With global concerns over the spread of coronavirus, many consumers are looking for ways to protect themselves and their families and to stay healthy. The Center for Disease Control and Prevention (CDC) has published information on how the virus spreads, and measures individuals can take to protect themselves from being exposed to the virus, including frequent hand washing, practicing social distancing, wearing face masks when out in public, and cleaning and disinfecting frequently touched surfaces daily. However, many consumers have begun searching for additional solutions for reducing their exposure to COVID-19 while at home, such as whether the ultraviolet (UV) light on home air purifiers offers any added protection against coronavirus.
This guide provides an overview of what a UV light air purifier is and how it works, as well as what experts are saying about their effect on coronavirus.
What is a UV light air purifier?
The innovation of UV air purifiers provides another option for consumers to improve the air quality of their indoor spaces. These devices feature technology that substantially removes the air’s harmful microbial particles — effectively killing these microbes and particles without the use of filtration. Instead, ultraviolet rays destroy them as they pass through the unit.
UV air purifiers, or UV-C light air purifiers, use short-wave ultraviolet light to deactivate airborne microorganisms and pathogens, including bacteria, mold and viruses. These devices have the same goal as every other air purifier, which is to reduce indoor air pollutants. You might also see this technology referred to as UV germicidal irradiation or UVGI.
When air moves through the unit, it must pass by UV lamps. In doing so, those lamps attempt to disinfect the air using germicidal irradiation.
One of the biggest safety concerns about UV light air purifiers is that during the disinfecting process they can produce ozone which, when inhaled, poses significant health risks to animals and humans. Despite UV-C light air purifiers being available as standalone units, this is rare. The main reason is, for full effectiveness, they often require additional systems, like a particulate filtration system. They can also be purchased as an add-on that can be installed directly into your HVAC system.
Using UV light for disinfecting objects and surfaces
The sun, as well as special lamps, produces ultraviolet (UV) light. UVA, UVB and UVC are the three different types of UV light. Of the three, UVC has the most energy. UVC works for disinfecting, because its energy destroys microbes, including the genetic material in viruses.
The main disinfecting power of UV air purifiers is its UV-C light. The high concentration of energy in the UV-C light allows these units to:
Before purchasing a UV light air purifier, read the product’s packaging to ensure the air purifier is using UV-C light. The UV air purifier product packaging should also include information regarding its effectiveness against harmful pathogens, including:
- How long the pathogens have exposure to the UV-C light
- The intensity of the UV-C light when killing pathogens
- The pathogen’s proximity to the light as it passes through the air filter
- How often the air circulates through the UV air filter
Can UV light air purifiers help protect against coronavirus?
Experts go back and forth regarding this question, so the best answer is, “maybe.” Let’s look at what the experts are saying:
Experts supporting the claim
The International Ultraviolet Association (IUVA) supports the claim that UV light air purifiers could play a role in reducing the transmission of coronavirus. According to Dr. Ron Hofmann, President of the IUVA and a professor at the University of Toronto, a team of experts was assembled by the IUVA to develop guidelines for using UV light technology to disinfect and help prevent coronavirus.
The director of the Center for Radiological Research at New Your City’s Columbia University, David Brenner, believes that UV-C light could reduce viral exposure and speed sterilization. And Andrea Martin Armani, an expert in light and biology, says the UV light in air purifiers helps destroy viruses, as well as the ability for bacteria to replicate.
Experts questioning the claim
The National Academies of Sciences Engineering Medicine has reported that UV light could kill COVID-19. They made this statement because, in the past, UV light has been effective at destroying other forms of coronavirus. Therefore, there’s some possibility it could work on the novel coronavirus.
The Food and Drug Administration (FDA) has also stated that many UV light devices might be adequate as a secondary disinfecting device in health care settings. These devices use UV light radiation in air purifiers to help reduce the risk of patient exposure to COVID-19.
Despite these claims, the Environmental Protection Agency (EPA) does not agree. Instead, the EPA defines a UV light air purifier as one that destroys, traps, mitigates or repels pests, which does include bacteria and viruses, but these devices are not on List N, which includes disinfectants that are registered by the EPA.
The country’s Federal Insecticide, Fungicide and Rodenticide Act (FIFRA) sets the regulatory requirements for pesticidal devices. So, even though the EPA does not register these devices, they have regulatory requirements, including reporting and labeling requirements. That means the FIFRA prohibits the distribution or sale of pesticidal devices that do not feature proper branding, such as the pesticidal device’s labeling featuring misleading or false claims. Those who sell these devices containing claims that are misleading or false could face penalties under FIFRA.
List N contains products meeting the EPA’s criteria regarding fighting against the virus that causes COVID-19, which is SARS-CoV-2. The surface disinfectant products the EPA approves for List N do not have any testing backing their ability to fight against SARS-CoV-2. However, the EPA expects them to work mainly because:
- They are effective against harder-to-kill viruses
- They were effective on other forms of coronavirus that are similar to SARS-Cov-2
The Guidelines for Environmental Infectious Control in Health Care Facilities show the CDC recommending UV light to supplement hospital infection control methods. The CDC also recommends using UV light in homeless shelters to reduce the spread of tuberculosis. And, while there is guidance from the CDC regarding cleaning and disinfecting surfaces against COVID-19, there is no indication of the use of UV light air filters. Instead, the CDC refers to the EPA’s List N for guidance regarding the approved disinfectant products.
We need to learn more
In hospitals, we know that UV-C light destroys microbes, including viruses. Despite that fact, hospitals and other health care facilities rarely disinfect using UV-C light. The main reason is that the UV technology industry and the U.S. government are still defining standards regarding these technologies for use in hospital settings. Therefore, when you are trying to figure out whether or not a UV light purifier helps protect against coronavirus, there is no absolute “yes” or “no” answer. While many experts agree that the UV light in these air purifiers is effective for preventing viruses from replicating, there are still a lot of other experts who believe this technology is not sufficient for preventing the spread of coronavirus.