LED and UV concerns

[Marc]

Hey All,

I'm trying to find some information on how safe these UV LEDs are on my fixture? Ive got a little one and she loves looking into the tank. Shes always attended to when close to the tank because we dont want her looking directly into the lights. Are there any concerns with the UV LEDs? My fixture is full spectrum I believe with UV.

Thanks!

 

[rygh]

You need to be more specific on the LED emitter.
A standard cool-white is often called full-spectrum, and would not be an issue.
But a fixture with multiple LED types, that has a UV or near-UV specifically, is a bit of a concern.

Can you directly see the LED emitter itself?
If it is through the water, not much of a concern.

I doubt she directly looks at the lights much. Painful.

Perhaps consider a hood. Keeps the little fingers and toys out also. Yes - that is a problem!

They also sell tempered glass that blocks UV. Look in the metal halide DIY areas.

 

[sfsuphysics]

Most "UV" LEDs are not true ultraviolet and often is in the 410-430nm range, and is perfectly safe.

If you in fact have true UV bulbs, chances are they're just barely into the UV range in the 380-400 nm range and they're not dangerous at all either. A fluorescent tube black light is going to be more damaging.

Now if she can stare directly at a LED there could be some temporary vision issues, akin to staring into a bright light and seeing spots, however our natural defense for this is that we feel pain and squint or look away the problem with those "UV" bulbs is they don't look very bright to us as a result we don't necessarily feel pain. Not to say they will cause damage, you'll really have to try hard to damage your eyes with LED light.

If you're really that worried you could probably fabricate some sort of shield for the front of the tank, maybe something out of black acrylic or something.

 

[Marc]

You need to be more specific on the LED emitter.
A standard cool-white is often called full-spectrum, and would not be an issue.
But a fixture with multiple LED types, that has a UV or near-UV specifically, is a bit of a concern.

Can you directly see the LED emitter itself?
If it is through the water, not much of a concern.

I doubt she directly looks at the lights much. Painful.

Perhaps consider a hood. Keeps the little fingers and toys out also. Yes - that is a problem!

They also sell tempered glass that blocks UV. Look in the metal halide DIY areas.

Most "UV" LEDs are not true ultraviolet and often is in the 410-430nm range, and is perfectly safe.

If you in fact have true UV bulbs, chances are they're just barely into the UV range in the 380-400 nm range and they're not dangerous at all either. A fluorescent tube black light is going to be more damaging.

Now if she can stare directly at a LED there could be some temporary vision issues, akin to staring into a bright light and seeing spots, however our natural defense for this is that we feel pain and squint or look away the problem with those "UV" bulbs is they don't look very bright to us as a result we don't necessarily feel pain. Not to say they will cause damage, you'll really have to try hard to damage your eyes with LED light.

If you're really that worried you could probably fabricate some sort of shield for the front of the tank, maybe something out of black acrylic or something.

Mike and Mark,

Thanks for your replies. Obviously our kids come first so if there is something that could potentially harm them, Ive got to do something about it.

Definitely possible to look directly into the emitters especially at her height. She knows not to look at them directly and in fact i saw her do it once, she quickly looked away.

One thing to add, since you brought up tempered glass - The fixture itself has glass in front of the LEDs but not sure if its tempered. I can take closer pics tonight when I get home.

The tank is in our office room , so the little one is only in there when someone else is in there as well. I could possible hang a drape over the fixture when shes in the room.

Here is the fixture over the tank

 

[rygh]

Even regular glass blocks a lot of UV, so if it has a glass plate, that helps a lot.
Interestingly, I see light from all of the lenses. That is a sign that you have no dedicated near-UV LEDs.
And honestly, I doubt you would from any non-DIY fixture anyway.

So my opinion : UV is not a concern.
But spending a lot of time right in front is not particularly good for the eyes.

PS: Since you are being concerned. One danger to kids is the tank toppling over.
They tend to reach and climb, and can pull things over.
A small-ish narrow tank carpeting can be an issue.

 

[Marc]

PS: Since you are being concerned. One danger to kids is the tank toppling over.
They tend to reach and climb, and can pull things over.
A small-ish narrow tank carpeting can be an issue.

You read my mind! Ive already got a bracket I'm going to hook up to the stand and wall.

 

[Marc]

Speaking of the devil!

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[HiFidelity]

>400nm is safe to human eyes, the farther down from 400nm the number gets the worse the light is for the human eye, in reef lighting it's rare to find LEDs that are under 400nm and even when you do find one it's like 390-395

 

[Marc]

Thanks Fidel, I feel more comfortable with my kid around the tank.

I took a picture of all the LEDs on for what it's worth. I was guessing the purple ones where uv. It's a lot brighter in the picture than in real life. If those were true UV, would they not be visible?

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[sfsuphysics]

If those were true UV, would they not be visible?

Yes/no.

Yes in that true ultraviolet light we can not see, no in that "true UV" might not have such a tight spectral bandwidth (the range of wavelengths it puts out) that it's ONLY UV.

Think of the old incandescent bulbs we used for lighting back in the day (or halogens if you use them) only like 5% of the light is actually visible, 95% of that light is infrared light which we can't see but if we get near the bulb we can feel it. Now LEDs tend to have a small range of wavelength it puts out, so if you can see it there's a good chance it's almost all in the visible spectrum, there might be some in the UV however it'll be such long UV wavelengths that it's practically visible light as far as hazard (which is to say none)