UV light how dangerours

I had been shown a homemade LED devise described as violet light. but looking into the details the wavelength is 405nm. I have found two LED's from RS components 405 and 410 both described as UV both with danger signs on them. what is the truth of this and what are the dangers of UV light?

 

The question is How much Uv light and for how long .

UV light causes eye damage and skin cancer from what I have read ,
but a few led's won't be of harm.

 

Reflected light from a UV LED is not going to be a problem, just don't look directly at them.

Edited: diffuse reflection that is, not mirror like reflection.

Bob

 

Some people can see light at a wavelength of 390nm, some cannot see light at less than 410nm. This is why the company calls it purple light, since a lot of people can see the light. Some places will call it UV since it is very close to the UV region.

Fortunately, light at this wavelength will have little effect at damaging you since there is not enough energy in the photon to damage chemical compounds. Although it might lead to blindness if you look directly at it for prolong periods.

 

Time for an irrelevant story. I once used a lab procedure for separating the morphine alkaloids (!!) using thin layer chromatography, which employs a thin powder layer on glass plates. The alkaloids could be separated and then recovered by scraping the powder off the glass. We used UV light to visualize them. I knew the light was "dangerous" but I was careful not to look at the lamp.

It's embarrassing to admit that it didn't dawn on me that the reflected light was dangerous too.

Well, after spending the day scraping plates under UV, I had to go to the doctor for sunburned eyes. Hurt like hello, and scared the crappie out of me. That was 30 years ago and my eyes are fine as far I know, but I can tell you I've been very careful ever since.

Nothing like a near miss to make you appreciate safety.

 

I have been using the machine on and off for a few years. I would not look directly into the light straight on but often from the side or an angle looking at the LED'S, but probably not for more than 30 seconds.
can this be of any problem?
from what you say 405nm may be out side of the UV range and not harmful.
the warnings on this document was what had initially worried me. -
http://docs-europe.electrocomponents.com/webdocs/0e77/0900766b80e77d27.pdf

 

I can' t mess with uv light it makes me deathly ill ..
once i went into a tanner bed to help my ex out apply the lotion and i was subjected to 20 to 30 seconds of uv and my skin turned

red as a lobster and hurt like hell..

 

I would follow the warnings. You don't want to take a chance on eye damage from the UV. Here's a link discussing the exposure limits for various wavelengths of UV light and the damage that exposure can cause.

 

Because some people are more sensitive than others, the lawyers write the warning to frighten everyone. If you haven't noticed any problems, continue with what you are doing.

 

Surprisingly OSHA has no mandated/suggested exposure limits to UV light at all. (some mention of UV in the laser standards though)
However those are not UV. They are violet. "True" UV is under 400nm

They should be treated just like any other visible light source.. ie avoid directly looking as well as protection from reflected light.

 

thank you all for your thoughtful advise and information. i noticed on the link from crutschow - https://www.case.edu/ehs/Training/UV/UVsafety.pdf that UV light ended at 400nm I am always a bit wary of something that ends on a 0 or 00 but as LDC3 mentioned there will be little damaging potential at this wavelength as it is on the way out of UV to visible.

 

That's what NASA said about chunks of ice falling from the fuel tank during launch until it caused the loss of a shuttle.

Cataract formation is slow and can occur from long term accumulated exposure. If it were my eyes, I would take every precaution I could.

 

+1

That's pretty much the moral of the story I told earlier. I got lucky way back then.

Luck is not a strategy.

 

I won't be using the machine anymore.Thanks

 

Thank you thats very interesting. I also guess when dealing with DNA there are a lot of things and effects still to be found.

 

Does direct sunlight do that too?