Since the spread of Coronavirus (COVID-19) caused offices, stores, restaurants, and hotels to shut down across the globe, there has been increased interest in a decades-old technology that kills bacteria and inactivates viruses: ultraviolet light.
Ultraviolet light refers to short-wavelength ultraviolet radiant energy that has been proven to kill bacteria and inactivate viruses such as Severe Acute Respiratory Syndrome (SARS) and Middle East Respiratory Syndrome (MERS). And now it's being used to inactivate the Coronavirus and allow spaces that have been shuttered to safely reopen.
The kind of ultraviolet light that's used in germicidal light fixtures is UVC. UVC is one of three types of rays produced by the sun (visible light, ultraviolet rays, and infrared), but is blocked from reaching us by the Earth’s ozone. The wavelength of UVC is between 200 and 280 nm, and only UV lamps of this wavelength have been proven to inactivate the Coronavirus.
UVC germicidal lights are starting to see widespread use in hospitals, subways, restaurants, and virtually anywhere looking for an effective way to clean their space and bring their employees back to work.
In May, the New York City Metropolitan Transit Authority announced its plan to deploy 150 UVC devices across the NYC mass transit system in an effort to reduce the level of the virus on the subway and decrease the risk of anyone catching COVID-19.
Famed New York eatery Magnolia Bakery is employing the technology too, replacing recessed lighting with far-UVC light (a wavelength of ultraviolet light that, in low doses, can kill viruses and bacteria without causing harm to humans) and installing "cleanse portals" for customers to walk through before entering the establishment.
More effective for containing the spread of Coronavirus, however, is the use of UVC light fixtures to sanitize the air in a space. As we now know, the Coronavirus mainly spreads from person-to-person, through airborne respiratory droplets. Cleaning the surfaces in a space is not enough to ensure that the area has been properly disinfected; the air needs to be sanitized too.
UVC air filtration devices work by pulling in air through a fan, disinfecting that air with UVC lamps that are contained and hidden from view (and therefore cannot cause harm to occupants in the room), and pushing that clean air back out again. These air filtration devices work best in conjunction with traditional cleaning methods like soap and water and antibacterial products, as well as UVC sanitation carts that disinfect surfaces.
The UVC device best suited for your space will vary depending on the size and space type. For a large open office with cubicles, a UVC air sanitation cart as well as a UVC surface disinfection cart would work best.
Proper instruction on the dangers of ultraviolet light should be given to anyone in a space where a UVC germicidal light fixture is present. UVC light can cause damage to skin and eyes if used incorrectly. But when the proper precautions are taken, it is highly effective for disinfection and is certainly on track to becoming a widely-used technology for the safe occupation of spaces.
FURTHER READING:
Does UVC Kill Coronavirus? - The National Academy of Sciences
Germicidal Ultraviolet Frequently Asked Questions - Illuminating Engineering Society
Evaluation of UVC Light-Emitting Device for Disinfection of High Touch Surfaces - International Journal of Environmental Research and Public Health