When it comes to safety concerns surrounding the use of ultraviolet to deactivate the coronavirus in occupied places, the first thing that comes to mind is the damage that UV can cause to skin and eyes.
But there’s another possible hazard: ozone emissions. Although the possibility for harmful ozone tends to be associated with UV wavelengths shorter than those that vendors are marketing for disinfection purposes, some regulators are taking nothing for granted. After all, ozone — a reactive gas consisting of three unstable oxygen atoms — can afflict the lungs and cause breathing difficulties.
Thus, the California Air Resources Board wants to make sure that the UV-C devices emerging in the fight against the SARS-CoV-2 virus are ozone safe. SARS-CoV-2 is the coronavirus that causes COVID-19.
“Air cleaners that are listed as ‘Electronic’ may be capable of generating small amounts of ozone,” CARB states on its website (CARB is the air monitoring unit of the California Environmental Protection Agency). “This category includes ionizers, electrostatic precipitators, PCOs, hydroxyl generators, devices with UV light components, and other electronic air cleaning technologies.”
CARB is testing UV products for ozone and approving those that emit less than 0.050 parts per million.
“If you find an air cleaning device for sale in California (or for sale online with delivery available to California) that does not bear the certification label and/or is not on the list of CARB-certified air cleaning devices, please contact [email protected],” CARB states.
This all came to light this week when Atlanta-based Acuity Brands announced that the EvolAIR line of UV-C troffers from its Healthcare Lighting company has passed CARB’s scrutiny.
“The California Air Resources Board (CARB) has certified that 12 models of the EvolAIR UV fixture from Healthcare Lighting have been tested to comply with the State of California’s electrical safety and ozone requirements for Indoor Air Cleaning Devices,” Acuity said in a press release.
The EvolAIR line is a ceiling troffer with air circulation mechanisms and a 254-nm mercury lamp for pathogen deactivation. It also provides room illumination with a downward-facing visible-light LED. The 254-nm lamp is enclosed in a chamber to shield it from anyone present in the room.
UV-C is the shortest wavelength band of ultraviolet radiation, ranging from 100–280 nm. It has been proven at certain wavelengths and doses to kill SARS-CoV-2. Products have emerged at 222, 254, and 265 nm. In a webcast presentation with LEDs Magazine last summer, Robert Karlicek, director of the Center for Lighting Enabled Systems & Applications (LESA) at Rensselaer Polytechnic Institute, noted that “ozone production is significant only below 200 nm.”
Up until recently, Acuity had refrained from shipping EvolAIR to California, but that has now changed with CARB’s certification.
Acuity is positioning EvolAIR not only against the coronavirus, but also in general to combat “viruses, bacteria, and fungi,” it states in a product brochure.
“EvolAIR UV and our other UV light disinfection solutions give facility managers, building owners, and other professionals an opportunity to harness the power of UV to reduce pathogens,” said Cleveland Blankenship, business unit leader with Healthcare Lighting.
Acuity is providing EvolAIR UV fixtures for drop-in grid ceilings, recessed hard ceilings, surface mount or suspended installations, with illumination options of 3000K, 3500K, 4000K, and 5000K CCT. Optional downlight canisters are also available.
Ironically, while UV-C can yield harmful ozone, it is the ozone layer in the atmosphere that filters out UV-C from sunlight and prevents it from reaching Earth and causing injury.
MARK HALPER is a contributing editor for LEDs Magazine, and an energy, technology, and business journalist ([email protected]).
*Updated Aug. 25, 2021 1:46 PM for UV lamp correction - the Acuity EvolAIR contains a mercury-lamp UV source.
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