How Is Molekule’s PECO Different From HEPA Air Purifiers?

Healthy air is invisible, and so are the unhealthy chemicals and microbes floating around in it. So what is a way we can know if the air purifiers we run in our homes are keeping our air healthy? We can learn about the technologies that each one uses.

Here we are going to discuss two types of air filtration solutions currently available. One is HEPA filtration, ubiquitously available in hardware stores and the industry standard for 70 years. Molekule is a newcomer to the market that contains proprietary Photo Electrochemical Oxidation or PECO technology.

What are HEPA and PECO?

The first three letters of HEPA stand for High, Efficiency, and Particulate. Depending on who you ask, that “A” could stand for Air, or Absorber, or Arrestance.

No matter which word you chose, HEPA refers to a fine net-like arrangement of very thin fibers that halt the movement of particles blown through the filter by a fan. The standard HEPA filter is a fabric that acts a lot like a net to remove pollutants from the air. It is not a net, but basically tiny unhealthy particles of matter in the air become trapped in or on the fibers, or media, of the HEPA filter, and clean air is allowed to pass. The pollutants remain lodged there due to a combination of friction, being electrostatically attracted to the fibers, and the pressure of the fan. So HEPA filters end up with a dense concentration of pollutants caught in the fibers.

HEPA filters are typically rated with an efficiency rating, which is a percent chance of how well they can capture particles that are 0.3 microns. This is the size of a test particle that can most easily penetrate a HEPA filter. HEPA manufacturers use salt for their test particles, but particles in the real world are very different than free-floating salt. Thus this standard does not accurately reflect how HEPA typically works in the home. It’s not known exactly how small a particle has to be to pass through a HEPA filter 100% of the time, but toluene, a volatile organic chemical (VOC) which is on the order of .0005 microns, will bypass a HEPA filter completely. Similarly, all VOCs we normally find indoors will pass through a HEPA filter completely. In addition, due to their small size viruses can also penetrate a HEPA filter.

PECO stands for Photo Electrochemical Oxidation. While PECO technology is a filter, it works very differently from HEPA. It’s not like a net for simple gathering and concentration. Instead, Molekule employs a two-step process to completely destroy airborne pollutants. First, the purifier blows air through two filters: a small Pre-Filter with some carbon and a larger nanocatalyst-coated PECO-Filter. The Pre-Filter halts the movement of large particles like hair and textile fibers, and the PECO-Filter halts anything smaller. Second, the nanocatalyst on the PECO-Filter chemically converts organic substances into harmless components of the atmosphere such as small amounts of water and carbon dioxide. This process is more like a pool skimmer that vaporizes any leaves it touches instead of just collecting them for later disposal.

Differences between HEPA and PECO filtered air

As mentioned above, HEPA filters stop individual particles from floating through the air. The physics of that filtration is more complex than simply halting all particles that are too large to fit between the individual strands of the filter, but the results are the same.

Molekule’s combination of pre-filter and PECO-Filter operates completely differently. While the pre-filter halts the movement of very large particles like hair, the nanocatalyst on the PECO-Filter operates at the molecular level to chemically destroy pollutants that pass the Pre-Filter.

The primary difference is that Molekule reacts with the smallest possible building blocks of matter and HEPA filters collect pollutants down to a certain size in a net of fibers. This results in two drawbacks for HEPA when compared to PECO. The first is that HEPA cannot trap the pollutants that have very small structures, such as poisonous gases. Gases like formaldehyde and ozone simply do not stick to the fibers. The second is that HEPA cannot chemically destroy pollutants, allowing mold and bacteria to grow in the filter. If enough food (dust) and water is present, these infectious microbes can form colonies and even release spores through the HEPA filter and back into the room. Any dead mold spores or bacteria on HEPA filters disintegrate and release endotoxins and proteins that pass through the HEPA which can cause allergic reactions in people who breathe them

HEPA, PECO and your health

Various pollutants impact different people in different ways. It is important to choose an air filtration technology that works for you.Those who are allergic to mold are going to think about their air purification solutions differently than those who want to keep their children’s developing systems away from toxins that evaporate from household products.

There are as many ways to think about healthy air as there are people breathing, but to make it a little easier, consider three primary reasons your air might be making you sick.

  1. Infection – when a biological entity enters your body and replicates.
  2. Allergy – which results when we are exposed to chemicals called allergens that cause your body to initiate the overblown immune response called an allergic reaction.
  3. Toxic damage – which occurs from chemicals that outright kill your body’s cells or otherwise prevent them from working properly.

Next, we must consider the earthly sources that cause these problems:

Pollutants and their health impacts


Infection Allergy Toxic Damage














Inert particles***



*Also known as VOCs, ozone, and many others
**Pollen, dust mites, pet dander, scented products, etc.

***House dust, smoke, cooking oil, etc.


You will notice that several of the sources can be responsible for more than one reason. Almost all of them are too small to see, which is what makes figuring out what in the air makes you sick so complicated. For example, whole and intact mold spores could infect some people, but fragments of those same mold spores could activate allergies in others (or in the same people). Some people’s airways could be damaged by the chemicals evaporating from their paint, while someone else could be allergic to the scent chemicals in certain perfumes. Each substance that makes you sick is a different size, is delivered in the air via different physical methods and has different chemical properties.

Here is each of the sources of pollution and how each one typically floats around in the air:

  • Mold. Mold floats around in the air as spores and also as spore fragments, which are much smaller more easily inhaled into the lungs.
  • Bacteria. Bacteria occurs as individual cells or clumps of cells in the air, with a size depending on the species.
  • Viruses. Individual virus particles are very tiny, smaller than bacteria or mold but larger than chemical substances.
  • Gaseous Chemicals. At just a few nanometers (.0001 microns) individual chemical molecules are the smallest components of matter.
  • Allergens. These special chemicals sometimes float around on their own such as substances that evaporate as scents, and sometimes are stuck to the surface of biological particles like pollen, dust mites, or pet dander. Allergens stuck to the surface of biological particles can break up into very small sizes that still cause allergic reactions.
  • Inert particles. Particles of smoke, dust, or cooking oil can be almost any size, from large visible bits to individual molecules.

HEPA and Molekule’s filters versus contaminants

One key takeaway here is that almost all these sources, with perhaps the exception of bacteria, occur in forms that can be measured in fractions of a micron. While HEPA will effectively clear the air of large spores, pollen grains, and other particles, many of the sources of infection, allergy, and toxic damage are not stopped by HEPA filters because they apparently pass through the fibers than make up the HEPA media. However, the oxidation effect generated by Molekule’s PECO-Filter operates on any pollutants. The particles that cause allergic reactions are very small, and while HEPA filters can help to reduce suffering, they do not work in all cases to fully eliminate asthma and allergy symptoms. Molekule operates on a much smaller scale, and here is some of the research on the effect of the PECO technology on allergy symptoms.

Another takeaway is that HEPA is efficient to some extent at clearing large particles from the air. However, unlike what happens with a PECO-Filter, it is possible allergens, toxic chemicals or even infectious spores will become unstuck from the HEPA media and subsequently blow through the other side and back into your room. The chances of this happening are reduced if you change your HEPA filter on a regular basis. Though replacement HEPA filters vary greatly in price (anywhere from $25 to $200, depending on the brand and size) do not ignore the manufacturer suggestions on when they should be replaced. Also, avoid keeping dirty HEPA filters around, get them out of the building right away to help prevent pollutants from re-releasing back into the air.

The main difference between HEPA and PECO is that while HEPA filters trap pollutants on the filter media, Molekule PECO technology destroys pollutants. If you want to learn a little more about the pros and cons of HEPA filters and how they are rated, check out our blog on true HEPA filters. To learn more about PECO and how it works to destroy pollutants, check out our blog post on PECO versus VOCs, or read about PECO-Filters in our post about the benefits of changing your Molekule filters on time.

Written by