This report provides IPCC guidelines to countries on how to estimate and report to the UNFCCC in their SF6 emissions from magnesium in their greenhouse gas (GHG) inventories. The IPCC methodology calculates SF6 emissions by assuming that all SF6 used as a cover gas is emitted to the atmosphere. Emission calculations at the plant level are based on SF6 consumption measurement. At the national level, a key issue is to account for all possible uses within the industry in a country. Another key reporting issue is the difficulty to obtain consumption data due to businesses' confidentiality concerns. This can be addressed by the rigorous use of standard reporting forms and background notes. It is also important for countries to implement quality assurance and quality control programmes at several steps in the process.