It is NOx that comes out of a tailpipe or a smoke stack that reacts with VOCs, in the presence of sunlight, to create ground level ozone.
I have used ozone generators to make ozone gas to sterilize apple storage rooms. I have used the same generators to make ozone gas to kill bacteria in and on apple packing lines.
Ozone does a better job of sterilizing than any bactericide or chlorines could ever do and it is much safer since the MDS is far less demanding than any chemicals that can be used.