An HEPA cartridge filter refers to an air filter unit using High Efficiency Particle Arrestance filter media (HEPA) capable of arresting 99.95% or higher of the sub-micrometre particles. They are cartridge taking the form of frames or panels mounted in a mono or multi-module housing.
In the case of the multi-module housing, the HEPA filters are usually preceded by a primary filter module designed to trap the majority of larger air-borne bust particles and/or a secondary filter module designed to trap finer dust particles passed by the primary filter. The HEPA frames and panels are usually disposable elements.