Application of a novel decontamination process using gaseous ozone.

Environmental disinfection in a health care setting is an important aspect of infection control. Recently, there has been interest in the use of vapor- and gas-based treatments for decontamination of surfaces and rooms. We describe preliminary results for an ozone-based decontamination of surfaces seeded with a range of vegetative cells and spores of bacteria of clinical relevance. The efficacy of the approach for room sanitization was also assessed. The protocol included use of a quenching agent to rapidly reduce ozone concentrations to safe levels allowing treatment times of less than 1 h for the majority of organisms tested. Using bacteria seeded onto agar plates and solid surfaces, reductions in bacterial load of greater than 3 log values were recorded for a number of organisms including Escherichia coli and methicillin-resistant Staphylococcus aureus. Application of the process in a 30 m3 room showed similar reductions in viable counts for these organisms and for Clostridium difficile spores. We suggest that the potential of this ozone-quench approach should be further evaluated for disinfection or decontamination of healthcare environments.