Assurance

Our Corporate Assurance function has accountability and responsibility for providing internal assurance to the board that:

• Rio Tinto's policies, standards and controls are adequately designed and effective for their intended purpose; and that
• These policies, standards and controls are consistently implemented by all Rio Tinto sites on a timely basis and as designed.
  

In line with our policy on the rotation of external audit engagement partners, we have used the independent professional services firm PricewaterhouseCoopers to provide the board of directors of Rio Tinto plc and Rio Tinto Limited assurance on selected sustainable development subject matter.

The rules we use to define how we report data at the Group level can be found on the Our performance page and the definitions of the subject matter selected for assurance can be found in our Glossary.

PricewaterhouseCoopers' assurance statement satisfies the requirements of subject matters one through four of the ICMM assurance procedure; we have satisfied subject matter five of the ICMM assurance procedure through the Global Reporting Initiative's check of our GRI report.