HEPA filters were created in the 1940s and for the US Government to prevent the spread of airborne radioactive contaminants. It was commercialized later on, and the original term became a synonym for and a generic term. HEPA filters have evolved to satisfy the higher and higher demands for air quality in various high tech industries, such as pharmacy processing, hospitals, health care, nuclear fuels, nuclear power, and electronics.
Today, a HEPA filter rating is applicable to any highly efficient air filter that can attain the same filter efficiency performance standards as a minimum and is equivalent to the more recent NIOSH N100 rating for respirator filters. The United States Department of Energy has specific requirements for HEPA filters in DOE regulated applications. If a HEPA filter claims to be "HEPA-type", "HEPA-like", or "99% HEPA", they don't satisfy these requirements.
