Why not put your samples in a glass case using UV blocking Glass?

Vern

Darren Gibbs wrote:
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> On Monday, September 22, 2003, at 11:13 PM, Jinx wrote:
> > none make explicit warnings about LEDs, particularly any
> > requiring warning labels, eg
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> The part we're using now is from ETG... the ETG-5UV405-30.  At the
> bottom of their data sheet they say:
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> CAUTION: EMITS ULTRAVIOLET RADIATION!!
> =B7  This device radiates intense ultraviolet (UV) light when operated.
> =B7  Exposure to UV radiation can be harmful to your health. Protect yo=
ur
> eyes and skin during operation.
> =B7  Do not look directly at the device during operation. Exposure to U=
V
> light, even for a brief period, can damage your eyes.
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> However, I emailed ETG asking them about the danger and they won't be
> specific.  They just say "probably not a good idea to look at the light
> too long".
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> >  Your artwork will be visible because the UV has been
> > transformed into visible wavelengths, but it's hard to say what level
> > of UV reflects unaltered - I'm guessing not much.
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> In this case, the LEDs are shining up through large quartz crystals,
> which apparently transmit UV easily.  So we're not looking directly at
> the LEDs, but the light is still quite bright as it's transmitted up
> through the crystals.  Even though these are called "UV" LEDs and have
> a narrow band (400-410nm) the light is directly visible as violet light.
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> > Compared to an
> > arc welder (which is quite easy to get flash burns from) or a
> > germicidal
> > lamp, I'd have thought LEDs wouldn't be a concern in a setting such
> > as your.
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> Me too...
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> > But I'm not a doctor or FDA researcher
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> For anyone interested, here's what the interesting part of the FDA
> regulations on UV lamps say:
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>      (ii) The spectral transmittance to the eye of the protective eyewe=
ar
> required by paragraph (c)(4)(i) of this section shall not exceed a valu=
e
> of 0.001 over the wavelength range of greater than 200 nanometers 320
> nanometers and an value of 0.01 over the wavelength range of greater
> than 320 nanometers through 400 nanometers, and shall be sufficient ove=
r
> the wavelength greater than 400 nanometers to enable the user to see
> clearly enough to reset the timer.
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> Which _implies_ that >400nm is basically safe.  Since these LEDs peak
> at 405nm, but produce 400-410nm... I'm still not sure what to make of
> it all.
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> Thanks to everyone for the pointers and suggestions!  This list rocks!
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> darren
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