Although ozone is widely used in industry and commerce the ozone layer, a portion of the stratosphere, is beneficial: it prevents damaging ultraviolet light from reaching the Earth's surface. This same oxidizing property, however, causes ozone to damage mucous and respiratory tissues, so for safety and comfort purposes, we always recommend using the dryer and sterilizer in a space with adequate ventilation, and stay away from it while it is disinfecting objects with ozone.