UV-C LED-based disinfection can help in the battle against COVID-19

Author : Jonatan Klee | UV LED Account Manager | NICHIA

01 May 2021


Fuelled by the ongoing COVID-19 coronavirus pandemic, interest in the potential of UV-C LEDs for disinfection is growing rapidly. But although UV-C LED-based disinfection can be effective, bringing the technology to market in safe & effective products requires expertise.

The full version of this article was originally featured in the May 2021 issue of EPDT magazine [read the digital issue]. And sign up to receive your own copy each month.

Beyond the LED’s output power, other factors must be considered, explains Jonatan Klee, UV LED Account Manager at LED lighting specialist, NICHIA

The disinfection effect of UV radiation arrives by splitting chemical bonds between nucleic acids in the DNA of the virus or bacteria. Thanks to the subsequent formation of thymine dimers, the DNA can no longer duplicate during the cell-division process. This DNA damage is dependent upon the wavelength of the radiation source and the acting dose. Another factor to consider is that different pathogens have different sensitivity to UV-C. For instance, E. coli and staphylococcus are relatively easy to inactivate, while SARS-CoV-2 (which causes COVID-19) requires a dose some 5-17 times higher.

To exacerbate the challenge, it is worth indicating that UV light can also repair damaged DNA via a process known as photo-reactivation. Essentially, light in the range of 300-500nm activates the photolyase to repair DNA.

The best disinfection efficiency of UV-C LEDs for the inactivation of micro-organisms ranges between 260 and 270nm. Notably, LEDs can be produced in different wavelengths and distribute emission energy over a wide wavelength range.

Another advantage is that UV-C LEDs are completely ozone-free because they have no wavelengths less than 240nm. Notably, LEDs require no warm-up phase, with full power available immediately to make them ideal for timed on/off operation. LEDs can also be pulsed for higher output and, unlike mercury lamps, are suitable for dimming from 0-100%, ensuring their suitability in applications that demand variable intensity.

A further benefit of UV-C LEDs is their high irradiation intensity at close range. In turn, high density is achievable on the array. It is also possible to use lenses or reflectors for beam shaping to focus radiation energy on the surface requiring disinfection. Moreover, mercury-free LEDs provide high mechanical stability, offering both shockproof and waterproof attributes.

The main market disinfection opportunities for UV-C LED technology essentially comprise four areas: surface; HVAC (heating, ventilation &  air conditioning); water; and biomedical. Surface disinfection is the current focus of most UV-C LED developers, due to the specific benefits this technology offers, such as form factor and zero on/off time...

Read the full article in EPDT's May 2021 digital issue...

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