Our Annual Reports on Sustainability have been independently verified since 2005. External assurance of our 2021 reporting was conducted by Corporate Integrity Ltd. in accordance with the ICMM Mining Principles Assurance and Validation Procedure and the Copper Mark Assurance Process. Since 2009, external assurance has been completed multiple times at all active mining and metals processing operations. For the majority of our operations, we conduct site-level external assurance via this program at least once every three years and annually at PT-FI and Cerro Verde. Due to COVID-19 travel restrictions, virtual assurance was carried out during the first three quarters of 2021 in accordance with industry leading practices using a combination of video and online document sharing platforms and included ICMM and Copper Mark requirements (for copper producing sites). Safety conditions allowed on-site assurance reviews to resume in the fourth quarter of 2021. Our assurance schedule also supports the publication of our 2021 Annual Report on Sustainability.
Note: Comprehensive Virtual Reviews entail exhaustive analyses of evidence examples and in-depth virtual meetings with site-based and corporate-level subject matter experts. Desktop Reviews entail exhaustive analyses of evidence examples and select interviews with site-based and corporate-level subject matter experts, when clarifications are necessary.