by Stephen Lawson, COO of Aseptic Health
Ultraviolet C light (UVC) has been around for years, with claims that it prevents the spread of germs. Does it work? Is it safe? Is it corrosive? To shed light on the subject, we’ve compiled a few notes and opinions from some trusted resources to reach a conclusion.
Is Ultraviolet C Light Safe?
In an article titled “UV Lights and Lamps: Ultraviolet-C Radiation, Disinfection, and Coronavirus,” published in August, 2020 by FDA.gov, we read that there are safety risks with UVC lamps.
- Direct exposure of skin and eyes to UVC radiation from some lamps may cause painful eye or skin injury. You should never look directly at a UVC lamp source.
- Some UVC lamps generate ozone. Ozone can be harmful to your lungs.
- Other UVC lamps can contain mercury which is highly toxic. Extreme care should be taken in cleaning up and disposing of a broken lamp.
- UVC can degrade certain materials: plastics, dyed textiles, and polymers such as nylon, Teflon, silk and wool.
But is UVC effective against viruses and bacterium?
According to the FDA, UVC light can effectively inactivate germs on hard surfaces, but not always. And they do not work on porous surfaces.
To eliminate viruses and bacterium, the germs must be directly exposed to the UVC light. If the germs are covered by dust, soil, biofilms or embedded in porous surfaces or the underside of a surface, they will not be inactivated.
Are Home UVC Lights Effective?
A quick stroll through Amazon.com reveals dozens and dozens of UVC Lights for home use. Prices range from under $20 to hundreds of dollars.
According to a May, 2020 interview on WebMD Health News, the devices aren’t regulated for home use. “They haven’t been studied sufficiently by scientists,” says Charles Gerba, PhD, a microbiologist and professor at the University of Arizona.
“If someone were to ask me whether they should invest in a home UV light, I wouldn’t do it right now,” Gerba says. “There’s just not enough data on them, and there’s a lot of room for user error.”
Many industries are currently using UVC lights for disinfection including hospitals, aerospace, transportation and water purification.
Hospitals have been safely using UVC light for years in operating rooms after hours when there are no people in the room. According to a study published in The American Journal of Infection Control and reported in Medical News Today the technology eliminates up to 97.7 percent of pathogens.
To learn more about kill logs, read this DisinfecTip. You’ll discover that 97.7% is not a lot of killing power.
The article goes on to say that UVC light will not replace manual cleaning and disinfection with chemicals.
What About UV Light In HVACs?
UVC lights made for HVAC coils and air handlers are installed to eliminate many types of fungi, bacteria and viruses. There are pros and cons.
The best systems are costly and the lights must be replaced every 12 to 24 months. In addition, the surrounding temperature and humidity levels of the home or building and reflectivity of surrounding surfaces will also have an impact.
And when it gets right down to those kill logs (how effectively the lights are killing) the number is around 99%. Even though that sounds like a lot because it’s close to 100%, that’s not how kill logs work. If the lights were killing ALL of the germs on the coil and the air handlers the number would be 99.99999%.
How We Measure
At Aseptic Health we are always looking for innovations in cleaning technology. We created the Certified Clinically Clean® designation to identify those products, practices and protocols that meet certain standards for safety and effectiveness.
At this time we do not have evidence that Ultraviolet light technology is safe for general use as a disinfectant.