Does Purifying the Air Help Disinfect Surfaces?

Does Purifying the Air Help Disinfect Surfaces?

air purifying

Everyone is searching for an effective and efficient way to provide a virus and bacteria-free work and transportation environment.  As such many schools, offices, and transportation fleets have installed air-purifying devices that claim will kill COVID-19 virus particles.  But are the claims valid?  Are these devices certified by the FDA or EPA?  Does using an air-purifying device eliminate the need for surface cleaning?  The answer to these questions is NO.

As reported by PBS News, Global Plasma Solutions (GBS) claimed a 99% viral reduction in the marketing of its air-purifying device.  However, those results are referred to as “shoebox results.”1  This means tests are conducted using chambers and do not replicate real-world conditions.  The reality is, air purifiers can trap and/or kill viruses and bacteria, but only the ones that are in the air at the time.  They cannot kill the viruses or bacteria found on a person’s skin (i.e., a person wipes their nose with their hand), or on a hard surface that that same person has touched.  Larger droplets emitted from a cough or sneeze will settle to the floor or table or chair rather than remain in the air.  Air purifiers cannot kill or trap particles that have settled out of the air.

How do air purifiers work?

  1. Air ionizers release negative ions into the air. They attach to tiny particles, giving them an electrical charge, which causes them to clump together and land on surfaces.  Once the particles have landed on a surface, they can be cleaned up.  Although there are studies that state the negative ions can stop the growth of bacteria, fungi, and viruses and inactivate them in the air, more studies need to be made to see if this is the case with COVID-19.  The major drawback with ionizers is that they produce ozone which is a lung irritant and can be harmful to humans, triggering asthma, throat irritation, and chest pains
  2. HEPA (high-efficiency particulate air) filters that are used in air purifiers, vacuum cleaners, and heating and cooling ventilation systems, trap contaminants and viruses. They are designed to trap or filter pollutants and contaminants that are transported in the air.  They are very effective, however; filters need to be changed or cleaned and any droplets or contaminants that settle on to surfaces will not be filtered.
  3. Ultraviolet (UV) light is a good sterilizer, and some air purifiers have a UV feature. However, a virus or bacteria must be exposed to UV light for several minutes to be destroyed.  The time-lapse involved makes this a less effective option for high-traffic areas.

The EPA supports the use of air cleaners and HVAC filters as they say they can help reduce airborne contaminants, but by themselves, air cleaning or filtration is not enough to protect people from COVID-19.2   Increasing ventilation (opening windows and doors and promoting cross ventilation) along with improving air filtration is part of a layered approach in fighting the spread of COVID-19, and this needs to be combined with physical distancing, frequent hand washing, surface disinfection, and mask-wearing.  Based on a study conducted by Colorado State University, “The air purifier marketplace is fraught with inadequate test standards, confusing terminology, and a lack of peer-reviewed studies of their effectiveness and safety. Unlike air filtration (where the air is pushed through a filter to remove airborne pollutants), there has been very little research on the effectiveness and side effects of “additive” air cleaning methods like ionizing devices.”3

A surface cleaner such as PURE® is EPA List N registered, so why aren’t ozone generators, UV lights, or air purifiers?   The answer is “These are examples of pesticide devices. A pesticide device is an instrument or other machine that is used to destroy, repel, trap, or mitigate any pests, including bacteria and viruses.  Unlike chemical pesticides, EPA does not routinely review the safety or efficacy of pesticide devices, and therefore cannot confirm whether, or under what circumstances, such products might be effective against SARS-CoV-2, the virus that causes COVID-19. Accordingly, List N only includes surface disinfectants registered by EPA and does not include devices.”

A multiprong approach is needed to stay ahead of illness-causing bacteria, fungi, and viruses.  Start by opening windows to let fresh air dilute indoor contaminants.  If that is not possible, HEPA air purification systems* combined with surface cleaning and CDC COVID-19 protocols will help create safer work and transportation environments.

*Research the technology and request test data from the vendor or manufacturer.






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