What is UVC?

UV-C is one of many electromagnetic frequencies that typically emanate from the sun, but can also be generated artificially via UV-C lamps. Like other of these waveforms, its properties are unique to its wavelength. To synthesise this frequency, a glass tube is evacuated and refilled with argon at far below atmospheric pressure. Added to this is a small amount of mercury. When the mixture is energised (excited) it creates a glowing plasma of electrons that pass through the mercury vapour. As they strike mercury atoms, a mercury electron is liberated at a frequency representative of mercury’s spectral line, which is 253.7nm. The dominant emission (>90%) from these lamps is UV-C energy. Because of the spectral sensitivity of DNA, UV-C demonstrates significant germicidal properties.

What is FAR UVC?

Far-UVC is UV spectrum light at between 207- 222nm. Where it differs from 254nm is that initial tests have suggest that these wavelengths do not cause the human health issues associated with direct exposure to conventional germicidal UV light. The reason is that Far-UVC light has a range in biological materials of less than a few micrometers, and thus it cannot reach living human cells in the skin or eyes, being absorbed in the skin stratum, corneum or the ocular tear layer.

So then why are all Blubox units not using Far-UVC? There are 2 primary reasons.

  1. It still requires extensive peer-review study to enable it to be accepted by bodies such as the FDA for commercial use.
  2. It is still extremely expensive as it is not in mass production. All Blubox units would cost in magnitudes of 15-20 times more per unit.

The Blubox team is keeping a close watch on developments and as soon as Far-UVC is commercially viable we would look to integrate into our units.

Is UV-C harmful?

We are exposed to parts of the UV spectrum while outdoors. Generally, excessive UV exposure can produce adverse effects depending on wavelength, type and duration. UV response differs between individuals. UVA, for example, is known to cause skin cancer while UBV causes sunburn. These effects are due to excessive exposure.

UV-C includes the germicidal wavelength of 253.7nm and is typically used for air and water disinfection. Human overexposure causes temporary skin redness and harsh eye irritation (arc-eye) and chronic exposures to acute intense UVC can lead to cataract formation and retinal damage. The hazards associated with skin exposure are less hazardous than eye hazards; however, with the expanding use of higher-power ultraviolet equipment, the unprotected skin of personnel may be exposed to extremely hazardous levels.

Exceptional safety precautions should be used at all times when working with UV-C products.

Can UV-C kill viruses as well as bacteria?

UV-C kills living bacteria. Viruses are technically not living organisms, thus, we should correctly say UV-C inactivates viruses. Individual, energetic UV-C photons photochemically interact with the RNA and DNA molecules in a virus or bacterium to render these microbes non-infectious.

Can UV-C effectively inactivate the SARS-CoV-2 virus, responsible for COVID-19?

Alex Berezow, a microbiologist who has written on the topic, “UV light is lethal to bacteria and viruses because of its high frequency that scrambles and damages their nuclear material. When it damages the DNA (or RNA) code of these pathogens, it also triggers lethal mutations that prevent them from reproducing properly.”

While experts say there haven’t been conclusive tests showing that UV light can kill the coronavirus, Berezow says “UV light kills everything: bacteria, fungi, viruses. It should kill coronavirus.” (What we do know for sure is that it is effective against other viruses like the flu.)

Definition of disinfection and sterilization

Disinfection and sterilisation are both decontamination processes. While disinfection is the process of eliminating or reducing harmful microorganisms from inanimate objects and surfaces, sterilisation is the process of killing all microorganisms.

“A disinfectant kills microorganisms, but not the spores,” explains Jackie Dorst, RDH, BS, a “Safe Practices” infection prevention consultant and speaker. “Microorganisms can form spores. A spore has a protective membrane around it, or a hard shell, that protects the microorganisms from disinfectant chemicals. So, the definition is, basically, that a disinfectant kills vegetative microorganisms, but not the spores.

“Sterilisation means that all life forms are killed, including the hard-to-kill spores,” she continues. “It’s referred to as asepsis, or a sterile environment (the absence of bacteria, viruses, and other microorganisms), meaning that you’ve reduced all of those vegetative and spore-forming microorganisms. They don’t survive and they cannot transmit or reproduce anymore.”

Benefits of UVC Sterilization


The most important benefit of UV light disinfection is that it is non-toxic. Unlike harsh chemicals that are often used in cleaning and sanitisation products, UV light is environmentally friendly. UV light disinfection is a physical process, not a chemical one.


The next key benefit of disinfecting with UV light is that this method of disinfection can me far more effective than other methods. UV light kills a wide array of harmful organisms.

For example, did you know that UV light destroys moulds and spores? Other disinfection methods may not – or they may leave a damp environment where fungi can thrive. Since UV disinfection is a dry method, you can be sure that it will take care of existing mould and prevent its growth in the future.

Bacteria Immunity

Unlike traditional disinfection methods, UV light disinfection is a physical method for killing bacteria.  Therefore, bacteria in question cannot build immunity to it. That’s a huge plus, particularly for hospitals and assisted living facilities.

Cost effective

UV disinfection is an affordable sanitisation method. People sometimes assume that it’s costly because it uses technology instead of chemicals, but that’s not the case.

Though the one-off initial cost may appear more costly, when amortised over a time period it is significantly less costly when factoring time and materials.