WHY HEPA FILTER ALONE MAY NOT BE EFFECTIVE

While HEPA filters remove some particulates from the air, there are many harmful contaminants in the air that aren’t particulate matter.

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Today, many are claiming that HEPA Filter will remove the virus even the coronavirus. But this may not be entirely correct. As the virus is .1 micron while HEPA filter is .3 micron, there is a greater chance that virus may not get trapped in the filter.

Even though it may get trapped, it will survive on the Filter and may get released back into the air.

Dr. Erin Sorrell, an assistant professor of microbiology and a member of the Center for Global Health Science and Security at Georgetown University, U.S., told Buzzfeed. “The filter itself is .3 microns and the virus itself is roughly .1 microns.”

In general, viruses are at least 100 times smaller than bacteria and their size would range anywhere between 0.0004 to 0.1 microns. “This means even the most powerful [HEPA] air filters would struggle to purge a virus from the air,” Patrick Hearn explains for Digital Trends.

There are many contaminants in the air which may not get removed from the HEPA (High Efficiency Particulate Air) Filter

VOCs

Volatile Organic Compounds are airborne chemicals that mostly derive from off-gassing of building materials and the most concerning health effect associated with VOCs is that some are well-known carcinogens. HEPA filters are unable to remove VOC’s as they simply are far smaller in size than what can be trapped.

VIRUSES

Much like VOCs, viruses are also too small to be removed. Despite this fact, HEPA based products were marketed for a long time with the claim to protect from viruses. The US Federal Trade Commission (FTC) has now regulated that HEPA filter based products can no longer make that claim.

BACTERIA

While bacteria are large enough to be trapped, bacteria are understood to release endotoxins into the air stream when dying on the air filter surface. Studies have demonstrated that endotoxins cause inflammatory and atopic responses in nonasthmatic and asthmatic participants.

MOLD

Mold spores are large enough to be caught in HEPA filters but stay alive on the filter surface. Other particles that accumulate and fill the filter start acting as nutrients and allow mold spores to potentially grow on and through the filter membrane and eventually release new spores into the air.