Clearing the air about humidifiers

The Air-Conditioning and Refrigeration Institute (ARI) commissioned a study to determine whether indoor air humidifiers pose a health risk by passing bacteria and particulate matter into duct air. This was to clarify confusion that arose after the US Consumer Product Safety Commission issued a warning about the possible contamination from bacteria- and fungi-contaminated water reservoirs of room humidifiers. The ARI study showed that the health risk arises only from aerosolization from a reservoir as a means of humidification. Therefore, not all humidifiers pose a health risk since majority of indoor air humidifiers do not use aerosolization.