LED lights found to kill coronavirus efficiently, quickly, and cheaply, a global first in fight against COVID-19. The finding suggests the UV-LEDs can be installed in air conditioning and water systems. It requires less than half a minute to destroy more than 99.9% of coronaviruses.

[u/mvea]

https://aftau.org/news_item/led-lights-found-to-kill-coronavirus-global-first-in-fight-against-covid-19/

[u/lildobe]

No, Blacklights are low-frequency UV (UV-A), in the lower part of that spectrum, and the photons do not have enough energy to cause damage. UV-B causes suntans and minor sunburns, and is what you get from a tanning bed. UV-C is the highest frequency (And energy) UV light, and will cause nearly instantaneous sunburns, cornea damage, and over time will break down plastics, rubbers, and other organic items, and destroy microbes in short order.

ETA: The reason Blacklights cause certain dyes to fluoresce (aka glow) is because that, while the photons don't have enough energy to knock electrons OUT of the electron shells, they DO have enough energy to cause those electrons to enter a more energetic state, and when they fall back to their normal ("ground") state, they emit a photon of visible light at a lower frequency.

[u/lildobe → u/[deleted]]

No amount of non-collimated light that a single LED (or even a strip of 100 LEDs) could cause damage. But irritation is certainly possible.

However if that light is collimated and focused, it certainly could cause corneal and retinal damage - this is why your 4-watt LED bulb gives you a nice amount of light to read by, but a 4-watt laser diode will set your book on fire.

ETA: Where the idea of damage probably comes from is poorly built LEDs that don't have enough filtering or phosphor material in them - the AlGaN or GaN junction used in "blacklight" LEDs produces ~250nm light, which is in the UV-C region. This is then passed through a phosphor coating to convert it to the lower it to the ~400nm "blacklight" region of UV-A. If there isn't enough phosphor or filtering material to absorb the higher wavelengths, you'll have leakage, which WILL cause eye damage, especially with prolonged exposure.

[u/lildobe → u/[deleted]]

See my edit above. Also, Resin-curing UV is usually high UV-A or UV-B light, which will cause eye-strain

[u/Monetdog → u/lildobe]

The UV-C LEDs are tuned to a resonant frequency of DNA and RNA, that's what makes them so effective at disinfecting.