Efficacy
Regarding disinfecting efficacy
How UV light disinfects bacteria and viruses? 200-280nm germicidal UV light destroys the DNA/RNA of bacteria and viruses, making them unable to reproduce, rendering them harmless (even though the organism may not be killed). 254nm and 265nm UV light used in the past is harmful to people, but 222nm wavelength UV is harmless to humans and mammals and does not cause cancer or burns.
Irridiation time required for 99% disinfection
UV light works against microorganism which has RND/DNA such as viruses and bacteria. Also, bacteria or virus won’t be resistant agains ultraviolet light differently from drugs or chemicals.
Further Reading
News Release: “Kobe University-Ushio Inc. Joint Study Shows Irradiation of Filtered 222 nm Far UV-C Light on Human Skin Reduces Bacterial Counts While Causing No Skin Damage” (2020)
News Release: “Kobe University-Ushio Inc. Joint Study Finds Repetitive Irradiation with 222 nm UV-C Does Not Cause Skin Cancer” (2020)
Ushio Inc. / National University Hospital Singapore succeed in bacterial disinfection of injuries using 222 nm ultraviolet (2017)
DIRECTIVE 2006/25/EC OF THE EUROPEAN PARLIAMENT AND OF THE COUNCIL of 5 April 2006 on the minimum health and safety requirements regarding the exposure of workers to risks arising from physical agents (artificial optical radiation) (19th individual Directive within the meaning of Article 16(1) of Directive 89/391/EEC)
Care222® excimer lamps from Ushio America, Inc.
Far-UVC light (222 nm) efficiently and safely inactivates airborne human coronaviruses
Exploratory clinical trial on the safety and bactericidal effect of 222-nm ultraviolet C irradiation in healthy humans
