A portable UVC lamp for disinfecting my home
SUNLIGHT streams through the bay window at home, making it the perfect spot to disinfect mail or packages delivered at home. Studies have shown that the coronavirus disease 2019 ( Covid- 19) can be transmitted through fomites, droplets and aerosols. Transmission through fomites can be reduced with the washing of hands and disinfecting of objects. At a designated table, I spray or wipe the items I shopped for or were delivered with a disinfectant solution. With the rainy season, minimal sunlight would be available to disinfect my other items, so the idea of an ultraviolet- C ( UVC) lamp came to me.
The question is, can UVC light inactivate the severe acute respiratory syndrome coronavirus 2 ( SARS- CoV- 2) that causes Covid- 19?
United States Food and Drug Administration ( FDA) said, “UVC radiation is a known disinfectant for air, water and nonporous surfaces. UVC radiation has been used for decades to reduce the spread of bacteria such as tuberculosis. For this reason, UVC lamps are often called germicidal lamps.”
Studies published on both SARS and the Middle East respiratory syndrome at the National Institute of Medicine ( pubmed. ncbi. nlm. nih. gov) show that UV light could inactivate the viruses, so it’s possible that it might have a similar effect on SARS- CoV- 2. The conclusion in the “Stability of SARS coronavirus in human specimens and environment and its sensitivity to heating and UV irradiation” research in September 2003 is that “heating and UV irradiation could efficiently eliminate the viral infectivity.”
The effectiveness of UVC lamps in inactivating the SARS- CoV- 2 virus is unknown because “there is limited published data about the wavelength, dose, and duration of UVC radiation,” added the US FDA. Despite the lack of data, people like myself are buying UV devices to combat the virus. Lazada and Shopee offer not just UVC lamps, but also UVC wands and UVC boxes to disinfect medical equipment, surgical masks and even cellphones.
“Lamps may emit very specific UVC wavelengths ( like 254 or 222 nanometers or nm) or they may emit a broad range of UV wavelengths,” according to the US
FDA website.
The conventional 254- nm germicidal table lamp is the one I purchased from Prolabsph. com. One day, I hope to get hold of the Excimer lamp or Far- UVC lamp ( 207 to 222 nm), which can “inactivate bacteria without harm to exposed mammalian skin,” according to the Scientific Reports Volume 8, Article number: 2752 published in Nature. com.
When I talked to the supplier, he discussed the product’s health and safety risks. Hensaid the germicidal lamps do not cause any permanent damage, but precaution is highly recommended. Direct exposure of skin and eyes may cause painful eye injury and burn- like skin reactions. Never look directly at a UVC lamp source, even briefly. Features of the 38- watt UVC lamp include a built- in timer, remote logic control system, dual wave for full sanitation with the UV + 02 wavelength technology. A 20- square- meter ( m2) room requires 15 minutes UVC light exposure, while a 40- m2 room would need 40 minutes. Make sure that no person, pet or plants are present inside the room before you sanitize with the UVC light. After the timer goes off, one needs to wait for another 30 minutes before entering the room to get rid of the residual odor after disinfection, otherwise known as volatile organic compounds.
I disinfect items with the UVC lamp in a 20- m2 room for 15 minutes. The US FDA explains the limitations to how e f f e c t i ve UVC radiation could be at inactivating viruses.
“It is important to recognize that, generally, UVC could not inactivate a virus or bacterium if it is not exposed to UVC. In other words, the virus or bacterium would not be inactivated if it is covered by dust or soil, embedded in a porous surface or on the underside of a surface,” it said.
I assume that even items inside a bag need to be exposed for disinfection. It is one reason I still wipe the items with disinfectant solution. The UVC radiation is just another layer of protection inside my home besides cleaning and using our Plasma Air Purifier.