A process and a system using a disinfecting atmosphere for deactivating Bacillus bacteria and its spores, such as Bacillus anthracis (anthrax) and C Botulinum and its spores, commonly proposed as bioterrorism threats, are described. Said disinfecting atmosphere includes ozone at a concentration of 2-350 ppm by weight and hydrogen peroxide at an amount of 0.2-10 weight percent at a relative humidity of at least 60%.
