Germicidal Ultraviolet Light


There is a great deal of interest in the use of ultraviolet light to mitigate germs and viruses. The technology of germicidal lighting is referred to as germicidal UV, or GUV. Technically, the GUV spectrum is defined as UV-C. While the UV-C part of the spectrum is an effective killer of COVID-19 and similar viruses, it must be used carefully to be both effective and safe. Information on this site is compiled to help promote the safe and effective use of GUV in residential settings.

 

 

UVC Germicidal Devices: Technology Newsletter

 

Aug. 4, 2020

 

As an industry that is being significantly impacted from the ramifications of COVID-19, it is important to gauge the opportunities in front of us and how we can differentiate our businesses moving forward. Our top priority is to do everything we can to help our members and the lighting industry remain healthy, both in body and business.

 

 

Terry McGowan, FIES, LC

Director, Engineering & Technology

 

 

Newsletter Sponsor:

UVC germicidal devices:

What consumers need to know

 

A warning/position paper titled "Ultraviolet-C (UVC) germicidal devices: what consumers need to know" is being issued jointly by the ALA, NEMA and UL. It is intended to be distributed widely and used by ALA members and their customers – including retail consumers – in order to provide important information about ultraviolet-emitting lighting products that are now being sold for disinfection of rooms, surfaces, materials and objects in the home. Such UV germicidal products may or may not be effective and can cause damage to eyes and skin as well as to house plants, pets and a variety of materials used for home furnishings and decorations.

 

To view the position paper, go to the ALA website at GUVSafety.com.

 

 

I’ve added the following technical points because they are particularly important to those who are involved in residential lighting and who are also working to properly understand and apply UV germicidal products in the home. We expect new products to be developed including stand-alone UV fixtures and fixtures with conventional as well as UV germicidal lighting built into them. New types of ceiling fans might also offer disinfection for individual rooms as well as large social spaces in commercial, hospitality, and retirement facilities. 

  • The COVID-19 virus can only be destroyed by directly exposing it to ultraviolet light in the UVC part of the spectrum which ranges from 200-280 nanometers (nm). Other UV wavelengths in the UVA and UVB parts of the spectrum are not effective against COVID-19.
  • LEDs that generate UVC radiation are in development, but currently expensive and not generally available for today’s germicidal products. The disinfection products now being sold use gas discharge tubes which look like small fluorescent tubes with no phosphor coating. This UVC germ-killing technology has been in use safely and successfully for more than 70 years.
 

 

  • Disinfection = (UVC Intensity) X (Exposure Time). So it is difficult to determine if any portable UV product, such as an ultraviolet wand, is effective if it is just moved around randomly near objects and surfaces. Direct exposure is also required. UVC light reflected from most surfaces does not destroy germs. UVC is not visible to the human eye, but the light sources that generate it typically generate a small amount of visible blue light.

 

  • Effective and safe UVC disinfection products that can be used in homes include UVC lamp assemblies built into HVAC ducts and permanently mounted wall and ceiling fixtures that direct their UVC light toward the ceiling and are positioned so that no direct light reaches room occupants or sensitive surfaces and materials.

There is a growing demand and opportunity for new residential lighting fixtures and ceiling fan products that are designed to disinfect room air while preventing direct exposure of people and furnishings to the UVC emissions.

 
  • UVC germicidal products can be tested and certified for fire and electrical safety using existing UL and CSA standards such as UL1598 (Luminaires). However, there is no product certification and testing process for germicidal effectiveness or human safety from germicidal UV exposure.

 

  • There is a growing demand and opportunity for new residential lighting fixtures and ceiling fan products that are designed to disinfect room air while preventing direct exposure of people and furnishings to the UVC emissions. This opportunity will be explored during the upcoming ALA Virtual Symposium, Sept. 14-16, 2020.
 
 

Engineering/Technology News

  • Information about germicidal lighting from Intertek. Order a Fact Sheet here.
  • A new website, Lighting For Healthy Living, builds upon the years of light and health research done by the Lighting Research Center. The site includes sections on research, education and applications where quantitative lighting designs can be developed.
  • TÜV SÜD has put together a global compendium of energy-efficient lighting regulations and programs for lighting products. If you sell products outside of the U.S., this is a good reference to the requirements (voluntary and mandated) that those lighting products must meet. You may download the white paper here.

 

Thank you for your interest (and feedback) regarding our UV germicidal efforts. There is much more to learn about the subject and your suggestions are welcome.

 

Sincerely,

 

 

Terry McGowan, FIES, LC

Dir. of Engineering & Technology

American Lighting Association

tkmcgowan@att.net



 

 

 
 
 

 

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