The Tailings Management Facility (TMF) Safety Methodology is mainly based on the requirements and principles declared in “Safety guidelines and good practices for tailings management facilities” endorsed by the Conference of the Parties to the UNECE Convention on the Transboundary Effects of Industrial Accidents as well as other comparable international TMF standards. The TMF Safety Methodology is a powerful tool for the process of harmonizing technical standards for the entire life cycle of TMFs throughout the UNECE region. The Tailings Management Facility Safety Methodology, which consists of a Checklist for verifying the actual safety situation of tailings management facilities and the Tailings Management Facility Hazard and Risk Indexes (THI or TRI) for assessment of TMFs on regional, national and international basis.