What is Germicidal Ultraviolet?

A Specific Type of UV Light

Diagram of the Electromagnetic Spectrum

Germicidal ultraviolet light (UV-C) is part of a larger category: Ultraviolet light, which also includes UV-A and UV-B rays. As shown in the electromagnetic spectrum diagram, ultraviolet light is in between x-rays and visible light.

While all 3 of these subcategories (UV-A, UV-B, and UV-C) are produced by the sun, the earth’s ozone prevents some UV-B and all UV-C rays from getting through. Since UV-C light is harmful to eyes and skin, direct air and surface disinfection must only be used in unoccupied areas (or where occupants are wearing proper protective gear).

Germicidal Ultraviolet Kills Germs

As shown in this table, UV-C differs from UV-A and UV-B in the size of its wavelengths. Atlantic Ultraviolet Corporation’s STER-L-RAY® Germicidal UV lamps produce 95% of their rays at 254 nanometers, the specific wavelength that destroys the DNA structure of harmful bacteria, viruses, and mold. After the right UV dose, these microorganisms are unable to reproduce — and so they die. View our list of UV-C doses to neutralize many pathogens.

UV TypeWavelength Range (nanometers)
UV-A315–400 nm
UV-B280–315 nm
UV-C100–280 nm

Its Benefits and Limitations

How to Achieve the Correct UV Dose

Germicidal ultraviolet disinfection is rapid, low-maintenance, and does not use chemicals or produce byproducts. To achieve proper disinfection of water, air, or surfaces, each must be exposed to 254 nanometers of UV-C intensity for the appropriate amount of time.

When used to disinfect water, UV-C should be the final step before use. It is intended to treat visually clear water that is not colored, cloudy, or turbid. When used for surface disinfection, multiple treatment cycles may be required for places where UV rays are obstructed.

Uses for Germicidal Ultraviolet

Germicidal UV technology has many residential, commercial, and industrial uses. Browse our application pages and UV blog to learn more. Our team of UV application specialists can be reached at (631) 273-0500 or Sales@AtlanticUV.com with any questions you may have.