This document provides a harmonized methodology for calculating GHG emissions from the ferro-alloys industry based on the mass balance approach. This document also provides key performance indicators over time for ferro-alloys plants. This document covers the following direct and indirect sources of GHG:— direct GHG emissions [see ISO 14064-1:2018, 5.2.4 a)] from sources that are owned or controlled by the company, such as emissions resulting from the following sources:— smelting (reduction) process;— decomposition of carbonates inside the furnace;— auxiliaries operation related to the smelting operation (i.e. aggregates, drying processes, heating of ladles, etc.);— indirect GHG emissions [see ISO 14064-1:2018, 5.2.4 b)] from the generation of purchased electricity consumed in the company’s owned or controlled equipment.