[UVC SAFETY WARNING] FDA warns not to use certain UVC wands

[dabateman]

Well this may not be a surprise to most here. But UVC is dangerous and certain "cleaning" devices are outputting enough UVC to burn your skin and eyes.

https://www.fda.gov/medical-devices/do-not-use-ultraviolet-uv-wands-give-unsafe-levels-radiation-fda-safety-communication

[OlDoinyo]

Definitely use gloves and PPE if wielding such gear. Ironically, the warning letters give a performance assessment of sorts, if one wanted to use such a device as a source for photographic or other work: The MerchSource product tops the output ratings at 7.6 W/M² with the other products putting out less.

[enricosavazzi]

If one really must have a powerful UVC source, there are affordable UVC fluorescent tubes readily available on Amazon with powers up to 55 W per tube (perhaps more).

 

[Warning: the above is not an invitation to use UVC sources, especially not without the use of full-body protective gear.]

[colinbm]

Enrico, these are over-kill & very dangerous for what we need, & inefficient for our needs.
These are 55w at 16", that works out as just over 3w per 1 inch of tube, so there is a lot of wasted light trying to fluoresce a mineral or flower.
There are 10volt 3watt UVC lamps that are 1-1/4" long, that illuminate a mineral or flower at the same intensity for that area.
Lamps like this are available on ebay & are powered by 12v through a ballast & be to be sure to NOT get the ozone ones !

 

I have used a reflector from a solar garden path light, which protects the user from 1/2 the light & focuses the beam on the subject that you want to fluoresce.
I think these are the best value for small UVC fluorescent photography, as long as the user covers their eyes & face with a polycarbonate face shield & cover all skin surfaces & with no living animals present.

[colinbm]

The safer, for humans & animals, alternative are the UVC 222nm Excimer tubes with filters to prevent any dangerous 240nm-300nm light.
https://www.bbtuv.com/product/portable-60w-222nm-uv-lamp-safe-and-harmless/
 

[Andy Perrin]

Honestly I know there’s some research showing 222nm is less dangerous than the 270’s, but I still wouldn’t trust it as exactly *safe*. Like, maybe if people still think so in 20 years more research, but it’s usually a bad idea to take just a few studies at face value. 
 

And yes I know you only said safER, colin, but still…people make logical jumps so I’m just pointing this out. 

[lukaszgryglicki]

Anything that emits below 250nm with strong output (222nm is great) would be AWESOME for me.

 

[dabateman]

1 hour ago, lukaszgryglicki said:

Anything that emits below 250nm with strong output (222nm is great) would be AWESOME for me.

 

I thought the cut off for the Nikon 105mm uv lens was 220nm. But looking through the original brochure and manual, that is only mentioned for the included UV filter. So the original UV Nikkor that you have might actually be able to see to 200nm.

 

UVNikkor105mmBrochure.pdf UVNikkorInstructions.pdf

[Bill De Jager]

On 7/25/2022 at 9:40 AM, Andy Perrin said:

Honestly I know there’s some research showing 222nm is less dangerous than the 270’s, but I still wouldn’t trust it as exactly *safe*. Like, maybe if people still think so in 20 years more research, but it’s usually a bad idea to take just a few studies at face value. 
 

And yes I know you only said safER, colin, but still…people make logical jumps so I’m just pointing this out. 

Earlier in the COVID pandemic I was definitely seeing UV in that range being touted as "safe" for use for casual disinfection by the general public.  I've believe it when there is thoroughly verified scientific investigation by a number of disinterested parties, considering also cumulative impacts over a period of use.

[ulf]

I have only seen claims that they are safe from companies that sell such light sources.

Are there any independent reliable scientific papers published and reviewed on the subject?

[JCDowdy]

Here is some guidance on the subject:

https://www.ies.org/standards/committee-reports/ies-committee-report-cr-2-20-faqs/

[colinbm]

I still treat Far UVC Excimer filtered to 222nm with the same precautions as I do with any UVC, that is polycarbonate face mask & all skin covered.
https://www.boeing.com/confident-travel/downloads/CAP-3_Disinfection_with_Far-UV.pdf

 

[Andy Perrin]

Colin, that’s smart. JCDowdy, that document surprised me, they seem almost cavalier. 

[JMC]

This whole 'UVC for cleaning' situation which has come about in the last few years really concerns me. I've been chatting on and off with someone who works in the Photobiology area for the NHS here in the UK. He's been evaluating and testing some of these types of lights. The general consensus is that 222nm is safe for exposure to skin and eyes, IF the light source is properly filtered to remove the more damaging longer wavelengths. The issue we have is the general consumer sees things like  'UVC is safe to use around the house', not realising that UVC covers a multitude of danger levels, depending on the specific wavelength. Ironically I'm writing this on my phone as for the 1st time in 2.5 years I'm laid up with Covid.

[Doug A]

@JMCget well soon. 

 

It is going to be very difficult to safeguard the public against "good" and "bad" UV. Education is one thing, but what about mass produced products that don't meet filtration specs? UV sanitization, in the public's hands, could be far more dangerous than the nasties being eliminated. 

 

Thanks,

Doug A

[JMC]

Cheers Doug. Yes it will be the cheapest mass produced products that will pose the biggest potential risk. Assuming they even produce UV - I've seen some which were nothing more than blue visible lights.

[JCDowdy]

3 hours ago, Andy Perrin said:

Colin, that’s smart. JCDowdy, that document surprised me, they seem almost cavalier. 

 

Well, I am glad you said "almost" since I am a member of the IES Photobiological Safety Committee.

 

The point of the guidance is to provide perspective on how GUV can be safely and properly employed by qualified persons.

[Andy Perrin]

The "almost" is because they support their statements with data. The "cavalier" is for the phrasing of guidance like this:

Quote

 There are no known long-term consequences from an accidental UV-C overexposure.^[18] Most eye injuries result from workers on ladders cleaning fixtures or working in the upper room without first turning off the fixtures.^[19] 

In context it's not so bad, but quoted in a news article that would convey a different impression. (I also wonder how one would even be able to attribute a skin cancer to a particular accidental overexposure given the years that would probably elapse between the events and the fact that cancer can be caused by other things.)

[JCDowdy]

I appreciate your point when comments are taken, or read, out of context things may be misconstrued. 

A pdf of the full committee report is available if you wish to delve deeper: https://media.ies.org/docs/standards/IES CR-2-20-V1a-20200507.pdf

This document was a priority effort in response to the COVID-19 pandemic. 

The penultimate comment in the background section is most pertinent.

"More-widespread use of GUV is often limited by safety concerns, but these are manageable and minor compared to potential infection prevention. Most of the public are not aware of its unique value in disinfection of air and contaminated surfaces." (emphasis added)

 

[Andy Perrin]

Yeah, I understand. I think applying some media-savviness might have been a good idea on the final edit, though. The public and the media tend to miss nuances, like the concept of harm being relative. Anyway, please take it as constructive criticism if you do a version 2.0. 

[JCDowdy]

Scientific criticism is necessary and always constructive.

Media-savviness IMHO is more of an art than a science. ;-)