Photochemical degradation of pollutants can occur through both direct and indirect processes. In the environment, reactive species such as superoxide, singlet oxygen and OH can participate in indirect photochemistry processes. OH is a particularly important radical generated in atmospheric and surface waters. Previous research has illustrated the importance of snow and ice to environmental chemistry processes; however the photochemical generation of reactive components is not well understood in snow and ice. Here we investigate the photochemical generation of OH from peroxide photolysis in snow and ice systems under environmentally relevant conditions.