Do You Need an Air Purifier?

From record wildfires to COVID-19, rarely have we been as focused on the air we breathe as we have been in the past few years. A portable air purifier might be just what the lung doctor ordered.

Most models scrub the air via a highefficiency particulate air (HEPA) filter that removes at least 99.97 percent of airborne particles sized 0.3 micron or larger. This means that purifiers can capture pet dander, dust, pollen, mold, and air pollution that has entered from outside. Depending on the model, air purifiers with a HEPA filter may also capture bacterial and viral particles that are 0.3 micron or larger. Even though the COVID-19 virus is smaller than 0.3 micron, it floats in the air on respiratory droplets, which are larger.

When you’re shopping, pay attention to the clean air delivery rate (CADR). It tells you how quickly the filter will clean a room of a given size— the higher the number, the faster it works. To specifically remove gases and odors, the purifier should have an activated carbon filter.

Not everyone needs to buy an air purifier for everyday use, says Patricia Fabian, an indoor air quality expert and associate professor at Boston University’s School of Public Health. But she says the purifiers make sense for people with underlying respiratory conditions, such as asthma, as well as for pregnant women. Others who might benefit include people with seasonal allergies or allergies to pets or mold and people who live with smokers, near industrial areas, or near freeways. The Environmental Protection Agency suggests that people who live in areas at high risk for wildfires consider buying one.