July 11, 2020
The global spread of SARS-CoV-2 (the virus responsible for COVID-19) is challenging individuals to reevaluate how they keep their homes and businesses clean. This is especially true for dental professionals who risk exposure to contaminants, disease, and infections. Running air purifiers helps filter indoor pollutants and allergens, but can it help reduce the risk of introducing and transmitting the novel coronavirus?
How does the Covid-19 spread?
Understanding of how the novel coronavirus spreads is evolving. Current research shows the virus primarily travels short distances via respiratory droplets (coughing, sneezing, talking, etc). Thus the virus spreads mainly through person-person-to-person contact. This is why the best way to prevent the spread of the virus is to avoid crowds, maintain social distance, and wear a mask in cases where social distancing is not possible. Research also shows the virus can remain viable on certain surfaces for several hours and can spread through individuals touching a contaminated surface and then touching vulnerable orifices like the eyes, mouth, and nose. This is why regular hand washing and disinfecting surfaces are also advisable. Lastly, some growing research suggests the virus may linger in the air as an aerosol for up to three hours after emission and in some circumstances. So while an air purifier should not be the first line of defense, it could be beneficial as part of a plan to protect against the virus as long as they are properly installed, operated, and maintained.
What is an Air purifier?
Air purifiers are different from air filters and air cleaners. Air filters are found in heating and ventilation systems to collect dirt and debris. While they can reduce pollutants and allergens, the primary purpose is to prevent dust and dirt from clogging up the system. Air cleaners are more robust. They consist of a fan and a filter to specifically remove more particulates and allergens from the air than an air filter. And air purifiers are designed to remove even smaller particles in the air that often come from cooking, dust, fires, and emissions. These are the types of particles that irritate the lungs, trigger asthma, or produce allergic reactions. And some purifiers go as far as employing a certain process, like ultraviolet light sterilization or electrostatic filters, to kill or deactivate airborne toxins like mold, pathogens, viruses, and bacteria.
Are Air purifiers a good defense against the coronavirus?
Currently, there is not any direct evidence that filtration works to reduce transmission of the novel coronavirus. High-efficiency particulate air (HEPA) filters remain somewhat of an industry standard. HEPA filters are designed to clear out 99.7 percent of particulates. The droplets the virus initially travels in are larger and a size easily captured by HEPA filters, but the caveat is the larger particles must first travel to the filter. Conversely, the average coronavirus particle itself is 0.125 microns, which is smaller than the 0.3 micron limit. So as an aerosol, the smaller virus particle could potentially elude filtration.
There are other patented filter technologies including photoelectrochemical oxidation (PECO). According to the brand, these air purifiers use highly reactive atoms, or free radicals, to break down bacteria, viruses, and pollutants at the molecular level instead of filtering them out. While they do effectively rid the air of many pollutants without producing harmful byproducts, they do so at a slower rate than other air purifiers. Thus comparing the results of these different technologies does not provide the whole picture. And the National Advertising Review Board and Consumer Reports dispute some of the filtration claims regarding superiority to HEPA filters.
Air purifiers are especially useful for individuals with respiratory conditions who experience irritation from dust or allergens. And because some areas have enacted “self-isolation” or “shelter-in-place” orders, it is more important than ever to monitor indoor air quality for overall health and well-being. But in most circumstances, common air purifiers probably do not offer much protection against viruses and no air purifier can claim to trap or eliminate COVID-19 because it is simply too early to tell. However, air purifiers can still be worthwhile especially in dental offices, and both HEPA and PECO technologies are worth considering. In theory, if an air purifier mechanically removes pathogens and viruses from the air it reduces concentrations in the room. And the faster the air purifier cycles, the more chances there are of catching the virus particles and in turn reducing transmission.
Which Air purifiers work best?
Typically the best air purifiers include HEPA filters and are approved by the Association of Home Appliance Manufacturers (AHAM). In a dental office, these will capture drill aerosols, vapors, abrasion powder, and other contaminants. UV air purifiers can also mitigate contaminants and pathogens from things like saliva and blood as an extra layer of protection. Products rated by the AHAM have a clear air delivery rating (CADR) that measures speed and efficiency across the same metrics so consumers can compare products. Dental offices should look at products with higher CADR ratings. A few of today’s highest-rated products include:
10. IQAir Dental Pro
This specialized unit uses a triple filter system designed for the control of odors, VOCs, and contaminants specific to dental offices including aerosolized fluids, tissue, plasticizing agents, solvents, and mercury vapors. The model can work anywhere in the dental office and is easy to maintain with visible replacement indicators and filters that are easy to change.
9. AirSteril Purilizer PR-UV01
This is a ceiling mounted air purifier that will not take up any additional space by the unit. It draws air into the system constantly providing continual sterilization without operator handling. The AirSteril Advanced Photocatalytic Oxidation technology combined with UVC light kills up to 99.6 percent of pathogens in two hours.
8. Oransi Erik 650A
This model has a 12 inch deep MERV18 HEPA filter to remove 99.99 percent of particles, one of the highest levels of filtration on the market. It also has a propriety gas filter effective against odors, smoke, and other gases. Best for whole houses, facilities, or offices and can clean up to 1,560 square feet.
7. Surgically Clean Air Cascade White
This is a medical-grade air system designed to filter high volumes of air without air drag and higher noise levels. It uses multi-stage purifying technologies including HEPA-Rx, electronic cell, and germicidal UV bulbs to capture dust, volatile organic chemicals (VOCs), allergens, viruses, odors, and bio-aerosols.
6. Blueair Sense+
This model has built-in WiFi which enables performance monitoring and Alexa voice control. It also has HEPASilent™ technology, combining mechanical filtration with electrostatic technologies. It can deliver clean air with a whisper-silent operation.
5. Austin Air Healthmate Standard Air Purifier
This has a large cleaning capacity of 1500 square feet and has four filters including a large particle pre-filter for dust and dander, a medium filter for mold, a carbon filter for gases and chemicals, and a HEPA filter for small particles.
4. Dyson Pure Humidify and Cool
If you want a purifier with all the bells and whistles, this new model is a purifier, humidifier, and cooling fan all in one. It also has a sleep timer, nighttime mode, space heater, WiFi connection, and Alexa compatibility. It has a cleaning capacity of 400 square feet and is equipped with a HEPA filter.
3. Molekule Air
This is a new approach to air purification and is more expensive than other air purifiers. This model has a sleek design with two filters to capture and dismantle pollutants using PECO technology. It has a cleaning capacity of 600 square feet, again for smaller dental offices.
2. Honeywell True HEPA Air Purifier
This model is made for larger areas with a cleaning capacity of 465 square feet which may work in smaller offices. It is equipped with a HEPA filter and is AHAM approved. It has two filters and can circulate air up to five times an hour.
1. Alen BreatheSmart Classic
This 22-pound portable air purifier is primarily used for larger spaces but can cycle air quickly in a smaller room. It has a dirt sensor and filter indicator. It uses a HEPA/Ion filter.