High-efficiency particulate arrestance (HEPA), also sometimes called high-efficiency particulate arresting or high-efficiency particulate air, is a type of air filter. Filters meeting the HEPA standard have many applications, including use in medical facilities, automobiles, aircraft and homes. The filter must satisfy certain standards of efficiency such as those set by the United States Department of Energy (DOE).
To qualify as HEPA by US government standards, an air filter must remove (from the air that passes through) 99.97% of particles that have a size of 0.3 µm. HEPA was commercialized in the 1950s, and the original term became a registered trademark and later a generic term for highly efficient filters.