Ultraviolet C (UVC)

Ultraviolet C (UVC) is a high-energy portion of the ultraviolet light spectrum with wavelengths roughly between 100 and 280 nanometers. It’s the most energetic—and most biologically active—type of UV radiation.

What makes UVC special

UVC light is highly effective at destroying microorganisms. It works by damaging their DNA or RNA, which prevents them from reproducing. That’s why it’s widely used for disinfection and sterilization.

Common uses

• Water purification – killing bacteria and viruses in drinking water
• Air sterilization – in hospitals, labs, HVAC systems
• Surface disinfection – tools, medical equipment, packaging
• Consumer devices – phone sanitizers, UV boxes (though effectiveness varies)

Natural vs artificial

The Sun does produce UVC, but almost all of it is absorbed by Earth’s atmosphere, especially the ozone layer. So the UVC we encounter is almost always from artificial sources, like mercury lamps or UV LEDs.

Safety considerations

UVC is effective—but also dangerous:

• Can cause severe skin burns and eye injuries (like photokeratitis)
• Even short exposure can be harmful
• Should only be used in controlled environments or enclosed devices