# UV output from HID lights



## Apollo Cree (Apr 1, 2010)

The issue of UV output from HID lights has come up several times, along with a lot of misinformed speculation. I've decided to do a little testing. 

At the moment, all I have for UV testing is some old photogray prescription eyeglasses. 

Some problems with this are: 

1) UV sensitivity of photogray lenses is not necessarily an accurate representation of the UV damage sensitivity of human skin or human eye lenses, corneas, or retinas. 

2) The sensitivity of the photogray lenses varies with temperature. More later. 

3) I don't have a good way to quantify the response of the lenses, other than "high, low, none, etc." I'm working on taking some photos, but the results are unsatisfactory at the moment. I may need to make a more elaborate photo setup.


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## Apollo Cree (Apr 1, 2010)

*Initial tests*

I'm using a Stanley 0109 HID lamp. 

I let it warm up for at least 1 minute before testing. 

Unless otherwise stated, all tests are done with the lamp as close as possible to the glasses. 

1) Stanley 0109 HID, 10 seconds - Several times more response than full sunlight. 

2) Stanley 0109 HID, 10 seconds through a plate of ordinary window glass. - Maybe 50% of response not through glass. 

3) iTP A1 EOS 200 Lumen LED. - Very minor response, maybe 5% of the response of sunlight. This is somewhat interesting because I presume there's almost no UV at all, merely deep blue light. 

4) Through a pair of LaRue gray polarized fitover sunglasses for 1 minute - Almost no response. These are fairly dark plastic polarized sunglasses. The lens is a thin plastic film. This is the type of sunglasses that cataract patients tend to wear, fits over prescription glasses. 

5) Stanley HID 0109 1 minute exposure. Less response than the 10 second exposure. I will experiment with this further, but I'm pretty sure that the reason is that the glasses became hot. This particular type of photochromic lens seems to not darken as much when it's hot as it does when it's cool. 

Quick conclusions:

The HID lamp DOES put out UV light. 

Ordinary window glass does not filter out all of the UV light. 

I can't assess the health risks of UV light from the lamp, but there is probably some legitimate concern. Personally, I'm not going to worry about it in any reasonable spotlight type use. I'm not going to do anything stupid like point it at my skin or eyes at close range for long periods of time. I would NOT feel safe using it in an application where I'm exposed to it at close range for hours at a time, such as using it as room lighting or even for lighting some kind of close up project for half an hour or so. 

It's a spotlight. Use it for shining for short periods of time at somewhat distant objects.


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## bshanahan14rulz (Apr 2, 2010)

Does your car have HIDs? Car HIDs use 35W capsules as well, but are made by reputed manufacturers (Philips, Osram, etc.). It would be interesting to see a direct comparison between a bare china bulb like what is in your torches (or behind the glass lens, since it IS shooting 23,000V through there)
vs. a Philips or Osram D2S bulb.

Also, car headlamps get another level of protection. First, there is the Quartz + UV-stop glass on the outside of the capsule. Then, there is the thick, glass, aspheric lens of the projector, the norm for controlling HID output. Lastly, if any UV makes it out of the projector, it still has to make it through the anti-UV clear-coat on the outer polycarb lens.

I like that you are testing this, thank you for taking the time. I ought to see if I know anybody with these types of sunglasses. I have halogen headlamps, but HID optics and light source. Would be curious to see if I have any UV leakage...


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## Apollo Cree (Apr 2, 2010)

Sorry, no HID on my vehicle or any friends I can think of. If I find someone with a set of HID headlamps, I'll try the experiment.


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## Apollo Cree (Apr 9, 2010)

This is about 15 seconds with the Stanley HID 0109 point blank. The lens looks darker than it really is, since the light passes through the lens twice. 

I wasn't able to get any good shots indicating different responses of different exposures. The glasses just aren't a good measurement device.


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## harro (Oct 12, 2012)

*HID and UV*

Hi;
I was hoping someone could enlighten me on the following point.
Do HID bulbs give off uv or any other sort of irradiation?
As much as i'd love to own a high quality HID light, prices in AUS. make that dream something difficult to achieve ( eg; Wolfeyes Croc $1,100.00 Microfire 3500 $595.00, both very nice in their own way!! ).
So i've got a couple of crappy Chinese things. A 2600 lumen torch with the three little led's in the battery pack, and a 3500 lumen spotlight ( which happens to output about as much light as the 2.6k torch !! ).
When using them as a candle, the torch is fine for the hour or so that it runs for ( ceiling bounce ), but the spotlight ( same ) gives me an absolute ripper headache and sore eyes. I know this is not their primary purpose, but has anyone else experienced this phenomenon?

Cheers


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## AnAppleSnail (Oct 12, 2012)

*Re: HID and UV*



harro said:


> Hi;
> 
> When using them as a candle, the torch is fine for the hour or so that it runs for ( ceiling bounce ), but the spotlight ( same ) gives me an absolute ripper headache and sore eyes. I know this is not their primary purpose, but has anyone else experienced this phenomenon?
> 
> Cheers



That is UV overexposure, especially the sore eyes. Feels like grit? Get some filter glass on it, and don't use it indoors.


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## harro (Oct 19, 2012)

*Re: HID and UV*

I think you're right, just dont use it inside. It was a bit of an experiment in the first place. Interesting that one crappy HID doesnt do it where the other does. I'll keep saving for that Polarion/ Wolfeyes/ Microfire.


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## bshanahan14rulz (Oct 25, 2012)

*Re: HID and UV*

The cylindrical envelope around the arc chamber is supposed to be made of UV stop glass. Maybe some glass is better than others.


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## alpg88 (Oct 25, 2012)

bshanahan14rulz said:


> Also, car headlamps get another level of protection. First, there is the Quartz + UV-stop glass on the outside of the capsule. Then, there is the thick, glass, aspheric lens of the projector, the norm for controlling HID output. Lastly, if any UV makes it out of the projector, it still has to make it through the anti-UV clear-coat on the outer polycarb lens.
> ..


polycarbonate itself will not pass anything lower than 390nm or so. i have learned it the hard way, and uv coating is made so the lens wont get yellow from sun's uv. hid car light is bad example, or reference.


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## ma_sha1 (Oct 25, 2012)

A good friend of mine was doing 400W HID mods & shined light into his own eyes by accident.
He suffered perminant damage & quit modding.

I wear PC eye glasses for HID mods & PC Face mask for short arc mods


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## bxstylez (Oct 28, 2012)

ma_sha1 said:


> A good friend of mine was doing 400W HID mods & shined light into his own eyes by accident.
> He suffered perminant damage & quit modding.
> 
> I wear PC eye glasses for HID mods & PC Face mask for short arc mods





wow .... what kind of permanent damage if you dont mind me asking?
blindness in one eye?


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## ma_sha1 (Oct 29, 2012)

Eye hurts & blurry vision, it lasted a few weeks & eventually he went to the Dr.
Dr. doesn't think it's the light, but I don't the Dr. run into a similar cases to know what zapping by 400W hid would do.


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## AnAppleSnail (Oct 29, 2012)

Tell the doctor that your friend was exposed to a high-output arc lamp with high UV output. This will help clue the guy in to what treatment can alleviate severe UV exposure.


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## storkus (Nov 2, 2012)

Hi guys, I thought I had an account here from back when I bought my Bacchus/Stanley HID0109, but I guess not...

Anyway, being rather interested in fluorescent and radioactive minerals (and items in general), I know a few things on this subject, and Wikipedia knows a lot more.

First of all, a HID bulb is made of quartz, which will pass UV of all wavelengths down to UVC aka shortwave UV.

Wikipedia articles:

http://en.wikipedia.org/wiki/High-intensity_discharge_lamp
http://en.wikipedia.org/wiki/Fused_quartz and
http://en.wikipedia.org/wiki/Ultraviolet
http://en.wikipedia.org/wiki/Mercury-vapor_lamp

In other words, a mercury discharge emits lots of UVC at 257 nm, which for us fluorescent enthusiasts is in the shortwave region; you MUST use quartz at this wavelength/frequency. Below this is vacuum UV, which mercury emits about 10% of at 185 nm, but gets absorbed by air, creating ozone; in theory, this shouldn't reach you, the modder. Above this is UVB and UVA aka "blacklight" aka "longwave UV" at around 350-390 nm (UV LED's are typical 395 nm). This shouldn't hurt you permanently, but anyone who's stared into a blacklight-blue fluorescent bulb knows it hurts your eyes after a while.

The point here is that ordinary glass will block the dangerous UVC, but the longer wavelengths will definitely get through: this is the big reason why street light HID bulbs don't come "naked", besides environmental protection for the tube itself. In a HID car light or spotlight, the glass does the same job; it may be Pyrex or ordinary soda glass, but it'll still block the shortwave UV.
If you want the longwave blocked, you need probably need something like sunglasses or arc-welder goggles (though those are designed for IR as well).

Now here's some links from the opposite end of the spectrum:

http://www.uvp.com/pdf/a112.pdf A discussion of solarization--important for long-term use in HID lights?
http://www.uvsystems.com/articles/Life_SW_Filters_UV_Depreciation_Lamps.pdf <-Ditto from a different company
http://www.uvp.com/pdf/T-001.pdf An OLD app note!
http://uvsystems.com/faq_general.php#FAQB19 This and the next question are directly pertinent to this discussion. Also see these 2 questions:
http://uvsystems.com/faq_general.php#FAQE1 (Covers blindness and ozone)

I know some of this may be OT, but overall I think it should be a big help; no doubt those of you who have been around longer probably have seen some or most of this.

Hope this helps!

Mike

P.S. Writing this from work at 4am with lots of interruptions, so excuse any weird formatting, etc


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## ma_sha1 (Nov 2, 2012)

storkus said:


> First of all, a HID bulb is made of quartz, which will pass UV of all wavelengths down to UVC aka shortwave UV. [1/Quote]
> 
> This is true as qurtz is need to withstand the high temp. in arc chamber.
> 
> ...


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## XeRay (Nov 2, 2012)

ma_sha1 said:


> However, The HID bulbs we use for flashlight comes from automotive industry, the bulbs all have an outer envelope made of non quartz glass, the purpose is to block the UV. So most UV emitted by the bulb is gone. Still, enough comes through cause damage if prolonged expose, but not short exposures.



Actually, Philips, GE and Osram (Sylvania) use "UV stop quartz" for the outer envelope.


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## boyakasha (Nov 9, 2014)

Hi everyone,

being in search of a reasonably powerful yet affordable UV light source for experimentation involving UV vision in aquatic animals I found this forum. After testing expensive "professional use" xenon arc lamps, like the abet 150 - which is a bit overpowered AND overpriced for my purposes I was thinking along the lines of HID bulbs. Now what I extracted from the info available online is that they 1. do in fact emit UV but 2. are mostly coated as to not let that UV radiation pass through.

However, I noticed several mentions of HID bulbs that are less well protected and may therefore really be what I am after.

So, seeing as a lot of people here seem to have tried various kinds of HID bulbs, and I was unable to come by information regarding the spectral emittance curve of HIDs for sale (contacted a few distributors...), maybe you could help me out here! 

Which ones do emit strongly in the UV? Where to get them? Any recommendation will save me tremendous amounts of time (and money) spent on speccing through the barrage of HID bulbs available out there...

Any help much appreciated!

Cheers,
Boya


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