The "Caution: use in unoccupied space only" bothers me. As if unhealthy for you then unhealthy for plants as it takes away the oxygen? Carbon filter probably as cheap and works as good or better and don't have "health concerns".
Saw that on ebay the other day when i looking negative iron gens, did a bit of research and decided to steer clear of ozone gens, they say ozone isn't effective at safe levels for you or your pets. Carbon filter are super cheap