Safety Question involving 380nm or 400nm LED's

Hi everyone,

I have a safety question regarding eye health and 380nm or 400nm LED's.

I'm finishing up an arcade project that requires LED light from the inside the handle of a blue plastic TRON joystick. Originally in the '80's these glowed very nicely with an actual black light tube installed outside the handle.

I installed blue LED's inside the handle trying to get that cool effect. It's ok BUT- it would be so much better with the near UV LEDS like 380nm or 400nm.


My question is this- Is this safe for my kids' eyeballs? The LED's will be inside the handle and the light will pass thru the blue plastic of the handle and not be viewed directly. My hunch says that this is safe, but I wanted to know what you 'all thought about it?

A link to the actual plastic joystick is here: http://groovygamegear.com/webstore/index.php?main_page=product_info&products_id=319

Thanks in advance for any advice offered.


Chris

That's very long wavelength UVA light (the safest UV light). Bug zappers use shorter (more harmful) wavelengths than that, and I haven't heard of incidents with them. So I don't imagine it would be a problem, as long as the LEDs aren't extremely bright. They probably aren't bright, since UV LEDs aren't very efficient. I'd limit the power to something like 100mA, just to be safe.

BTW, plastic tends to filter out UV light. So it may just be better to stick with the blue LEDs if you're going to filter them anyway.

The most available black light tubes are 375nm and are widely used in night clubs and strip joints for ambiance light. None of the staff shows any problems and I've known a few people working in clubs that have black lights all over the place. Well, honestly they seem to be used less and less, but I believe that's mainly because the 80's are over and we have other light color and brightness options. On top of that, plastic absorbs a whole lot of UV (likely more than 80% and more as I have measured greater than 90% drops through thin plastic lenses with 365nm UV lights). I don't believe there is a reason to worry.