UV protection required for UV LED's

[erdabyz]

This thread isn't about lasers, it's about LED's. I think this is a good forum to ask for them.

I'm gonna make a time fountain (maybe you've seen it in youtube) which requires 20 UV LED's. A big amount of UV light.

I wanna know what kind of protection is needed to block that. I know that LED's aren't very powerful  and that one doesn't make damage, but 20.....


¿Will sunglasses block 380-410nm UV (wavelenghs range of a common UV LED)?

I have ski sunglasses for snow, but they have kinda orange lenses. They must be good quality because they are from a well known brand and were expensive when I bought them. But I don't know if they will block that range.

I've also read that polycarbonate blocks UV with a very high OD. I have polycarbonate safety goggles for drilling and cutting with machines.They have clear lenses.
Will they work?

I want something that blocks UV but lets most of the other light pass, because I wanna see the water fluoresce and the "stopping time" effect of the  time fountain.

 

[FrothyChimp]

Sunglasses will work fine with LED's as long as your glasses provide UV protection.

To everyone reading this: NOTICE, these are not laser diodes. They do not produce coherent and monochromatic light and therefore UV blocking sunglasses will work fine. Lasers require laser protective eyewear designed specifically to attenuate the very high incident power associated with phased light sources.

 

[Benm]

Well, i'd test any pair of sunglasses before using it as protection for these wavelengths... your typical "uv" led emits light around 400 nm, just a little below or above depending on quality.

Sunglasses with "uv protection" should start to block light at 400 and shorter, so its all just on the edge.

On the positive side, the emission from such leds isnt actually very dangerous, as long as you dont stare directly into them. It's not even the uv that poses the danger, but the badly visible wavelength in combination with the output power.

 

[erdabyz]

My sunglasses provide a very high UV protection. Snow reflects a lot of light and that''s why high UV protections are required. They are UV 400 what measn that they block all UVA and UVB. But UVA has 400-320 nm range, and UV LED's are supposed to emit between 380 and 410nm. I don't think my LED's will emit all above 400nm.

Is there any kind of sunglasses that block above 400nm?


Ahm, other thing. I've seen blacklight tubes at discos (purple colored), and they are above 15W, and nobody there uses protection against that. I also have a PCB insolator that has 3x8W actinic tubes (white colored), and nobody told me to use sunglasses when using them. This tubes are also used for lizards and similar pets, to provide them "sunlight". This kind of tubes emit a lot of UV. But with LED's everybody says that protection is required. Why?

 

[Benm]

But with LED's everybody says that protection is required. Why?

Disclaimers?

The typical, affordable, 5mm UV led is not dangerous, unless you would put it right up to your eye and stare into it - for a long period of time. Something like the time fountain is perfectly safe to build and put up as a display/conversation piece.

 

[suiraM]

For UV LEDs, I have had great success with yellow polycarbonate lenses intended for certain kinds of welding work. I can't recall the IE166 code off the top of my head, but make sure you check that. They're great substitutes for sunglasses in daylight, too. A lot less fatigue to the eyes.

Regarding UV LEDs not being dangerous, that's BS, as far as I know.

Granted, they will not generally cause short term damage, unlike a UV laser or a high power UV lamp, but they will raise the oxidative stress level in your cells, and they are in the wavelength range suspected of contributing to the development of age-related macular degeneration. Particularly if you've got nordic ancestry. Thus, I would think erring on the side of caution is a good idea.

It's not just about keeping your vision tomorrow, but keeping it for life.

 

[Cyparagon]

Oh come on, it's not like 401nm is safe and 399nm will kill you within a few hours of exposure. All the UV LEDs I've seen are 395nm (+/-5) which isn't exactly ionizing.

 

[Razako]

You're scared of 5mm uv LEDs like those found in those invisible ink pens for kids? Just don't stare right into them for hours a day and you'll be fine.