[SAFETY WARNING] News article - Far UVC doesn't damage skin/eyes!

[JMC]

SAFETY WARNING: 

UV-C is dangerous to your eyes and your skin.

UVP DOES NOT SUPPORT USING UV-C ILLUMINATION.

[UV SAFETY] UV-C Light Dangers

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This just came up on my youtube feed.

 

 

It's a video from a couple of years ago, and the key message is that Far UVC doesn't damage the skin or eyes, because it cannot penetrate them.

 

Now I'm not sure what they are calling conventional UV light, but my experience with UVC has been that it will most definitely burn the skin. How on earth is the consumer supposed to know what Far UVC is, as opposed to plain old normal UVC?

 

There is actually a paper in Nature, which talks about Far UVC as being 207-222nm (https://www.nature.c...598-018-21058-w) and it not damaging the skin.

 

I wonder how may people see this type of information and then go and buy 254nm lamps expecting them to be safe for skin exposure?

 

Anyway, sharing as I find it quite shocking really about how misleading it could be to use these types of light sources on skin, without knowing what you are doing.

[nfoto]

Norwegian scientists recently abandoned a prestigious project to "solve" the economically damage of sea lice infestations to our large salmon industry. They used UV-C and, not surprisingly perhaps, found the cure caused much more ill effects than the problem itself. The salmon became "sunburnt", had extensive eye and skin damage, and whilst the sea lice indeed did succumb, so did their hosts as well.

[Stefano]

In UVC people are probably dark. Don’t want to try.

[dabateman]

Not going to try UVC portraits. But have thought about imaging pig skin, chicken skin and some fish. Maybe one day.

 

Birna,

I sometimes read

"The patient tolerated the treatment...."

 

Which is similar to your salmon experience.

 

The truly scarey thing is UVC lights will become common after the current state of the world. We will see them everywhere. Hopefully some people will keep the dangers in mind and we can control the new second hand smoke.

[OlDoinyo]

Since air is not very transparent at these wavelengths, I suspect this debate is mostly academic. But it may be that penetration is very shalloe in this range, and perhaps little of such UV would reach living cells.

[Andy Perrin]

Since air is not very transparent at these wavelengths, I suspect this debate is mostly academic. But it may be that penetration is very shalloe in this range, and perhaps little of such UV would reach living cells.

I have heard that and I believe it is true if you consider distances of dozens of meters, but dabateman is having no trouble taking photos at ordinary distances, so you can easily get a significant dose if you are a meter or two away. Not so academic if the lights are everywhere.

[dabateman]

Jonathan have a look at the paper:

https://www.researchgate.net/publication/303872253_207-nm_UV_Light-A_Promising_Tool_for_Safe_Low-Cost_Reduction_of_Surgical_Site_Infections_II_In-Vivo_Safety_Studies

 

I am not a skin expert, so no idea if there claims are well supported.

They are using only 222nm and 207nm light.

I would love to get one of those Kr-Br or iodine vapour lamps which output strong 207nm. Would help me image in the low UV. All my 185nm mercury lamps have a strong 254nm peak. Also if you tighten the bulb using the fused silica tube, your off shift the glass causing a leak to the pressure and then will get substantial more 254nm than 185nm. That my current problem. I can't get high enough pressure to favor the 185nm line.

 

OlDoinyo,

There is a surprising amount of UVC , even 185nm that can be imaged. I was able to image 4 feet away from the refected source. Using isopropyl alcohol as a control. Its dark in the low UV, but not at 254nm. Its absorption peak max is 205nm.

Water I couldn't see dark, its in the low 190 to 185nm range. But my filter peak is 193nm and my quantum efficiency of my KSS imager also drops off down there.

[dabateman]

I found his spin off company:

https://sterilray.com/

 

Also can be purchased from more reputable ushio:

https://www.ushio.com/product/care222-mercury-free-far-uv-c-excimer/

[JMC]

Thanks for the paper David, I'll take a read.

 

The issue I'd have with it is not the claim that it doesn't penetrate the skin to the viable parts, I sort of get why that would be the case (counter intuitive though it seems), it's the effect it would have in the stratum corneum that bothers me.

 

If it kills off pretty much everything, bacteria and virus wise, then that leaves the skin open to colonisation by Staph Aureus which is a very bad thing. Being so high energy it will damage proteins and lipids in the Stratum Corneum, which will compromise the skin barrier. It's a bit like if you have atopic dermatitis - the bacterial distribution is skewed and the skin barrier is compromised. This leads to increased irritation, and a potential of allergic sensitization.

 

I certainly wouldn't be shining UVC (of any flavour) on my skin until I knew a lot more about the potential side effects.