The Difference Between UV LED Sterilization and Visible Light Disinfection

By WPG AmericasJanuary 15, 2019

Over the past few years, ultraviolet (UV) LED has become a technology that the global water treatment industry is rapidly adopting, given its effectiveness and zero toxicity compared to chemical disinfection. The decline in LED costs and rising concerns regarding mercury vapor lamps is further driving the popularity of UV LED which is estimated to burgeon into a $1.1178 billion market by 2021.

While UV light — specifically UV-C — is known for its ability to destroy microorganisms, light in the visible spectrum between 400-405nm ranges also shows some germ-killing properties. Emitted from a functional light source, the 405nm light provides the advantage of safe and continuous disinfection, while illuminating the space at the same time.

So what’s the difference between these two types of light?

UV light is invisible to the naked eye and has a wavelength that ranges from 10nm and 400nm, which is shorter than visible light. There’s a difference in the way these two lights work against the germs. UV-C breaks the DNA of harmful micro-organisms to destroy them, while the 405nm light kills germs by causing photo-activation within their cells.

The two wavelengths also affect the human body in different ways. Depending on the distance and time of exposure, UV-C radiation may cause some temporary harm to the eyes and skin. However, 450nm light doesn’t harm the human body, which is why it can be safely used to sterilize large spaces that are frequented by people, e.g. public restrooms, medical facilities, and commercial kitchens.

Manufacturers like LG Innotek harness the 405nm wavelength to replicate the effect of sterilization by sunlight using indoor light. The company has recently launched their ‘Visible Disinfection Lighting’ modules, besides having broad portfolio of UV LEDs for sterilization applications. According to test results, LG Innotek’s 405nm Disinfection Lighting kills 99.9% of E.coli and S.aureus over a 16-hour exposure time.

‘Visible Disinfection Lighting’ will enable LED lighting manufacturers to produce differentiate lighting products that can be used across various types of LEDs including flat panel, tube and downlight.

Want to learn more about the advantages of using these LED products and the types of sterilization applications they are suitable for? Download our new white paper today!