UV rays are ultraviolet rays that cannot be detected by the human eye. They are emitted by the sun but only 5% of the rays manage to cross the ozone layer. UV-C rays are a component of ultraviolet rays and are fully absorbed by our atmosphere so they are not naturally present on earth.
UV-C rays are extremely high energy rays, a property that gives them the power to alter biological molecules such as DNA. When bacteria or viruses are exposed to UV-C rays, the structure of their DNA is modified. This modification stops their growth and spread. This is then known as sterilisation.
The sterilisation of a surface depends on the exposure time and the power of the lamps (or LED). If the power of the lamps is sufficient, it takes around 10 seconds to destroy the virus responsible for COVID-19, SARS-CoV-2. The UV-C lamps are used to treat surfaces (operating theatre, public transport, etc.), liquids (stagnant water, etc.) and, of course, air!
In its EOLIS Air Manager air purifiers, NatéoSanté uses lamps with a dominant wavelength of 254 nanometres, thereby ensuring the germicidal/virucidal character. This is not always the case with lamps which have a dominant wavelength of 270 to 280 nanometres.