The permissible exposure limit for ozone is 0.1 PPM.
The IDLH (Immediately Dangerous to Life and Health) level for ozone is five ppm.
That's half of chlorine which is 10 ppm.
Most major brand air purifiers put out a very minimal amount; the ionization is beneficial because it makes the really tiny (and thus most hazardous) particles clump and fall/stick to surfaces faster.
It's the offbrand units that generate lots of ozone to make people think they're "doing something", and commercial ozone generators for car/room deodorizing, that you have to be extremely careful with. Those need to be set up and then the room left for hours for the ozone to react with stuff, and then ventilated thoroughly.
I don't trust most air purifier manufacturers. They totally would add a fancy-sounding feature which sounds good, even if it has negligible effect, or even negative effect. Case in point: they're still pushing ultrasonic humidifiers.
The tiniest particles aren't necessarily the most dangerous, so even if "clumping" worked as advertised, it wouldn't necessarily be good. Air filters are worst at filtering particles at about 0.3 microns, they're better at filtering smaller ones (I understand it has something to do with brownian motion). I wouldn't be at all surprised if a similar thing affected our biological "filters". Either way, if you have a filter, you don't need UV to clean air. Just push more air through it if you need cleaner air faster.
Yes and it wasn't sarcastic, both things (what you said and what they said) are simply true. I think their point was not to be alarmist like you should stop breathing, but simply that everyone knows the one thing and most people don't know the other thing, and it gives scale or context to the "you don't want extra ozone".
The other posters here are right. I just wanted to point out the odd beauty in the fact that the fuel that makes our biology possible is also one of the things that is killing us. If you get a chance, read up a little bit on redox reactions and oxidative stress and take a moment to appreciate that.
We harness the energy of oxygen. It's the fuel that powers us. But it's also so reactive that it's constantly damaging our DNA and intracellular components. Over time it ages us, causes cancer (daily - our biology fights back!), and will ultimately be part of what wears us down and kills us.
Look at oxygen as a very reactive and energy abundant fuel. And then consider its abundance in our atmosphere. And then how it powers human locomotion, human biochemistry. And how it creates free radicals and chain reactions that strip our DNA and mutate base pairs. And all the tens of thousands - no, countless more - interactions and reactions it's having all throughout our bodies at all times. And how our biology evolved compensation measures to keep those deleterious effects at bay for as long as possible - as long as necessary - to enable reproduction.
Our biology is utterly awe-inspiring when you think about it. An incredible machine molded by our gravity well and abundantly available energy. Not just fighting against entropy, but actively sailing its turbulent energy gradients.
Absolutely. I vent the house after running UV lamps using a 4400 CFM air mover. I leave the house and run errands. I have 3 of these [1]
They have a remote control that "arms" them and it starts beeping slow, the faster, then much faster then activates. It kills insects be destroying their lungs and entirely destroys mold, bacteria and even damages viral material. Hospitals run the same lamps in wings that they close down for sanitation. The entire area has to be 100% vented.
I worked for a germaphobe, and he put one of these ozone-injecting air purifiers in our tiny office. Every morning I would walk in and it felt like I was walking into a thunderstorm from the smell. No gunpowder, just thick ozone
I imagine the UV energy itself weathers surfaces like the sun does, but at different scales. It's probably not enough to matter from the lamps.
"Hot car smell" is plastics in the car releasing volatile gas from the heat and sunlight, and surfaces in general fade, peel and crack from sun exposure over time. Thought maybe something like that would happen with different exposed materials to the lamps.
Diatomic oxygen is already a highly reactive fuel that is killing us and giving us cancer every single day. The ozone species is even more oxidative.
Oxygen is how we move about the energy gradient, but it's also killing us. Ozone is worse.
"Air purifiers" with ionization are probably not worth the squeeze.