Photocopiers smell like ozone when they run if anyone’s forgotten the smell
Those are similar but sweeter. If I sterilize a room with UV it has a very distinct smell like nothing else aside from lightening and stun guns. I would UV the bathroom right now but then I have to vent the entire house and its 34F outside right now.
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.
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.
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.
I'm not normally one to miss the sarcastic or satirical posts, but this one seems oddly earnest.
I think they're referring to oxidative stress [1] caused by cellular respiration.
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.
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.
[1] - https://www.amazon.com/AeraLight-Whole-Surface-UV-Sanitizer/...
I imagine it will cause some material to off-gas aldehydes at the very least.
But I would worry about the effect on e.g. plastic seals. There are a lot of plastics that become brittle with ozone exposure, let alone UV exposure.
"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.
There are at least two types of UV-C light bulbs, as well as literal ozone generators that use ceramic platen and a fan. The type of UV-C bulb that is most common on Amazon and Ali is ~254 nanometers, and _does not_ produce Ozone. It does leave a smell, but it's more like an oldschool hospital antiseptic smell. probably the smell of the dead germs, yay.
Now 185nm is actually the correct size to turn O2 around the bulb into O3 (and more oxygens too, i once read, i think, kinda like cracking hydrocarbons to make longer chains or something).
UV-C bulbs (not base, which is an edison base) that can sterilize a room in 5-15 minutes are about 15-20 CM tall, with four crystal tubes that are connected together standing up on the base. image here [0]
you must run a fan over them if you want your money's worth. they get hot, the bases get hot, it makes the most sense in non-carpeted rooms to aim the crystal down and the base up, so that is real rough on them. that took me 2 bulbs to figure out.
If you can find a reputable place to get the box with ceramic and a fan that lasts more than 5 minutes, let me know, because that's closer to what i want for bedrooms and stuff.
The UV-C 185nm bulbs work great to make a car stop stinking, too! completely removes cigarette smells, if the car hasn't been smoked in for a while. run the A/C full blast and run the bulb for 15 minutes, open the windows for 5 minutes, roll em, sniff. Still smell? another 10 minutes, in the back seat, full A/C blasting. vent, sniff. Faint smell? replace the cabin air filter. Charge customer(?)
and i'm going to respond to your followup question to the GP as well: Covid. Obviously. They were telling us it would live on groceries and deliveries and that, so i put all deliveries in my laundry room and dosed em with UV-C for a minute. CDC or whatever studies said that 10-60 seconds was more than enough to kill sars-ncov-2.
I only use it for freshening cars, rooms, bathrooms, etc now.
WARNING: Do not be in the room with any UV-C light for more than a few seconds. Do not look at the bulb for literally any more than necessary to ensure it is on and safe. they make safety goggles that wrap your entire eye sockets to protect from UV, too. if you get a 185nm bulb, either completely ventilate the room with fresh air, or leave it sealed for 60 minutes then open it up for a few minutes, all the ozone reacts and goes away or something.
UV-C hurts your skin, yes, but it will make your eyeballs literally itch. so don't, don't don't look at it. they are not blacklights.
[0] https://m.media-amazon.com/images/I/71LgjON7J+L._AC_.jpg
This advice does not necessarily apply to far UVC (200-235 nm), which appears to be much safer for human skin and corneas than UVC outside this specific band. More research is needed before calling it "safe" but far UVC is almost certainly less hazardous than the rest of the UVC band.
Pay close attention to wavelength when purchasing UVC light sources.
I'll keep my eye out for more research on far-uvc and the possibility of getting a bulb to test.
oh by the way, i must have sent back 2 dozen "185nm" UVC bulbs from a dozen "manufacturers" because they didn't produce ozone, because they were fraudulent listings of 253.7nm bulbs - so this is why i was trying to steer people away from amazon and ali, as it's real easy to get the wrong type if you're looking for ozone. I've only managed to acquire 4 bulbs total in the last 5 years that produced ozone, and i burnt out two before someone said "put a fan on it, those bulbs are designed to be inside an air exchanger!"
https://pubmed.ncbi.nlm.nih.gov/38037431/
i'd never heard of ozone in far-uvc nor really far-uvc. For what it's worth, i don't think it matters. the "warning" median dose for Ozone is 1ppm, 100 times more than far-UVC puts out. the "danger" is 5ppm. For ref, Chlorine is 10ppm.
253.7nm does not produce any (or less than 1ppb, which i consider the same thing for my body), and 185nm produces a lot. My warning is specifically to people who want to or need to use the lamps and also think that google isn't very good.
supposition: we don't have the material or material science that is transparent enough between 185 and 254 nanometers to induce more ozone levels than 185nm does.
Humans are built to withstand a constant assault on their immune systems. We couldn't have survived if we didn't.
Its a bit naieve to claim that cleaning one's home will result in an extinction of enough microbes so as to be threatening to our immune system.
https://en.wikipedia.org/wiki/History_of_polio
> [...] Better hygiene meant that infants and young children had fewer opportunities to encounter and develop immunity to polio. Exposure to poliovirus was therefore delayed until late childhood or adult life, when it was more likely to take the paralytic form.[22]
The anti vaccine position makes a very strong claim, namely that vaccines will cause complications that are strong enough to justify not vaccinating children, which is obviously false since a lot of the diseases that are vaccinated against have actually killed children and the vaccines have dropped child mortality significantly and the complications that are supposed to be avoided by refraining from vaccines tend to be both rare and non life threatening.
You can't make the same argument with the hygiene hypothesis, because the claim is really weak. Nobody is saying that extreme hygiene will kill you. The argument is along the lines of "lack of exposure to environmental microbes, viruses or allergens may lead to an unprepared immune system that hasn't developed a wide variety of anti bodies or is more likely to develop allergies or autoimmune problems".
I'm not sure how I would be able to argue against this claim since it only takes one microbe, virus or allergen to make it true.
The context here isn't hand washing vs not hand washing, it's aggressive ozone + UV sterilisation vs regular hygiene.
Not to mention that the hygiene hypothesis has an even weaker version still, namely the "old friends hypothesis". It seems pretty weird to equivocate this to being against vaccines.
'Anti-vaccine claims' suggests a taking of sides on that knee-jerk division into those who claim without evidence that almost or even all vaccines are deadly and on the other hand, those who are frankly contemptuous of any claim that a particular vaccine (evident particularly with the vaccines developed in response to the Covid outbreak) might be dangerous for certain people. Both extreme views have been on view recently and are indefensible.
The major issue here is the difficult task of identifying people likely to react badly to any specific vaccine.
Meanwhile 'Congress and Institute of Medicine Confirm Government Licensed and Recommended Vaccines Can Cause Injury and Death' and 'The 1986 National Childhood Vaccine Act was the first U.S. law to officially acknowledge that childhood vaccines licensed and recommended by the federal government, which are routinely mandated for school attendance by state governments, can and do injure and kill a minority of children.'