UV Light Sanitiser

Do UV light sanitisers really work and can they prevent the spread of corona-virus?


In principle yes, in practice it depends. UV will kill bacteria and viruses but the time it takes depends on the microbe, the distance away, the power of the lamp and a few other things. So unless the manufacturer says under conditions XYZ it will kill coronavirus and you meet those conditions you don’t know.

As the WHO says, using this as a method of hand sanitisation is not recommended.


They can kill bacteria and viruses…but this comes with a big however.

For UV to kill, it needs time and an intensity of light strong enough to damage the virus/bacteria.

Notwithstanding this, UV light at sufficient intensity only works where light can directly hit the bacteria/virus. For most surfaces, this is nearly impossible unless the surface is very smooth (think glass) and free of any cracks, crevices or roughness.


I think it would depend on the wavelength of the UV light. The longer UV wavelengths nearest visible light, around 200-300 nanometres would have little effect I suspect, since the virus size is around 80-90nm. Extreme UV / UVC with wavelengths nearer X-rays of around 10-50nm would be much more effective. Larger bacteria can be killed by the longer wavelength UV though, but that is not the target here.
However, you do not want to have extreme UV on your skin, and especially your eyes, as serious damage will be done.


The WHO warns against using UV sterilising lamps for such purposes…

Can an ultraviolet disinfection lamp kill the new coronavirus?

UV lamps should not be used to sterilize hands or other areas of skin as UV radiation can cause skin irritation.

And they failed to mention the possibly skin cancer.


UV light can damage a lot of things as well. Its not great for plastics, nor too much for fabrics.

I’ve seen a lot of UV light sanitisers marketed for mobile phones lately, which is a good theory because phones are GERMY AF. But better than spending $130 on a box with a light that may or may not actually kill any germs on your phone would be spending around $100 on a waterproof phone case you can wash with soap and water, and usually offers some pretty good drop protection too.
I’ve got a Catalyst Waterproof case on my iphone, which is IP68 rated. My phone gets washed when my hands get washed.



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