HEPA Filtration 101

Share this article

By Ken Lee, Director, Global Product Standards at BISSELL®

There’s a lot of science behind what a breath of fresh air can do for your mental health, and the last thing you want to worry about when taking that breath is whether the air you’re breathing is clean or not. HEPA, an acronym for High-Efficiency Particulate Air, filtration technology helps to ease many of those worried minds and is used in several BISSELL products.

HEPA Filtration 101

What is HEPA technology?

According to the U.S Environmental Protection Agency (EPA), in order to be classified as HEPA, a filter must remove at least 99.97% of dust, pollen, mold, bacteria, and other airborne particles that are 0.3 microns and larger. To put that size into perspective, a typical hair strand width is between 50-100 microns! It’s safe to say 0.3 microns is very small.

HEPA Filtration 101 Infographic

How are HEPA filters tested?

Scientists in the U.S. military and nuclear industries set the test standard for HEPA filters over a half a century ago. The military needed filters to protect troops against potential chemical and biological warfare during WWI and WWII. And the nuclear industry needed filters to protect scientists from lethal radioactive particles while they developed a nuclear bomb under the Manhattan Project during WWII. Through their research to construct filters that would meet their needs, they discovered that the most difficult particle sizes for high-efficiency filters to capture were approximately 0.3 microns in diameter, which became defined as the Most Penetrating Particle Size (MPPS). These same scientists defined the minimum efficiency of a true HEPA filter to be no less than 99.97% when tested at the MPPS (i.e. - 0.3 microns).

But that standard doesn’t fully paint the picture of just how efficient HEPA filters are. In fact, these filters have an even greater efficiency in capturing particles that are both larger and smaller than that 0.3 standard. If you take a look at the graph below, you’ll see that as the particle size moves above or below 0.3 microns, the filtration efficiency of a HEPA filter actually improves beyond 99.97%.

I think it’s important to show this graph to help paint a picture for consumers about just how fantastic HEPA filters are.

CDC HEPA Filtration Graphic

How do HEPA filters work?

HEPA filters are constructed of a labyrinth of layered fibers which creates a torturous path for the dust-laden air to pass through. HEPA filters work to capture particles in three ways.

  • The larger particles are captured by the filter fibers through a sieving process as they pass through.
  • The mid- to smaller-size particles collide and stick to the individual filter fibers due to the torturous path they are forced to pass through.
  • The smallest particles either collide and stick to the filter fibers or collide with the other larger particles already captured by the filter fibers.

What can a HEPA filter capture?

HEPA filters capture airborne particles at an efficiency of at least 99.97%. This means HEPA filters can capture extremely small particles such as pollen, smoke, spores, pet dander, dust, and even bacteria. Most particles of that small size can evade standard air filters.

How does BISSELL use HEPA filtration technology?

We are no stranger to the benefits of HEPA at BISSELL. In fact, we have several products built with HEPA technology, including two HEPA filter vacuums and three HEPA filter air purifiers. Two of our top-rated vacuums, MultiClean Allergen Pet, and MultiClean Allergen Lift-Off® Pet, are engineered with HEPA technology and are a great option to trap dust and allergens while you clean.

Our line of air purifiers have HEPA filters, too. BISSELL air400, air320, air220 all have three stages of filtration, with a pre-filter, an activated carbon filter and a HEPA air filter. The three-stage system works by works by trapping large particles in the pre-filter, smaller particles in the HEPA filter and odors in the carbon filter.

We understand that your home is your safe space, and you want to be using the best possible products to clean the surfaces and the air you breathe. That’s why we’re so passionate about recommending products with HEPA filters be added to your home. For even more information on the benefits of our products, be sure to check out this post on how BISSELL HEPA filter air purifiers and HEPA filter vacuum cleaners work together to clean your space.

About Ken: Ken Lee has over 35 years of product testing and performance standards development experience in the floorcare cleaning industry. He holds a Mechanical Engineering degree from Miami University and a Masters degree in Engineering Management from Western Michigan University. In his role at BISSELL, Ken is a leader in the development of industry standards in both Europe and the U.S. He is also responsible for ensuring BISSELL’s advertised claims are consumer relevant and scientifically sound and defensible.