Why you don't want an ozone air filter for litter box odor
As with room air filters, some manufacturers still promote ozone generators to deal with litter box odor. This link takes you to a good article on the dangers of ozone-based indoor air filtration whether for general household purposes, or specific to litter box air purification. Basically, it comes down to this: If the device generates enough ozone to be effective against odor (and they can be) that is too much for anyone to breathe. Conversely, if it generates so little that it is not harmful to breath it is not effective against odor.