What is UVC?The ultraviolet radiation of the sun can be divided into three bands (100nm-400nm) according to the ultraviolet radiation of the sun: a) UVA: 315-400nm, without bactericidal and viral effects, but can be used to slow down the growth of bacteria, which will lead to skin tanning. b) UVB: 280-315nm, high energy, can kill bacteria, but it has poor effect on viruses with much smaller particle size. This band has a great impact on the human body. Proper irradiation can treat and prevent rickets. Long term irradiation may also damage the skin and eyes, and even cause skin cancer, cataract, decline of immune system function and other diseases; c) UVC: 200-280nm, high energy, very suitable for killing microorganisms. d) VUV, with a wavelength range of 100-200nm, is almost absorbed by ozone, water vapor, oxygen and carbon dioxide and cannot reach the ground. All ultraviolet rays are invisible.
Can all ultraviolet rays be used as bactericidal UV?No, germicidal ultraviolet (GUV) refers to short wave ultraviolet rays that have been proved to kill bacteria and spores and inactivate viruses.
Can UV-C kill viruses and bacteria?Yes, UV-C is absorbed by the DNA and RNA of bacteria, viruses and other cells. The nucleic acid structure of cells that absorb UV-C is damaged due to the formation of dimers, loss of reproductive ability and death. This is the mechanism of UV-C sterilization and inactivation of viruses.
Can UV-C effectively inactivate the sars-cov-2 virus that causes covid-19?Yes, if the virus is directly irradiated by UV-C at the effective dose level. UV-C can play an effective role together with other disinfection methods.
What is far UVC?Far UVC (200-230nm) is a region in the UV-C (200-280nm) spectrum, which can independently and continuously kill viruses, bacteria and fungi in the occupied space, and is safe for skin and eyes. This is very important to curb and mitigate the emerging threat of new crown and other infectious diseases. It is an important supplement to the existing sanitation and disinfection technology and a new multi pronged choice to prevent the spread of existing and emerging infectious diseases.
How was far UVC discovered?In 2018, Professor David Brenner published a paper on 222nm far UVC in the authoritative scientific journal Nature, which confirmed that far UVC did not harm skin and eyes. In 2020, Professor David Brenner published a peer-reviewed paper in the journal nature again, which confirmed that far UVC can effectively inactivate coronavirus and is safe for human body.
Does the National Health Commission agree?The New Coronavirus pneumonia prevention and control plan issued by the national health and Health Commission pointed out that the virus is sensitive to ultraviolet radiation.
Why is there no damage to the skin?Due to its short wavelength, far UVC has limited penetration in the tissue, and the transmittance to keratin is only 0.01%. It can not penetrate the cuticle of the skin, so it will not cause skin aging or skin cancer. Ultraviolet rays with a wavelength of 254 nm can penetrate the stratum corneum and destroy the DNA in our skin cells, leading to burns and skin cancer.