Sulphide ores form a significant component of world metal production. In the case of Nickel (Ni), 2018 saw 2.3 million tonnes of metal produced worldwide, with 60% being sourced from Ni-sulphide deposits. Sulphide ores are formed in reducing environments; thus they inherently oxidise during the mining process when exposure to air and water occurs. Both the metal oxide, and gaseous hydrogen sulphide products; formed during oxidation and resulting acidification, impact on the mining value chain. Metal oxides report to tails during processing, as processing circuits are optimised for the recovery of sulphides. The production of gases in closed circuit ventilation systems (such as underground mines or confined spaces) can produce irresistible atmospheres in working environments. The quantification of these risks is dependent on the reaction kinetics; determined by ore body geochemistry and interaction of the reactants over time. At the Savannah Nickel Deposit, Halls Creek Mobile Zone, Kimberly WA the impact on metal recovery of oxidation has historically been up to 10%. Whilst the production of SO2 has resulted in changes to ventilation of blind stopes, post firing and in one case the abandonment of fired stope material. Oxidation is managed at Panoramics Savannah Nickel mine through mining rates, stopes size, blast particle size, ventilation and ROM rotation. These measures act together along the value chain to increase total process efficiency, metal recovery and produce a safer work environment. CITATION: Vincent, C and Woodward, S, 2019. Oxidising value, in Proceedings Mining Geology 2019, pp 392395 (The Australasian Institute of Mining and Metallurgy: Melbourne).