COVID-19 Virus Transmission and UVC Germicidal LED Disinfection

COVID-19 Virus Transmission

Early in July 2020 hundreds of scientists said that the SARS-CoV-2 (the virus that causes COVID-19) is Airborne [1]. The Centers for Disease Control and Prevention (CDC) just updated its coronavirus guidance, now stating that the coronavirus can spread through airborne particles [2]. Though the coronavirus is still thought to spread primarily through respiratory droplets passed from person to person, the CDC is recognizing that airborne transmission is also a threat since small particles can linger in the air for a period of minutes to hours, be inhaled, and lead to an infection. The CDC also acknowledges that these minuscule airborne particles can travel farther than 6 feet, particularly when people are talking, singing, or breathing heavily in indoor environments with poor ventilation [3].

The Airborne transmission consists of exposure to virus-containing respiratory smaller droplets and particles at greater distances of over 6ft. or over longer times (typically hours). The term Airborne Transmission is used to describe infections capable of being transmitted through exposure to infectious, pathogen-containing, small droplets and particles suspended in the air over long distances and that persist in the air for long times. The term “Aerosol” is used with respect to small droplets and particles and require distinct engineering controls to prevent occupational transmission of infectious pathogens like SARS-CoV-2.

Existing interventions to prevent the spread of SARS-CoV-2 virus include social distancing, use of masks in the community, hand hygiene, surface cleaning and disinfection, and air purification and ventilation systems UVC modifications. Recently, researchers have found that it is possible to completely inactivate SARS-CoV-2 virus using short wavelength Ultraviolet (UVC) Germicidal Irradiation (UVGI) [4].

Ultraviolet (UVC) Germicidal Irradiation

UVC Germicidal (UVGI) LED disinfection devices are a scientific innovation that provide efficient and thorough disinfection. Devices are available to provide both Surface and Air stream Disinfection. A UV Germicidal device is an electrical device that emits light in the UVC band of the electromagnetic spectrum (Ultraviolet C).

Ultraviolet Germicidal Irradiation (UVGI) is electromagnetic radiation that can destroy the ability of microorganisms to reproduce by causing photochemical changes in nucleic acids. Wavelengths in the UVC range are especially damaging to cells because they are absorbed by nucleic acids (UVGI Handbook 2009 ch2 2.1) – see chart below:

UVC radiation has effectively been used for decades to reduce the spread of bacteria, such as tuberculosis. For this reason, UVC lamps are often called “germicidal” lamps. In recent article the FDA reveals UVC radiation may also be effective in inactivating the SARS-CoV-2 and discusses wavelength, dose, and duration of UVC radiation required to inactivate the SARS-CoV-2 virus [5]. Recent CDC Guidelines for Environmental Infection Control recommends installing UVGI units in the exhaust air ducts of the HVAC system to supplement HEPA filtration or installing UVGI fixtures on or near the ceiling to irradiate upper room air [6]. (See below Chart “A” Scheme of UV-RNA-damaging mechanism by dimer formation and “B” Relative absorption spectra of RNA, relative emission UV spectrum)


The EPA (United States Environmental Protection Agency) investigated the Efficacy of Inactivation of Legionella pneumophila by Multiple-Wavelength UV LEDs. Compared to conventional mercury UV lamp, LED devices generating germicidal UV wavelengths (UV LED) are smaller, lighter, less fragile, and mercury-free. The EPA results shows the UV LED devices in the 265nm wavelength were most effective for inactivation of L. pneumophila with UV doses averaged approximately 2 mJ/cm2, followed by the 255nm UV LED and lastly the Low-Pressure Mercury UV Lamps with UV doses averaged approximately 3 mJ/cm2 [7]. This study and others indicate the higher efficacy of UV LED and for that reason Olympia’s patent-pending UV Air & Surface Disinfection solutions are designed to produce the optimal 265nm wavelength for disinfection to facilitate a healthy and safe indoor environment.


In a recent Guidance for the Re-Opening of Schools during COVID-19 Virus (SARS-Cov-2), ASHRAE (the American Society of Heating, Refrigerating and Air-Conditioning Engineers) recommends installing UVC lights in AHU’s (Air Handling Units) with minimum UV irradiation of 1,500 microwatts/cm2 when possible [8].

Additional studies such as the EPA’s Biological Inactivation Efficiency by HVAC In-Duct UVC Light Systems [9] and the IES (Illuminating Engineering Society) Photobiology Committee [10] concluded that UVGI can be used to reduce the spread of airborne infectious diseases such as tuberculosis, influenza virus, measles, SARS, and, presumably, SARS-CoV-2.

Olympia UVC LED Air Disinfection Devices

Olympia UVC LED Air Disinfection devices produce high energy UVC light in circulating air systems making them inhospitable environments for microorganisms such as Bacteria, Viruses, Mold, and other Pathogens. For its UV energy source Olympia uses UV LEDs that are solid state devices unlike mercury UV Lamp devices. Olympia’s UV LEDs do not contain hazardous material components such as mercury to dispose of at the end of the device’s life cycle, and do not emit toxic Ozone gas that when inhaled, can damage the lungs as other mercury UV Lamps might.

Two of Olympia “In Room” patent pending UVC Air Disinfection devices are illustrated below, the UVC Air Purifier Lay-in Troffer and the UVC Air Purifier Wall Unit:

Disinfection Solutions

In both UVC Air Disinfection devices the Air is circulated throughout the fixture, an Invisible UVC Light destroys the germs inside the fixture, and Disinfected Air comes out of the fixture.

Olympia’s UVC LED Air Disinfection devices use “UVC Irradiation” at wavelength of 265nm to provide optimum Germicidal Effectiveness, are designed to an ASHRAE established minimum UV irradiation of 1,500 microwatts/cm2 and are tested by a third-party lab for efficacy and product claims. Olympia is a Registered Establishment with the United States Environmental Protection Agency (US EPA) and warrantee its products to industry-leading standards with U.S. Based Tech Support & warehouses in New Jersey & California.

Olympia UVGI Performance & Safety is a Priority

Olympia’s patent-pending UV Air & Surface Disinfection solutions are designed to produce the optimal UVGI 265nm wavelength for disinfection to facilitate a healthy and safe indoor environment. All of Olympia UVC Air Disinfection Devices are designed to protect humans and pets from direct exposure to harmful UV radiation. There are a wide range of Olympia UVGI Systems available that are applicable to several environments, designed to provide Air and Surface Disinfection needs including:

(1) Olympia’s UVC Surface Disinfection Lamp

(2) Olympia’s UVC Germicidal Air Disinfection Wall Fixture

(3) Olympia’s UVC Germicidal Air Disinfection Lay-in Troffer

(4) Olympia’s UVC Surface & Air Disinfection LED Lamp