I have a rather cheap USB toy plasma ball. Now I read, that plasma balls can be an eye hazard, if the glass does not filter the emitted UV light. I do not find many sources on how dangerous this actually might be, but I suspect that such a cheap toy will probably have cheap glass which does not filter much of the UV spectrum.

Should I be worried, that a cheap plasma ball may be an eye hazard?

  • 1
    $\begingroup$ Great question, though possibly on the edge between Physics SE and Medical Sciences SE $\endgroup$ – TheEnvironmentalist Feb 7 at 20:22
  • $\begingroup$ Thank you. I guess the most important thing is to learn, how much UV it may emit. First the claim that UV resitant glass is needed comes from german Wikipedia without a citation and I did not find a sound source for it, yet. Second, I would like to know how likely it is that a cheap glass ball will already filter the UV levels which are emitted. The medical science part would be about the safe limit for the human eye, but I think it is not the correct site for the question what may be emitted by the ball. $\endgroup$ – allo Feb 7 at 20:30
  • $\begingroup$ Cheap glass is a good filter. $\endgroup$ – Alchimista Feb 8 at 9:05

Cheap glass absorbs UV. If one wants to make a UV lamp one needs more expensive materials like for example quartz glass (fused silica).

And the light levels are low anyway. Such plasma spheres only look good in dark surroundings. Light levels and UV levels are much lower than outside in sun light.

  • $\begingroup$ Should I check if the glass has a minimal thickness or can I just assume that any glass they may have used is fine? $\endgroup$ – allo Feb 7 at 20:40
  • 2
    $\begingroup$ @alo Any thickness should be fine. $\endgroup$ – Pieter Feb 7 at 20:41

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.