Indoor air quality is a major concern, especially for people with sensitive immune systems such as infants or the elderly. Particles like dust mites (and their feces), mold spores and other allergens in the air may trigger health symptoms such as allergies or asthma, and people search for a way to remove them from the air using filter media in a portable air purifier, special vacuum or HVAC system. One type of filter is a HEPA filter.

A HEPA filter in your HVAC system, air purifier or vacuum cleaner is designed to only filter particles (and not gaseous pollutants such as those in smoke) from the air in an effort to improve air quality. Limited studies have indicated that air purifiers with HEPA filters may help reduce the amount of particulates in the air to improve the overall air quality (Laumbach, Meng, & Kipen, 2015). However, many harmful pollutants, like airborne chemicals or particles in smoke, are much smaller than a HEPA filter can trap. There is also a possibility that given all the particulate matter (dust) that collects on a HEPA filter, it can provide the right conditions for mold growth. It was documented in a study in Korea that mold can grow on a HEPA filter (Kim et al., 2014) and potentially release back into the air.

The next artical will inftroduce if the HEPA filter can be washed.