My uncle has ozone generators in his home. One of them is industrial strength and he only runs it when he is leaving his house for awhile. Does ozone produce by products? I vaguely recall hospitals used ozone to clean n95 masks.
Cleaning air is simple; you don't need to look to obscure Ozone/UV devices.
For gasses/VOCs, you need a carbon filter. The larger the filter and more air that moves past it, the better. You can grab industrial ones used in greenhouses for ~$150, some brands (LAYOND on Amazon) have cases that make them look alright and make them quiet.
For particulate (dust), a carbon filter works OK but a HEPA filter is better. Get a name brand one (Honeywell) so you're not getting ripped off.
None of that will replace the lack of oxygen, though-so open a window.
I would think that it would be really hard to make any kind of dent in how much oxygen is in the room... wouldn't, by the time you get there, you have long long since died of carbon dioxide poisoning?
Here’s the basic levels of CO2 that are acceptable in a room. I know I get drowsy in rooms without good airflow when in meetings at the office.
https://www.engineeringtoolbox.com/amp/co2-comfort-level-d_1...
Ventilation is critical, lest you get other issues such as mould which is a whole other set of problems in itself.
IKEA do some very good value devices. The Fornuftigs are nice, but quite weak. The Starkvind smart purifiers are better. They’re explicitly not HEPA and aim for less dense media / higher cycles, and they produce generally similar results at lower costs.
(There are some poorly informed reviews online that give a bad review because they’re not marketed as true HEPA filters, but this misses the point of cleaning the air you breathe rather than the air inside the unit. There was a post that corrected these reviews on HN some time back, will try to dig out and update).
Here is one anecdotal example: https://www.reddit.com/r/homeowners/comments/d2rjsb/ozone_ge...
N95 masks actually seem like one of the few use cases that make sense, as their composition is well known and they can be easily enclosed. Even when ozone generators work as expected, they can take months to remove odors from spaces.
At the end I decided against the ozone generator for my home and went instead for an air purifier with filter.
UV, Ozone and vaporized hydrogen peroxide are all used to some extent. None of them in ways I'd recommend for the home.