Ceramic-based ozonizer for high-speed sterilization

A high-speed ozone sterilizing device has been developed, using a ceramic-based ozonizer of the high-frequency surface discharge type. The advantage of this ozonizer is that it can produce a high concentration of ozone despite its compact size. Oxygen is used to produce the standard ozone concentration of 20000 p.p.m. Even at this high concentration, complete sterilization for the reference bacteria (Bacillus subtilis) in a limited time (~3 to 5 min) is only possible in the case when adequate temperature and humidity are maintained in the ozonized oxygen gas (50°C and 80% relative humidity). The object to be sterilized is cleaned with a wet paper, to provide such humidity in the sterilizing chamber, which is kept at 50°C. For reference bacteria, this device produces the standard sterilizing effect of killing one million cells in three to five min. One run, including processing before and after sterilization, lasts 12 to 14 min as against ~30 min for the conventional method using an autoclave. The sterilizer, using a high concentration of ozone, has been used in the sterilization of a handpiece used in dental work for drilling teeth