Eli5: how does uv light clean stuff?


I came across a wireless charger that cleans cell phones with uv light. Also advertised that it cleaned credit cards, key fobs and even pacifiers. Is it possible to clean germs with lights? I don’t understand this sorcery

In: Chemistry

It doesn’t clean stuff, but it kills. Specifically it kills microorganism.

The microorganism ar actually what we worry the most about when we worry about stuff being dirty. Dirt doesn’t make you sick. Bacteria do and UV-light can kill bacteria.

This technology is used to for example make water safer to drink. It works well enough and is widely used around the world.

I would like caution though that a cheap USB-charger likely isn’t going to be all that good at killing germs with UV light. I would not rely on the claims made by the manufacturer to keep you healthy.

UV light at sufficient levels scrambles germ’s DNA, interfering with reproduction. A small number of pathogens is unlikely to produce enough toxins or otherwise do serious harm, it’s the multiplication into colonies that does the damage.