We know that businesses across the world are being bombarded by salespeople offering the latest and greatest anti-viral tech - from sanitizing booths to HEPA filters to UV wands, there’s a lot of products out there without a lot of clear science.
Here’s what we do know:
Studies show that ultraviolet-C light can be used to kill virus particles for SARS, a similar virus to the one that causes COVID, and can be used to disinfect surfaces. Hospitals use this technology, as have some public transportation systems like the NY subways.
But there are a few caveats:
First, UVC light can be harmful for humans, so it should generally only be used when people aren’t around. It can cause burns, generate ozone which irritates airways, can degrade certain plastics and other materials, and, as if this didn’t sound dangerous enough, some UV lamps have mercury in them, which can be very harmful if the lamp breaks.
Second, UVC light has to have a direct line of sight with the virus to effectively break down the proteins that cause it to kill coronaviruses. Dust, debris, fluid or anything else in the way blocks the radiation that kills the virus. So, a UV lamp wouldn’t do a lot of good to sanitize a dirty countertop, plus would never sanitize the edges and underside of that counter, for example.
A far more effective and safe way to use UVC is inside air ducts to disinfect the air. The FDA says “this is the safest way to employ UVC radiation” because it avoids direct exposure to human skins or eyes.
There’s no question that good HEPA filters and increased ventilation do help to reduce the transmission of Coronavirus. There are plenty of studies at this point that show that the virus is airborne, and anything we can do to create airflows, increase ventilation, and filter small particles from the air is good. Investing in additional portable filters or upping your ventilation is a good idea, and one that will be increasingly important as we head into winter and see more people gathering indoors.
Cold fogging, or having an outside service come in to spray down your business, can be an effective tool after cleaning (remember -- cleaning and sanitizing are two totally different things!). But as soon as employees and customers walk back in the door, they are bringing their dirty hands, breath, viruses and bacteria right back into your building, so it’s really just a snapshot in time that you’ll be 100% sanitized. This can be useful, however, after you’ve had a known positive COVID case on site. It’s also a concrete action that makes employees and guests feel safer after a positive case.
Be sure that the cleaning service is using safe and EPA-approved sanitizers, but remember that all of the approved sanitizers to kill COVID-19 specifically are applied by spray or wipe, so anything you’re fogging with is likely approved to kill other viruses like the Flu - still, it’s reasonable to assume they are effective, but should be used in addition to a thorough cleaning and sanitizing with EPA-approved sanitizers that specifically are listed as killing SARS-CoV-2, the virus that causes COVID-19..
Sanitizing tunnels are specifically not recommended by the CDC because there’s no evidence that they’re effective and the chemicals used in them can be harmful to skin, eyes, and lungs - yikes...
UVA and UVB have varying effectiveness for killing viruses, and are more harmful to humans, and should generally be avoided. Far-UVC is a newer technology that may be less harmful for human skin and eyes, but is still in the very early stages of research and isn’t known whether it’s fully effective.
Other solutions we’ve seen advertised are even less researched, like ultrasonic waves and LED blue light. These have very little research out there right now, and almost no regulation.
According to Penn Medicine, “the safety and efficacy of many UV light devices sold to the public are not routinely reviewed, so these should be used with caution.” UV radiation, LED blue light, ultrasonic waves, and all sorts of other solutions are being touted as cure-alls but need to be approached with caution and a healthy dose of skepticism.
What we know works safely are good ventilation and filtration systems, and UVC light in the air ducts to sanitize in conjunction with a strong air filter. Any other solutions range from unproven against COVID-19 to dangerous.
When buying a product, read reviews, check for a manual that includes careful instructions (including duration and dose for UV lights), and if possible, spring for something that is used in healthcare settings.
Air purification, UV lamps, and sanitizing surfaces are all good methods to help reduce the risk of transmission of COVID-19. But they are only part of the battle against the spread. They don’t account for person-to-person transmission. The best HEPA filter or UV lamps in the world won’t be any match for the large droplets that may spew from someone’s mouth as they cough or speak. Wearing a mask and washing hands often are still crucial in preventing the transmission of the virus, as is maintaining 6ft of distance and avoiding large gatherings.
We should not have a false sense of security from these high-tech mitigators, and should still focus on social distancing, mask wearing, hand washing, and staying home when sick as our best defenses.