Destroys superoxide anion radicals which are normally produced within the cells and which are toxic to biological systems (By similarity). Involved in the metabolism of 4-aminophenol. May have an indirect role in hydroxyquinol metabolism by scavenging and detoxifying reactive species that promote its auto-oxidation (PubMed:20480210). 2 H(+) + 2 superoxide = H2O2 + O2 Binds 1 Fe cation per subunit. Optimum pH is 7.5. Monomer. Belongs to the iron/manganese superoxide dismutase family.