Begging your pardon, but this is simply not true. A negative ion is _any_
atom with an extra electron attached to it (or two, or however many you
can get to stick.) Ozone is a specific compound, chemical formula O3.
Simply a molecule comprising three oxygen atoms.

Mind you, ozone is a _by-product_ whenever there is ion generation going
on, but the idea that "negative ions" and "ozone" are the same is terribly,
deeply, mistaken. My intent here is not to hurt your feelings, but I guess
I'd have to say I'm on a crusade to prevent this kind of misinformation
from being promulgated as if it were fact.

Yes, you are correct, literally.

But, where you find negative ions, you will find ozone in the same
air. And, any voltage that is instrumental in producing negative ions
will also produce ozone.

Literally, they are not the same, you are absolutely correct. But,
with respect to the air purifiers...a negative ion generator must also
produce ozone.

M