UV radiation is one of the many electromagnetic frequencies emitted by the sun.
Of the total radiation emitted by the sun, a small percentage of UV rays reach the earth's surface. The atmosphere acts as a filter, through the ozone layer, and the percentage of radiation that reaches us is the appropriate amount for life on Earth.
There are three types of UV radiation and their properties are unique according to their wavelength.
UV radiation is between 100 nm and 400 nm:
UV-A goes from 315 to 400 nm
UV-B between 280 and 315 nm
UV-C is between 100 and 280 nm
In our daily lives we are already exposed to parts of the UV spectrum. Generally, excessive exposure to UV can produce adverse effects depending on the wavelength, type and duration of exposure.
UVC radiation includes the germicidal wavelength of 253.7nm which is used for air and water disinfection. Too much human exposure causes temporary redness of the skin and severe eye irritation, but no permanent damage such as skin cancer or cataract.
Microorganisms are simple organic structures that absorb UVC wavelengths, causing their destruction by photo-dissociation. The DNA or RNA of a microorganism is the first to be adversely affected due to its weaker molecular bonds. In hundredths of a second, it suffers irreparable damage. The subsequent loss of genetic instructions causes cell death and/or inability to replicate, rendering them harmless.
Yes, there are several scientific references for the effectiveness of UVC.
The first scientific observations on the germicidal effects of ultraviolet radiation started with Downes and Blunt (1877) who reported the inactivation of bacteria effectively. In 1885, Arlong and Duclaux demonstrated that sunlight has a lethal effect on Bacillus Arthacise the Tyrothrix Scaba. In 1903, Barnard and Morgan identified the ultraviolet (UV) spectrum as a 250 nanometre (nm) biocide, measured at 253.7nm by Ehrismann and Noethling (1932). The first use of UV for drinking water disinfection was reported to have been in France in Marseille in 1906.
Bedford (1927) and Gates (1929) were the first to establish UV doses for bacterial disinfection.
The first studies on virus irradiation were published by Rivers and Gates (1928) and Sturm (1932). In the 1930s, the first UV applications in hospitals to control infections (Wells, Hart and Sanger 1939) were seen.
The first attempts to use UV systems to control respiratory infections in schools occurred in the 1940s. (Wells 1943, Wheeler 1945, Perkins 1947, Higgons 1947).
In the 1950s, it was well established that UV irradiation was effective in disinfecting both air and surfaces.
In 1985 Philips published a guide to UV lamp applications for controlling bacterial growth.
With Hirano (1978) we have the first UV inactivation study on Murine coronavirus (MHV), followed by Weiss (1986), Bernevirus, Saknimit (1988), Canine coronavirus (CCV), Duan (2003), SARS coronavirusCov-P9, Darnell (2004), SARS coronavirus (Urbani), Walker (2007), Coronavirus.
Yes, Violet - Ultra Cleaner has a security system that allows its use in a safe way. After programming Violet - Ultra Cleaner there is a safety period in which the system does not start to allow people to leave the space to be sterilized. Violet - Ultra Cleaner also has motion sensors that turn the equipment off automatically in the presence of movement.
In case of motion sensors malfunction, the equipment does not start the execution click.
No, O3 is only formed for irradiation at wavelengths below 230 nm (between 100 nm and 230 nm, with a peak at 185 nm). On the contrary, between 240 and 315 nm, the UV light converts O3 into O2 by a photolysis process. The peak efficiency of this process occurs exactly at 245 nm.