprehensive system of quality control including documented policies and procedures regarding compliance with ethical requirements, professional standards and applicable legal and regulatory requirements.

Summary of work performed

Our limited assurance procedures included, but were not limited to the following work:

• Reviewing the application of Clariant’s internal guidelines
• Interviewing personnel responsible for the collection and reporting of the sustainability indicators at Clariant sites in the U.S.
• Performing tests on a sample basis of evidence supporting the sustainability indicators as outlined in the scope and subject matter section concerning completeness, accuracy, adequacy and consistency
• Inspecting the relevant documentation on a sample basis
• Reviewing and assessing the management reporting processes for sustainability reporting and consolidation and their related controls

We have not carried out any work on data other than outlined in the scope and subject matter section as defined above. We believe that the evidence we have obtained is sufficient and appropriate to provide a basis for our assurance conclusions.

Limited Assurance Conclusion

Based on the procedures we performed, nothing has come to our attention that causes us to believe that

1. The quantitative 2015 sustainability indicators of Clariant as described in the scope and subject matter section are not prepared and disclosed in all material respects in accordance Clariant’s internal guidelines and procedures and the underlying GRI G4 Sustainability Reporting Guidelines; and
2. The management and reporting processes to collect and aggregate the data as well as the control environment in relation to the data aggregation are not functioning as designed.

Basel, 15 April 2016

PricewaterhouseCoopers AG