377 56-1 ONE REPORT 2023 Assurance Report KPMG Phoomchai Audit Ltd., a Thai limited liability company and a member firm of the KPMG network of independent member firms affiliated with KPMG International Cooperative ("KPMG International"), a private English company limited by guarantee. All rights reserved. • GRI 414-2 Negative social impacts in the supply chain and actions taken (2016) • GRI 11.1.5 Flared and Vented Hydrocarbon (2021) • GRI 11.8.3 Number of process safety events, by business Activity (2021) Criteria The Subject Matters were assessed according to the following criteria: • The Sustainability Reporting Standards of the Global Reporting Initiative (“GRI Standards”) • The Global Reporting Initiative “GRI 11” Sector Standard for Oil and Gas Directors’ and management’s responsibilities The directors and management of IRPC are responsible for the preparation and presentation of the Subject Matters, specifically ensuring that in all material respects the Subject Matters are prepared and presented in accordance with the Criteria. This responsibility also includes the internal controls relevant to the preparation of the Report that is free from material misstatement whether due to fraud or error. Procedure performed In forming our limited assurance conclusion over the Subject Matters, our procedures consisted of making enquiries and applying analytical and other evidence gathering procedures including: • Interviews with senior management and relevant staff at corporate and operating sites; • Inquiries about the design and implementation of the systems and methods used to collect and process the information reported, including the aggregation of source data into the Subject Matters; • Inquiries about managements practices and procedures related to identifying stakeholders and their expectations, determining material sustainability matters and implementing sustainability policies and guidelines; • On-site visit at Head Quarter in Bangkok, and ETP Petrochemical, UHV Petroleum, CHP1 Power Utility plants in Rayong, selected on the basis of risk analysis including the consideration of both quantitative and qualitative criteria; • Agreeing the Subject Matters to relevant underlying sources on a sample basis to determine whether all the relevant information has been included in the Subject Matters and prepared in accordance with the Criteria. The procedures performed in a limited assurance engagement vary in nature and timing from, and are less in extent than for, a reasonable assurance engagement and consequently the level of assurance obtained in a limited assurance engagement is substantially lower than the assurance that would have been obtained had a reasonable assurance engagement been performed. Accordingly, we do not express a reasonable assurance opinion. Inherent limitations Due to the inherent limitations of any internal control structure it is possible that errors or irregularities in the information presented in the Report may occur and not be detected. Our engagement is not designed to detect all weaknesses in the internal controls over the preparation and presentation of the Report, as the engagement has not been performed continuously throughout the period and the procedures performed were undertaken on a test basis. Restriction of use of our report Our report should not be regarded as suitable to be used or relied on by any party wishing to acquire rights against us other than IRPC, for any purpose or in any other context. Any party other than IRPC who obtains access to our report or a copy thereof and chooses to rely on our report (or any part thereof) will do so at its own risk. To the fullest extent permitted by law, we accept or assume no responsibility and deny any liability to any party other than IRPC for our work, for this independent limited assurance report, or for the conclusions we have reached. KPMG Phoomchai Audit Ltd. Bangkok 14 March 2024
RkJQdWJsaXNoZXIy ODg4NTI=