The ozone generated by the machine dissipates within 2 hours. I would make sure to use the ozone generator in a room/place where no one would enter for at least 2 hours after the machine turns off.
There is no need for such cautions since the ozone is contained in the bag I sewed. After running the machine for 24 hours I walked around the bag and sniffes and could not detect any ozone smell escaping the bag. Then I opened the bag and could smell the ozone very well but as mentioned the smell of ozone goes away very quickly and all other odors are gone leaving my gear scent free.