Types Of UV Light - UV C, UV B, UV A   

Germicidal UVC - shortwave UV, which includes germicidal ultraviolet at 253.7nm wavelength - is used for air, surface and water disinfection. Unintentional overexposure to UV-C causes skin redness and eye irritation, but, according to Dr. Nardell, at The Harvard Medical School, it does not cause skin cancer or cataracts.

The longer wavelengths UV described below are NOT produced by germicidal UV lamps. They are part of the complete UV spectrum produced by the sun or some specialty lamps.

UV-B - A small, but dangerous part of sunlight. Most solar UV-B is absorbed by the ozone layer. Prolonged exposure causes sun burn and could result in unhealthy effects on the skin and eyes.

UV-A - Long wave UV causes tanning and premature skin aging.