By Linda Longo

Reacting to the global focus on reducing COVID-19 infections, the lighting community as well as end-consumers are increasingly interested in the effectiveness of UV lighting products in regard to COVID-19.

On the scientific side, the Illuminating Engineering Society (IES) just released a report this week on Germicidal Ultraviolet (GUV) and how it could reduce the spread of COVID-19. The impetus for compiling the report was “the wave of seemingly conflicting statements and opinions about the disinfection capabilities and safety of GUV,” according to the organization.

In the report, the IES’ Photobiology Committee details germicidal ultraviolet (GUV) disinfection and its potential to safely reduce the transmission of SARS-CoV-2, the virus that causes COVID-19. The report’s authors have provided answers to frequently asked questions about GUV, drawing from expertise from the Centers for Disease Control and Prevention (CDC), the Food and Drug Administration (FDA), Harvard Medical School, the Icahn School of Medicine at Mount Sinai Medical Center, and from germicidal UV manufacturing and research organizations.

“The goal is to provide timely and objective information on a proven technology that can reduce the spread of this highly contagious virus,” says Brian Liebel, IES Director of Standards and Research.

The report reiterates that Germicidal UV can successfully and safely be deployed to disinfect air in occupied hospital spaces such as waiting rooms, intensive care units, and operating rooms. In unoccupied controlled-access environments, germicidal UV can be used as a supplemental measure to disinfect room surfaces to reduce the spread of healthcare associated infections. Germicidal UV is also being applied for disinfection of some personal protective equipment (PPE) for limited reuse during the pandemic. Most importantly, the report emphasizes the need for GUV to be applied correctly and monitored for output and safety, and that training on the operation and maintenance of the systems over time is essential.

Addressing the increase in consumer-oriented UV disinfecting “wands” and other products available on the open market, the committee report cautions these UV products for residential use are inadequately proven and unregulated, and therefore may pose a safety hazard, plus are unlikely to provide the protection expected.

Noting the rise in consumer interest of these UV disinfectant products, the American Lighting Association (ALA) issued guidance yesterday from its Director of Engineering & Technology Terry McGowan, FIES, LC to its lighting showroom membership.

“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,” the ALA stated in its Technology Newsletter. “Our top priority is to do everything we can to help our members and the lighting industry remain healthy, both in body and business.”

McGowan referenced the growing interest in germicidal lighting, adding that a quick look online or at manufacturers’ literature and websites shows a proliferation of germicidal lighting equipment from permanently installed luminaires to portables – including light wands and screw-in germicidal bulbs – all designed to decontaminate objects, materials, or surfaces.

When assessing whether this technology is one that should be embraced by the residential lighting industry, McGowan is unequivocal. “Yes, it’s an opportunity, but it is also more complicated than picking a lamp or luminaire out of a display or catalog; and some design work (much like lighting design) may be required. Most important of all, there are safety concerns because germicidal lighting products can cause eye and skin damage to both humans and pets. Home furnishings – including wood, plastics, and fabrics, can be damaged as well.”

To help ALA members better understand the terminology so that they can educate their customers, McGowan explains, “Germicidal UV or GUV refers to the technology of germicidal lighting, which utilizes ultra violet light sources. Technically, the GUV spectrum is defined as UV-C, which ranges from 200 to 280 nanometers (nm).”

For those confused between UV-C and UV-A, McGowan continues, “There is another band in the UV spectrum called UV-A that is also getting attention for residential germ-killing properties. The UV-A wavelength range is from 315 to 400 nm and includes what used to be known as the blacklight region of the spectrum. Traditionally, so-called BLB (blacklight blue) lamps were (and still are) sold for insect traps, and theatrical and special-effect lighting, where glow-in-the-dark effects are desired. Such lamps and lighting products have limited germ-killing power, and typically require long exposure times to be effective. According to a new report from the IES, UV-A blacklight lamps are not effective against the COVID-19 virus.”

McGowan warns, “GUV lighting in the UV-C part of the spectrum is an effective killer of COVID-19 and similar viruses, but it has to be used carefully to be both effective and safe.”

For those showroom owners interested in carrying these types of GUV products, or at least educating their customers who have asked about them, McGowan imparts these cautions:

  • Insist upon and read carefully all GUV product safety and caution notices. If none are provided, ask the manufacturer. If you feel the information provided is incomplete or hard to understand, consider not using the product.

 

  • Germicidal lighting works only via line-of-sight. Reflected light does not kill germs because most reflecting surfaces in homes absorb the critical UV-C wavelengths.
  • GUV is a good way to help control the spread of the COVID-19 virus. Learn the facts to apply it effectively and safely. Be safe and well.

 

  • Exposure matters. Exposure = Intensity x Time. Like sunburn, damage to skin and eyes results from being exposed for too long to the light source. GUV exposures, however, are likely to be measured in seconds and minutes, not hours.

If you would like more detailed information about GUV technology, the National Lighting Bureau recently posted a video featuring experts from the Lighting Research Center as well as Terry McGowan from the ALA.   The video can be accessed at: https://bit.ly/UVLRCvid