Can HEPA Filters Protect You from COVID-19?
Governor Cuomo of New York announced earlier this month that malls could not open without a HEPA filter in place.
When the news was received by an environmental health researcher at Harvard University, Joseph Gardner Allen, he was overjoyed. Gardner said “I’ve been writing consistently since early February about how healthy buildings should be the first line of defense against the novel coronavirus. Allen added that “buildings are not putting in appropriate control measures.”
Allen is concerned about the current guidance in place that focuses primarily on hand washing, social distancing, and droplet precautions. Concerned about the lack of focus on the role of indoor air and the spread of SARS-CoV-2, Allen was one of 239 scientists that wrote a letter to the World Health Organization (WHO) and the US Centers for Disease Control and Prevention (CDC), asking for them to expand their guidance on how the virus is spread through airborne means.
Currently, an aerosolized mode of transmission is not being publicized because “they don’t want to talk about airborne transmission because that is going to make people afraid,” co-author Donald Milton, a University of Maryland professor stated.
According to the CNN article “On Thursday, WHO released a new scientific report that acknowledged the virus could possibly be spread through the air in crowded indoor spaces. The international public health agency had always recognized that SARS-CoV-2 could be spread during surgeries and other aerosol generating procedures.”
The organization went on to state that outbreaks of the virus have been connected to indoor settings where people may be shouting, talking, singing, or even just being present for an extended period of time. This connection suggests an airborne route in the form of droplets.
To battle the airborne mode of transmission, HEPA air filters play a key role. At their worst, HEPA filters are 99.97% efficient at removing airborne particles equal to, smaller or larger than 0.3 microns. However, at ISO-Aire™, our HEPA filters are 99.99% effective, making them a sound investment for protecting your indoor space. SARS-CoV-2 is believed to be between 0.6 to 1.4 microns. According to Allen, “filters are rated at their worst performance, so 99.97% is the worst it will do. And that’s rated for a particle size of 0.3 microns, but smaller and larger it actually does better. So the point is that it’s capturing nearly all particles.”
If a business has the resources, a HEPA filter can be combined with other technologies such as germicidal UVC light which will help to destroy germs suspended in the air as it passes through the HVAC system.
Allen agrees that combining other technologies with a HEPA could be most beneficial. "No one strategy alone is going to work. But if we layer enough of these on top of each other, we can significantly reduce risks."