As we mark the first anniversary of the COVID-19 pandemic, we’re still figuring out the delicate balance between reopening and transmission control. This pandemic has been a learning experience for us all, exposing just how important indoor air quality is for the health and safety of everyone. As part of this learning process, new and existing pieces of technology have been widely adopted to limit the spread of COVID-19.
Bipolar ionization, already prevalent in medical settings, emerged as one of the most promising remedies for the airborne and droplet transmission of COVID-19. But how does this air purification method stop viruses? Are there any downsides to bipolar ionization? Is bipolar ionization safe? We’d like to take this article to discuss these concerns.
Before we can address the potential benefits of bipolar ionization technology for dealing with COVID-19, we must understand how it works.
As the name implies, bipolar ionization works by introducing positive and negative ions to the air, which then react with other substances for air cleaning and sanitation purposes. When molecules in the air, like water vapor, are energized, often through electrical discharges, the molecules will split into ions. In the case of water vapor, the molecules split into positive hydrogen ions (H+) and negative hydroxide ions (OH-). Once these ions enter the air, they react with other substances in various ways.
In theory, bipolar ionization can have air cleaning benefits that eliminate viruses and help settle airborne droplets and virus-laden particles.
As we mentioned before, bipolar ionization technology produces hydroxyl ions. These particular ions strip away hydrogen atoms from the proteins on the virus’s capsid, the outer layer of protection that the virus uses to engage with the environment. By removing the hydrogen atoms, the proteins’ configuration changes, and the virus can no longer infect other cells to replicate. You can think of it as changing the shape of a key; after the change, it obviously won’t accomplish the same function.
Beyond the virus itself, ions also help settle airborne particles. Ions, because of their charge, will be attracted to larger molecules and stick to them, effectively weighing them down. The airborne particles will settle on surfaces more quickly, where they can be disinfected directly, or be removed through air filtration.
Before we give bipolar ionization the green light, we have two remaining questions: is bipolar ionization safe, and is it effective? After all, other consumer ionizers have been linked to ozone, a significant health threat for building occupants, and most of our previous discussion was theoretical.
To answer the first question, ASHRAE still considers bipolar ionization an “emerging technology” and notes that the performance and safety of these devices will vary by manufacturer. Because there are no large-scale studies about the safety of these ionizers, you need to consider the ozone production and product test reports from the individual manufacturer carefully. Before investing in a bipolar ionization system, be sure that it has a UL 2998 certification, which validates zero ozone emissions claims.
Regarding the efficacy of bipolar ionization systems, the answer is quite similar. The technology has significantly matured from its introduction in the 1970s, and the effectiveness of bipolar ionization has increased along with its safety. There isn’t a large body of evidence for the efficacy of bipolar ionization on SARS-CoV-2 (this is normal, as the virus is relatively new), but a growing number of manufacturer reports from sources like AtmosAir suggest that bipolar ionization successfully cuts down the transmission of an array of illnesses, including SARS and COVID-19. We offer the same recommendation: carefully inspect performance data from the manufacturer.
Air purification methods like bipolar ionization are just one part of a COVID-19 prevention strategy. Other practices, like increased ventilation, humidity optimization, and indoor air quality monitoring, play essential roles in stopping the virus. For more information about these methods and how to craft a comprehensive reopening plan, read more below: