A sterilization, disinfection, sanitization, or decontamination system having a chamber defining a region, and a generator for creating a free radical effluent with reactive oxygen, nitrogen, and other species and/or a vaporizer. A closed loop circulating system without a free-radical destroyer is provided for supplying the mixture of free radicals from the generator mixed with the hydrogen peroxide solution in the form of the effluent to the chamber. The system is used in sterilizing, disinfecting, sanitizing, or decontaminating items in the chamber or room and, with a wound chamber, in treating wounds on a body. The wound chamber may be designed to maintain separation from wounds being treated. Various embodiments can control moisture to reduce or avoid unwanted condensation. Some embodiments can be incorporated into an appliance having a closed space, such as a washing machine. Some embodiments may include a residual coating device that deposits a bactericidal coating on sterilized items.