Ever since scientists first discovered the existence of viruses and harmful bacteria, various methods have been tried to protect people from the dangers of exposure to them.

As early as 1845, it was known that these microorganisms could be adversely affected by exposure to direct light.

Research in this area quickly revealed that applying certain types of light to air and surfaces could be an extremely effective way to guard us all against the risk of bacterial and viral infection.

In particular, ultraviolet light (UVC radiation) was proved to be the most successful in disinfecting air, water and non-porous surfaces.

UVC radiation was first used in the 1930s to tackle the spread of tuberculosis and measles. But as those diseases became less prevalent, UVC treatments became less commonplace.

How does UVC radiation work?

Direct exposure to UVC radiation destroys the outer skin (the protein coating) of all viruses, including SARS-Cov-2, the strain that leads to Covid-19. This breakdown in the DNA structure renders the virus unable to reproduce or be transmitted any further.

Using portable lamps or overhead lights to emit UVC radiation over exposed surfaces in a room will inactivate, or disable, any viruses found in those areas. UVC lamps are often called “germicidal” because of their effectiveness in this respect.

Different viruses require different levels of exposure to be inactivated, or disabled. For example, the coronavirus that can cause the common cold (HCoV-OC43) would be disabled very quickly, while achieving protection from SAR-Cov-2 requires a longer exposure time. Many UVC lamps currently sold for home usage would be ineffective, for that reason.

This is why it is essential to assess the “kill-rating” of any UVC device if it is to be used to complement a deep cleaning procedure to protect public settings.

How does UVC compare with other forms of ultraviolet light?

It’s also important to be aware of the different types of ultraviolet light and their properties. UVA, UVB and UVC are all part of the light energy spectrum that emanates from the Sun.

o   UVA and UVB radiation are both much less effective than UVC light in disabling viruses (including coronavirus) or in killing harmful bacteria

o   UVC and UVB radiation exposure to human skin and eyes must be avoided

o   UVA radiation is less hazardous and is used in sunbeds and sunlamps.


UVA and UVB rays both penetrate the Earth’s atmosphere, while the shorter wavelength UVC does not. This may explain why viruses have no natural ability to withstand UVC light, because it can only be produced artificially.

UVC light ranges in wavelength from 200 to 280 nanometers and has the most energy of all three types of UV light. Only these UVC wavelengths have a destructive effect on the genetic material inside viruses and other microbes, stopping them from being infectious, or transmissible.

UVC light is also proven to destroy the potency of the SARS-CoV-2 virus, and its ability to infect a host. This applies to all other coronaviruses as well.


In summary, UVC light has been proven to inactivate viruses, including the SARS-CoV-2 coronavirus. It also kills all bacteria. It is powerful disinfectant qualities are clearly demonstrated.



Designed and developed to deliver a 22mJcm2 dose over a three-metre radius in just 15 minutes, our Muv-X Room steriliser achieves a 6-log kill rating (99.9999% ‘kill’ rate) in disabling all viruses and killing harmful bacteria.

That can make all the difference when you’re responsible for protecting people in public settings from potential exposure to the risk of infection from Covid-19.

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