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How Do True HEPA Filters Compare to HEPA?

What is a true HEPA filter? Is it a marketing ploy created by manufacturers or a way of distinguishing real HEPA from fakes? Let’s find out.

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true HEPA filter

When looking for air filters, you’ve probably stumbled upon those with the acronym HEPA, which stands for high efficiency particulate air, on the label. A HEPA filter is both pleated and mechanical. These terms refer to its design and filtration type, respectively. By definition, HEPA filters remove 99.97% of particles that are 0.3 microns in size. That’s pretty incredible!

In your search for air filters, you may have also come across one that claimed to be a true HEPA filter. What does this mean? Are true HEPA filters better than HEPA filters, or vice versa? Are they the same product with different labels? Have no fear homeowners! We will examine the similarities and differences between HEPA filters, true HEPA filters and some of the other jargon surrounding HEPA level filtration.

Is There a Difference Between HEPA and True HEPA?

As aforementioned, HEPA filters remove 99.97% of particles that are 0.3 microns in size. That is to say that these filters must remove a minimum of 99.97% of particles at the 0.3-micron size to be considered HEPA level filtration. A filter with this removal efficiency is a HEPA filter.

Home Air Filter: Do you need a HEPA filter as your whole-home air filter? Actually, no. HEPA filters are so effective that they limit airflow in the average residential system. Learn more →

Confusion among HEPA terms comes down to the gap in official certification between government/military-use HEPA filters and commercial use products. The Department of Energy (DOE) holds HEPA air filters to a standard (as they should). However, DOE verification is not available for consumer products. Rather, DOE approval is reserved for government and military use.

Likewise, according to the Environmental Protection Agency:

While the HEPA-designated home air filters usually perform at high levels comparable to a MERV 16, there is no widely accepted definition of HEPA performance in consumer products. Thus, they are unlikely to be equivalent in performance to HEPA-designated filter systems used in healthcare buildings and industrial processes, but still have very high removal efficiency (i.e., usually 99% or higher) for the reported particle sizes tested.


Because manufacturers producing commercial products and residential air filters cannot obtain DOE approval, they turn instead to industry-standard testing and independent certification.

It’s in this gap of official certification and testing that various HEPA terms and technical language, including true HEPA, emerged.

Are There Fake HEPA Filters?

In short, yes, there are fake HEPA filters. However, it’s a bit more complex than you might think. Let’s take a look at the types of air filters that claim to provide HEPA level filtration. 

HEPA Type & HEPA Like

Filters with the label HEPA Type or HEPA Like are absolutely untrustworthy. This is a marketing term used by manufacturers. They may or may not perform at the same level as HEPA filters. There is no way to know for sure and they do not conform to any standard. 


There is a particular company that uses the marketing term UltraHEPA. They claim that their air filter “removes particles 100 times smaller than HEPA standard.” In other words, their air filter can capture particles as small as 0.003 microns in size. This is highly unlikely for a residential air filter. 

Permanent HEPA

Permanent HEPA filters are washable (enough said). Washing a HEPA filter damages it, reducing its effectiveness over time. HEPA filters cannot be washable or reusable.


HEPASilent air filters are not necessarily fake, but they are different. They use an electromagnetic charge to capture particles. Whether or not this technology is more effective, it is not real HEPA.


Some manufacturers use the term true HEPA to convey that their HEPA filters conform to the DOE standard even though they cannot undergo DOE-level certification. While others use true HEPA as nothing more than a marketing ploy.

Absolute HEPA

Absolute HEPA is a term often used interchangeably with true HEPA. The only difference between the two is the fact that absolute HEPA filters claim to remove more than 99.97% (but less than 100%) of particles that are 0.3 microns in size. The bottom line is, if a filter reaches the 99.97% threshold, then it is HEPA level filtration, regardless of the term applied.

Third-Party Verification: Air filters aren’t the only solution where data testing matters. Standardized testing, data verification and product certifications are also crucial in regard to air purifiers. Read more →

All this said it’s best to invest in air filters with verified HEPA level filtration. And, in the end, homeowners must trust that manufacturers have tested these filters and confirmed that they are in compliance with the DOE’s standard. This means clear available testing information, independent verification or certification documentation and HEPA labeling on the product. It’s important to look for the numbers 99.97% and 0.3 microns on the label. If an air filter does not have these terms and numbers on the label, run in the opposite direction. 

What Can HEPA Air Cleaners Do To Help Prevent COVID-19?

Recently, Columbia News interviewed Faye McNeill, a chemical engineering professor at Columbia University who studies aerosols. When asked if HEPA filters can capture COVID-19 particles, McNeill explained,

So yes, HEPA filters can catch particles that contain coronaviruses. People expel droplets of respiratory fluid, saliva and possibly viruses into the air when breathing, coughing and talking. Even if the water in the droplet evaporates, the droplets contain salts, proteins and other material in addition to any virus, which means the remaining particles are typically a few microns in size, making them fairly easy to trap with a HEPA filter.

Real HEPA filters conform to the 99.97% standard, regardless of particle or contaminant. Whether virus aerosols or particulate matter, HEPA filters capture and remove particles.

True HEPA Filters Are Worth It 

Are true, real, verifiable HEPA filters worth your while as a homeowner? Absolutely! They capture dust, dander, pollen, mold and many other air pollutants. This is extremely beneficial for those with allergies, asthma, other respiratory illnesses and those looking to stay healthy. Also, keep in mind that HEPA filters are too much filtration for most home HVAC systems. HEPA filters really benefit indoor spaces as additional add-on solutions such as a portable HEPA air purifier! Remember homeowners, beware of fake HEPA terms and claims! 

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