Abstract: A disinfection system including an enclosed chamber and a source of a disinfecting vapor connected to the enclosed chamber, wherein the disinfecting vapor includes nitric acid. Methods of disinfecting a contaminated article are also described, the methods including placing the contaminated article within an enclosed chamber of a disinfection system and exposing the contaminated article within the enclosed chamber to a source of a disinfecting vapor including nitric acid for an exposure time sufficient to disinfect the contaminated article by achieving a reduction in colony forming units of the disinfected contaminated article relative to the contaminated article. Exposing the contaminated article within the enclosed chamber to the source of the disinfecting vapor may include alternately exposing the contaminated article to the disinfecting vapor for a first time interval, and exposing the contaminated article to a water vapor for a second time interval.