Technical
UV-C at the effective dose level . Further studies need to be done about the usage of far UV-C for disinfection , but it appears that low-dose-rate , far-UV-C exposure can potentially safely provide a major reduction in the ambient level of airborne coronaviruses including SARS- CoV-2 .
Stringent safety requirements , considerations and guidelines should be followed when using UVGI to reduce health hazards to the eyes and skin .
Contact qualified professionals for additional information and implementation of UV-C lighting .
Please note that the information in this article was compiled in 2020 , and any information that became made available after 2020 is not necessarily included in this article .
ACKNOWLEDGMENTS This white paper was prepared by : Pieter de Bod , Laura Cowley , Lilian Rodriguez Fu .
NOMENCLATURE CDC Centres for Disease Control and Prevention ( CDC ) Disinfection Compared to sterilisation , a less lethal process of inactivating microorganisms . DNA
Exposure
The molecule inside cells that contains the genetic information responsible for the development and function of an organism .
Being subjected to infectious agents , irradiation , particulates , or chemicals that could have harmful effects .
Germicidal UV ( GUV ) The practice of using UV-C to disinfect . HEPA
Irradiance
Being , using , or containing a filter usually designed to remove 99.97 % of airborne particles measuring 0.3 micrometres or greater in diameter passing through it .
Power of electromagnetic radiation incident on a surface per unit surface area , typically reported in microwatts per square centimetre ( μW / cm₂ ).
Mycobacterium tuberculosis Is a species of pathogenic bacteria in the family Mycobacteriaceae and the causative agent of TB . Mega Joule ( mJ ) A unit of work or energy , equal to one million joules . Microwatt ( μW ) One millionth of a watt . Nano meter ( nm ) One billionth of a meter . Photon
RNA
SARS-CoV-2 severe acute respiratory syndrome coronavirus 2 .
A particle representing a quantum of light or other electromagnetic radiation . A photon carries energy proportional to the radiation frequency but has zero rest mass .
Ribonucleic acid It is a virus that causes respiratory illness in humans .
TB Tuberculosis is a disease caused by germs that are spread from person to person through the air . TB usually affects the lungs , but it can also affect other parts of the body , such as the brain , the kidneys , or the spine . A person with TB can die if they do not get treatment .
Ultraviolet germicidal irradiation ( UVGI )
Ultraviolet radiation that inactivates microorganisms . UVC energy is generated by germicidal lamps that kill or inactivate microorganisms by emitting radiation predominantly at a wavelength of 253.7 nm .
Ultraviolet radiation Optical radiation with a wavelength shorter than that of visible radiation . The range between 100 and 400 nm is commonly subdivided into UVA : 315 to 400 nm UVB : 280 to 315 nm UVC : 200 to 280 nm Vacuum UV 100 to 200 nm .
UV dose Product of UV irradiance and specific exposure time on a given microorganism or surface , typically reported in millijoules per square centimetre ( mJ / cm ²).
Wavelength
Distance between repeating units of a wave pattern , commonly designated by the Greek letter lambda ( λ ).
ENDNOTES i https :// www . ies . org / fires / designing-a-UVC-germicidal-system /? utm _ source = IES & utm _ medium = Email & utm _ campaign = Client % 20
Updates &_ zs = sEENX &_ zl = 9iC82 ii Ashrae Applications Handbook – 2019 , Chapter 62 . iii
Brickner , P . W ., R . L . Vincent , M . First , E . Nardell , M . Murray , and W . Kaufman . 2003 . The application of ultraviolet germicidal irradiation to control transmission of airborne disease : Bioterrorism countermeasure . Public Health Report 118 ( 2 ): 99-114 . iv https :// www . ies . org / standards / committee-reports / ies-committee-report-cr-2-20-faqs / v Wang T , MacGregor SJ , Anderson JG , Woolsey GA . Pulsed ultra-violet inactivation spectrum of Escherichia coli . Water Res .
2005 ; 39 ( 13 ): 2921-5 .
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