Not all air purifiers are created equal, and when considering which type of technology should go in your school, office, or small business, it’s important to consider what you’re trying to keep out. While talking about the difference between a 10 nanometer particle and a 300 nanometer particle may seem inconsequential, it can make a huge difference in the quality of the air you’re producing and ultimately breathing. 

Let’s Talk Particle Scale

When discussing nanometers, the particles are so small it can be hard to wrap your head around the difference in size. To further complicate this, some companies use microns vs. nanometers. For scale, 1000 nanometers = 1 micron (often seen as μm). Let’s review a few examples for scale… 

Mold Spores                10,000-30,000 nanometers 
Human hair                    5,000-200,000 nanometers 
Pet dander                      5,000-10,000 nanometers
Bacteria                         300-60,000 nanometers 
Asbestos                       700 nanometers 
Smoke (natural)            10-100 nanometers
SARS-CoV-2                  50-200 nanometers
Viruses                           5-300 nanometers 
Pesticides                      1 nanometer

There’s no doubt that if you’re looking for something to combat seasonal or pet-related allergies, or to keep larger mold out of the air in your facility, a less precise filter based on particle size will suffice. And while all these particles are pretty nasty, the further we get down this list, the more dangerous the particles get. In fact, ultrafine particles – or anything below 100 nanometers in diameter – are the most harmful and typically the most abundant type of air pollution. This includes viruses, such as the SARS-CoV-2 virus.

Limiting Exposure to Ultrafine Particles

Ultrafine particles are dispersed atmospherically in many settings. Examples are found in nature, from forest fires, ocean splashes, and viruses; combustion processes, from vehicular and power plant emissions and tobacco smoking; and synthetic sources, from toner pigment and many engineered products used for microtechnology. 

Portable air purifiers are a great solution to limited exposure to harmful particles, but not all operate at the same efficacy – especially when it comes to particles under 300 nanometers. 

HEPA Filter: HEPA is a type of pleated mechanical air filter. It is an acronym for "high efficiency particulate air” filter, as officially defined by the U.S. Department of Energy. This type of air filter can theoretically remove at least 99.97% of dust, pollen, mold, bacteria, and any airborne particles with a size of 0.3 microns or 300 nanometers. 

Ionic Filter: This genre of air purifier emits negatively charged ions that attach to floating pollutants, causing them to fall to the ground, effectively removing them from the air. 

Ultraviolet Light Purification: As the name suggests, these filters use UV light to destroy some airborne viruses and bacteria. They are often combined with other filter types and may generate ozone as a byproduct. Prolonged exposure to ozone can be harmful, though some manufacturers claim they are ozone-free. 

ULPA: ULPA stands for ultra-low particulate air (filter) and can remove at least 99.999% of any airborne particles of 100 nanometers in size. This is a more fine air filter classification than a HEPA filter, filtering particles three times smaller.

G200 Advanced Air Purifier: The Celios G200 three filter system allows the device to produce cleanroom quality air in small spaces – whether that be an office space, school, hotel room, dorm room, or restaurant. It can capture up to 99.99999% of particles and can filter materials down to 10 nanometers. That’s up to 3,000 times more effective than HEPA standards (and can capture particles up to 30 times smaller). It is also effective at capturing the SARS-CoV-2 virus (1).

As you can see by these metrics, HEPA filters or your traditional HVAC system likely isn’t enough. When considering an air purifier for your facility, take these limitations into account to ensure you’re doing everything you can to provide pure, clean air for those who work, visit, or stay in your space. 


(1) The Celios G200 Advanced Air Purifier meets the performance and labeling requirements provided in the U.S. Food and Drug Administration’s March 2020 Enforcement Policy for Sterilizers, Disinfectant Devices, and Air Purifiers During the Coronavirus Disease 2019 (COVID-19) Public Health Emergency, published March, 2020 (the Celios G200 Advanced Air Purifier has not been cleared by the FDA). Specifically, the Celios G200 Advanced Air Purifier has demonstrated up to 99.99999% filtration efficiency of ultrafine airborne particulate matter and is capable of filtering particles down to 10 nanometers in size. The Celios G200 Advanced Air Purifier has also demonstrated up to 99.99999% virus filtration efficiency of ΦX174, a small bacteriophage virus with a maximum diameter of ~32 nanometers.

The G200 Advanced Air Purifier is not intended to prevent or protect from any form of illness or disease (or otherwise). To reduce the risk of fire or electric shock, do not use this fan with any solid-state speed control device. Unplug or disconnect the appliance from the power supply before servicing. The appliance is only to be used with the power supply unit provided and it must only be supplied with voltage corresponding to the marking on the appliance. Do not operate any fan with a damaged cord or plug. Discard fan or return to an authorized service facility for examination and/or repair. Do not run cord under carpeting. Do not cover cord with throw rugs, runners or similar covers. Do not route cord under furniture or appliances. Arrange cord away from traffic areas and where it will not be tripped over. Do not allow children to operate the G200 Advanced Air Purifier or play near the G200 Advanced Air Purifier. Only plug the power cord into a standard electrical outlet. Do not use outdoors. Do not immerse the G200 Advanced Air Purifier in liquid and do not handle the G200 Advanced Air Purifier with wet hands. Do not insert a finger or foreign object into the airflow openings. Do not use the G200 Advanced Air Purifier in toxic or explosive environments or where flammable or combustible gases are present.

October 13, 2022 — Stephanie Giera