It was evalued the activity of gaseous, aqueous ozone in environment with high humidity to decontaminate catering equipment intentionally contaminated with environmental, fecal and potential pathogen microorganisms. The data showed a wide variability in results due to single or multiple causes. The intensity of treatment, the type of the microorganism, its presence as cell or spore, the method of "wet", "dry" and "plate" or the method in high humid atmosphere seem to be the main causes of this variability. In any case, the type of treatment and in particular the use of 2 or 4 ppm of ozone, have allowed to obtain, regardless of the microorganism, decontamination between 1 and 5 log reduction. Ozone is a valid alternative to chemical disinfectants.
