aureus into a room-sized chamber at a height of 5.5 feet. In one recent study, 12 researchers continually released the pathogen S. Far-UVC begins to inactivate pathogens within seconds upon their release from an infected source. With far-UVC, such air flow is not required. With ventilation and filtration systems, contaminated air is not disinfected immediately air must flow to the system before it can be cleaned, even if it must cross the entire room and infect other occupants along the way. 11įar-UVC is particularly effective at the rapid inactivation of airborne viruses and bacteria. 10 Far-UVC is also effective against typically UV-resistant pathogens, which is likely due to how far-UVC’s primary antimicrobial effect is through damage to proteins, whereas conventional UVC’s is through damage to DNA/RNA. Far-UVC can inactivate all tested bacteria (>23 species/spores), viruses (>23), and fungi (>5). Research has also demonstrated far-UVCs potential to rapidly mitigate disease transmission. Far-UVC systems should also not exceed the Threshold Limit Values set by The American Conference of Governmental Industrial Hygienists (ACGIH), which are currently 161 mJ/cm (eyes)² and 479 mJ/cm(skin)² over 8 hours. Filters should always be used with far-UVC devices. 5 6 7 8 While some older studies found unfiltered far-UVC to cause harm, 9 the adverse effects have been determined to be due to the wavelengths outside the 200-230 nm band, which are blocked by wavelength filtration. 4 Far-UVC causes no known significant damage to human skin and cell models even at doses significantly higher than required germicidal doses – as long as optical filters are used to block emissions outside the far-UVC range. 3 This “far-UVC” easily penetrates through microscopic viruses and bacteria, yet cannot penetrate through the outer, non-living layers of human skin and eyes. In 2013, scientists discovered that light in the band between 200-230 nm effectively inactivates pathogens while not causing harm to humans. Far-UVC SystemsĮarly studies in far-UVC systems have suggested that a narrow band of UVC – from 200-230 nm – may share conventional UVC’s germicidal properties, while avoiding health risks from direct exposure and allowing installation in a greater variety of building situations. 2 As direct exposure to conventional 254nm UVC can have carcinogenic and cataractogenic effects on humans, such systems must be carefully installed to avoid the risk of accidental exposure. These findings have led the CDC to recommend UVC disinfection in the unoccupied upper portion of spaces with insufficient HVAC systems. UVC has strong germicidal effects, especially at the 254 nm wavelength, and exposing air in the upper portion of a room to this wavelength has been shown to be highly effective at preventing the spread of SARS-CoV-2, influenza, tuberculosis, and other airborne pathogens. UVC light – a form of radiation with wavelengths between 100 to 280 nanometers (nm) on the electromagnetic spectrum – has been used for over 100 years to disinfect air, surfaces, and water (Reed, 2010). 1 Far-UVC may also sidestep the health concerns of conventional UVC systems, which we will describe first. Far-UVC can achieve impressive pathogen suppression – far greater than ventilation and filtration systems. become the world leader in reducing disease transmission by pursuing research, development, and regulation of far-UVC.įar-UVC is an emerging technology that could dramatically improve indoor air quality (IAQ) and reduce disease transmission. In particular, we believe the federal government can help the U.S. In your opinion, what approach(es) could the Federal government consider deploying to move decision makers/owners/managers toward making and sustaining improved ventilation, filtration, and air cleaning practices to reduce the risk of disease transmission?Īt IFP, we believe that the federal government should, while upgrading ventilation and filtration systems to meet today’s challenges, also invest in next-generation technologies that could substantially improve the efficiency, effectiveness, and reliability of air cleaning systems. We appreciate the opportunity to comment on Question 3.1 of EPA–HQ– OAR–2022–0794: The Institute for Progress (IFP) is a non-partisan think tank dedicated to accelerating scientific, technological, and industrial progress while safeguarding humanity’s future. Re: Request for Information: Better Indoor Air Quality Management To Help Reduce COVID–19 and Other Disease Transmission in Buildings: Technical Assistance Needs and Priorities To Improve Public Health Edwards, Director, Office of Radiation and Indoor Air
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