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My kids and I were playing with a small plasma globe like this:

Plasma globe

After touching it we all noted a faint smell like that created by other high voltage static discharges, which I always understood to be the smell of ozone.

So I guess this is actually two questions:

  1. Is the smell associated with static electric discharge in fact ozone?
  2. Do plasma globes like this create ozone?

(Presumably if the answer is "yes" then it would not be a good idea to leave one of these operating for an extended period in a closed space like a child's bedroom!)

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    $\begingroup$ I think the answer to this one is already summarized in Wikipedia's article on ionisers. Whether the ozone and the products of oxidation are dangerous, is still controversial; but I think there is just not enough ozone produced by the properly working plasma globe to be a real problem. $\endgroup$
    – andselisk
    Jan 17 '18 at 18:02
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    $\begingroup$ @andselisk – Yes, given the controversy, we don't need to get into my parenthetical health comment. $\endgroup$
    – feetwet
    Jan 17 '18 at 18:16
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    $\begingroup$ Small amounts of nitrogen oxides may also be generated, and they also have distinctive odors. However, ESD created by pulling fabric from a clothes dryer or peeling adhesive tape also makes a tiny bit of these reactive chemicals, and I don't know of any ill effects. $\endgroup$ Jan 17 '18 at 18:53
  • $\begingroup$ Ozone has a pretty distinct smell (although some people say it smells like chlorine gas, which obviously couldn't be produced by the plasma globe) and humans have a good memory for smell. So if you've smelled ozone before and think that's what your globe smells like, then you've got a pretty good positive test for ozone production. The threshold for ozone to be detected by smell is about 100 ppb, which is about the same as the threshold for ozone to cause damage to the respiratory system, so I wouldn't dismiss safety issues out of hand (although this isn't the place to discuss such things). $\endgroup$
    – airhuff
    Jan 17 '18 at 21:49
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Plasma globes do indeed produce small quantities of ozone when they are touched. This is because the high-voltage within the globe is at very high frequency and this can drive high kinetic-energy electrons through the glass to produce ozone generating micro-discharges at your fingertips. Nox generation is highly unlikely at the low energies used.

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