The present invention generally relates to methods of using an air purifier to perform a photo-hydro-ionization (PHI) process to generate an oxidizer plasma to be exhausted into an indoor space. The oxidizer plasma may include ionized-hydro-peroxides (IHPs), superoxide, hydroxyl ions or some combination thereof (hereinafter generally referred to as IHPs). In one embodiment, the process sanitizes the ambient environment of the indoor space by purifying air, sanitizing hard surfaces, and decontaminating the environment by creating and maintaining an elevated level of IHPs at or above 0.02 parts per million (ppm) within the entire indoor space.
