An apparatus and method for sanitizing, decontaminating, deodorizing, conditioning, drying, treating, cleaning, modifying and / or otherwise improving an atmosphere within a container. The container can be a bag or other housing for equipment, food and / or suitable material. Ozone is generated within an atmosphere that is exposed to the materials. The generated ozone is mixed with the atmosphere. At least a portion of the generated ozone is then removed from the mixed atmosphere. The apparatus and method of this invention can be used to treat contaminated sports equipment and the like,_as well as to treat food storage atmospheres, such as those exposed to fresh fruits and vegetables.