UVC BACKGROUND
UV Resources: “UV-C Lamps – A Short (Wave) History”
- https://uvresources.com/uv-c-lamps-a-shortwave-history/
- “When people first see the futuristic blue hue of an ultraviolet-c (UV-C) lamp, some might think ultraviolet germicidal irradiation (UVGI) is a recent invention. Yet, knowledge of UV-C goes back well over 100 years, having gone through various phases of development. Here’s a brief history outlining some pivotal points (discovery, inception, development) in the century-long history of the various applications of UV-C.”
Food and Drug Administration: “Ultraviolet (UV) Radiation”
Health Europa: “Exploring the Advantages of UVC Disinfection”
UV Resources: “Upper Air UV-C – Improving IEQ”
- https://uvresources.com/upper-air-uv-c-improving-ieq/
- “Upper room UV-C is simple and decades old. A UV lamp in a specially designed fixture directs UV energy to the upper room area. The lamps 254 nanometer wavelength causes DNA damage to bacteria and viruses. The lamp also emits some visible light that appears blue.”
UVC EFFECTIVE AGAINST COVID-19
Food and Drug Administration: “UV Lights and Lamps: Ultraviolet-C Radiation, Disinfection, and Coronavirus”
National Center for Biotechnology Information: “Ultraviolet irradiation doses for coronavirus inactivation – review and analysis of coronavirus photoinactivation studies”
- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7273323/
- “The available data reveals large variations, which are apparently not caused by the coronaviruses but by the experimental conditions selected. If these are excluded as far as possible, it appears that coronaviruses are very UV sensitive. The upper limit determined for the log-reduction dose (90% reduction) is approximately 10.6 mJ/cm2 (median), while the true value is probably only 3.7 mJ/cm2 (median). Since coronaviruses do not differ structurally to any great exent, the SARS-CoV-2 virus – as well as possible future mutations – will very likely be highly UV sensitive, so that common UV disinfection procedures will inactivate the new SARS-CoV-2 virus without any further modification.”
Washington Post: “As America struggles to reopen schools and offices, how to clean coronavirus from the air”
New York Times: “Scientists Consider Indoor Ultraviolet Light to Zap Coronavirus in the Air”
- https://www.nytimes.com/2020/05/07/science/ultraviolet-light-coronavirus.html
- As society tries to rebound from the COVID-19 pandemic, some scientists believe that UVC technology can contain further spread of the infection. UV light essentially “kills” certain pathogens. The article also explores far-UVC, an even shorter and higher energy wavelength that appears to be even safer.
- “Some researchers hope a decades-old technology might get its moment and be deployed in stores, restaurants and schools.”
The American Journal of Infection Control: “Susceptibility of SARS-CoV-2 to UV irradiation”
National Public Radio: “Coronavirus FAQ: I'm Using A UV Light To Disinfect Stuff. Is That A Good Idea?”
- https://www.npr.org/sections/goatsandsoda/2021/01/29/959617806/coronavirus-faq-im-using-uv-light-to-disinfect-stuff-is-that-a-good-idea
- Although some recent studies have confirmed that SARS-COV-2 can be killed by ultraviolet light rays, it doesn't necessarily mean that UV lamps available commercially will do the job. UV commercial lamps lack the size of industrial lights and can only emit light from one angle which diminishes their capacity to sanitize. They are also not effective against SARS-COV-2. They are problematic as the rays can cause photokeratitis which is like a sunburn of the eye, causing severe eye pain or redness, blurry vision, eye twitching, light sensitivity or even temporary loss of vision. There is a risk of short- and long-term eye damage with these lights and as there is no evidence to confirm that they are a benefit against the SARS-COV-2 virus, there is no substitute for the approved protocols for the prevention.
- “Although it's been proven that ultraviolet-C light can kill the coronavirus in controlled research environments using specific doses, there's no guarantee that a lamp will...the UVC lamps you can buy online are often smaller than the industrial lamps used to kill viruses in labs.”
UVC SAFETY + HEALTH
National Institute of Occupational Safety and Health. USAGov. (n.d.).
Centers for Disease Control and Prevention: “Ultraviolet Radiation & the Work Environment (Revised. See: 74-121)”
- https://www.cdc.gov/niosh/docs/73-11005/default.html.
- The CDC discusses some of the dangers of Ultraviolet Radiation in the Workplace, which can represent some of the customers' fears.
- “Ultraviolet radiation may cause injury to the skin and to the eyes. Exposure can cause sunburn and prolonged exposure can result in aging of the skin and can even cause skin cancer.”
Global Health Delivery Online: “Guidelines for the Application of Upper-Room Ultraviolet Germicidal Irradiation for Preventing Transmission of Airborne Contagion—Part II: Design and Operation Guidance”
- https://www.ghdonline.org/uploads/GUIDELINES_PART_2.PDF
- “The diversity in structures currently being equipped with UVGI installations, plus the introduction of new designs of lamps and fixtures, have made it clear that an updated review of equipment performance factors and practical installation guidelines will be useful to interested parties. Illustrative examples are given of installations that have been made in a diverse set of facilities. In addition, representative figures are given to compare the cost of HVAC installations and UVGI installations that give an equivalent number of air changes based on equal levels of reduction in airborne microorganisms.”
ASHRAE: “Chapter 62: Ultraviolet Air and Surface Treatment”
- https://www.ashrae.org/file%20library/technical%20resources/covid-19/i-p_a19_ch62_uvairandsurfacetreatment.pdf
- “When used in combination with other mandatory air treatment modes, UVC provides an incremental benefit. For example, if a particulate filter removes 85% of a given agent in an incoming airstream and a UVC system with a single-pass efficiency of 85% for the same contaminant is installed in series with it, the combined filter/UVC system would have a combined single-pass capture and inactivation efficiency of approximately 98% (i.e., the incremental benefit of adding an 85% efficient device is only 13%).”
CDC: Environmental Control for Tuberculosis: Basic Upper-Room Ultraviolet Germicidal Irradiation Guidelines for Healthcare Settings
- https://www.cdc.gov/niosh/docs/2009-105/default.html
- “Research indicates that an appropriately designed and maintained upper-room UVGI system may kill or inactivate airborne TB bacteria and increase the protection afforded to healthcare workers while maintaining a safe level of UVGI in the occupied lower portion of the room. The purpose of this document is to examine the different parameters necessary for an effective upper-room UVGI system and to provide guidelines to healthcare managers, facility designers, engineers, and industrial hygienists on the parameters necessary to install and maintain an effective upper-room UVGI system.”
Far-UVC
Columbia University Irving Medical Center: “Far-UVC Light Safely Kills Airborne Coronaviruses”
- https://www.cuimc.columbia.edu/news/far-uvc-light-safely-kills-airborne-coronaviruses
- “Based on our results, continuous airborne disinfection with far-UVC light at the current regulatory limit could greatly reduce the level of airborne virus in indoor environments occupied by people.”
- The article explores far-UVC, a safer and potentially more effective means of reducing the spread of viruses like COVID-19. Based on the study’s results, continuous exposure to far-UVC light at the current regulatory limit would kill 90% of airborne viruses in about 8 minutes, 95% in about 11 minutes, 99% in about 16 minutes, and 99.9% in about 25 minutes.
Genetic Engineering & Biotechnology News: “UV Light That Is Safe for Humans but Bad for Bacteria and Viruses”
