What is Germicidal UV, and what is UV-C Lighting?
Updated: Jul 14, 2021
The 2014 outbreak of the Ebola virus and the recent spread of the novel coronavirus disease 2019 (COVID-19) has renewed interest in germicidal ultraviolet (GUV) lamps for disinfection. UV radiant energy was first used for disinfecting surfaces in 1877,1,2 for water in 1910,3 and for air in 1935.4 GUV’s use in recent decades has been largely limited in the U.S. to water treatment facilities and hidden (shielded) in heating and air-conditioning ductwork, or used in biological laboratories. A germicidal lamp is an electric light that produces ultraviolet C (UVC) light. This short-wave ultraviolet light disrupts DNA base pairing, causing the formation of pyrimidine dimers, and leads to the inactivation of bacteria, viruses, and protozoa. It can also be used to produce ozone for water disinfection. They are used in ultraviolet germicidal irradiation (UVGI).
Is all Ultraviolet considered Germicidal?
No. Germicidal ultraviolet (GUV) – refers to short-wavelength ultraviolet “light” (radiant energy) that has been shown to kill bacteria and spores and to inactivate viruses. Wavelengths in the photobiological ultraviolet spectral band known as the “UV-C,” from 200 to 280 nanometers (nm), have been shown to be the most effective for disinfection, although longer, less energetic UV can also disinfect if applied in much greater doses. UV-C wavelengths comprise photons (particles of light) that are the most energetic in the optical spectrum (comprising UV, visible, and infrared) and therefore are the most photochemically active.
What are the factors that affect UV's capacity to be germicidal?
There are many factors that affect the efficacy of light in this particular spectrum to be germicidal.
Wavelength- Wavelengths in the photobiological ultraviolet spectral band known as the “UV-C,” from 200 to 280 nanometers (nm) have been shown to be the most effective for disinfection. Lifegate Pharma's Nova Mini operates in an optimum range of 253.7 nm which falls in the upper spectrum of this wavelength and thereby has increased disinfection capabilities vs other more common disinfectant solutions and methods.
Dosage- When it comes to understanding dosage in relation to UVC light in particular, the most important factors are proximity and duration. To put this in layman's terms, one must ask yourself two questions, "How close?" and "For how long?"
Can this be explained better, or better yet, simpler?
UVC light works to disinfect the surfaces by light rays that pass through the air within the wavelength of 200-280 nm, with increased energy that breaks the RNA and DNA of the virus, bacteria, spores, and even coronavirus. Light rays pass through the air and hit the back of our retina which also give us the beauty of better vision and brighter colors. The phenomena are the same however the difference is this band of UV is not visible to the eye.
K.I.S.S
Keep it simple silly. Stop confusing these folks with jargon. When you turn on a light in the room, the whole room goes bright not just the area where the bulb or lamp is situated. Give the light a higher wattage and even a small light will light up a whole room. The closer you are to the light, the brighter it will be. Hence the closer your proximity to your UVC light the stronger the disinfection effect it poses.
How long will it take?
Since we live in a world where time is money, the duration of time your disinfection process is going to take is always going to be a point of discussion. The simple answer is,
the closer the proximity=the shorter the duration of exposure
the larger the space=the longer the dosage
If you keep these two rules in mind, you wll hardly ever go wrong
Can UV-C effectively inactivate coronavirus?
Yes, if the virus is directly illuminated by UV-C at the effective dose level. UV-C can play an effective role with other methods of disinfection, but it is essential that individuals be protected to prevent UV hazards to the eyes and skin. Let us clarify that it is not a substitute for cleaning and hygiene, but acts as a catalyst
The all-important question. Will UV-C light harm me?
UV-C is almost entirely absorbed by the outer dead layer (stratum corneum) and outer skin (outer epidermis), with very limited penetration to the deeper cellular layers of skin where new cells are constantly created. For comparison, the current daily safety limit of 254-nm UV-C for 8 hours is 6.0 mJ/cm2 , whereas less than ten minutes of summer sun exposure at a UV Index of 10 can deliver the equivalent limiting daily safety dose.
So there you have it, you are in danger on that beach in Barcelona on your upcoming bachelor trip, (once the pandemic ends) and i don't foresee you skimping out on that leisure time my dear friend.
Yours sincerely,
David Mathias
Managing Director at Lifegate Pharma