Is Ultraviolet light (UVC) effective against contaminants and SARS-CoV-2?
UV disinfection is a validated technology for the abatement of pathogens. The most common type of UV light for germicidal applications is a low-pressure lamp, emitting around 254 nm (UVC). UVC photons damage the genomic system of microorganisms.
However, while these lamps disinfect unoccupied spaces, direct exposure is not possible since it can be a health hazard, both to the skin and eye.
In a recent study, the scientists concluded that a 75mJ/cm2 dose of UV light could kill the virus behind COVID-19.
Unfortunately, it turns out that most of UV-C lamp available on e-commerce sites worldwide can’t meet this power demand.
Furthermore, UV light strength varies with the square of the distance. This means that using common UV lights to disinfect large areas like buses, planes, shops, malls and sports centres is impractical.
In conclusion, the effectiveness of germicidal UV depends on the length of time a microorganism is exposed to UV and on the intensity and wavelength of the UV radiation.