HEPA is an acronym for “High Efficiency Particulate Arresting” filter. HEPA vacuum filters are the customary system used by the major vacuum cleaner manufacturers to eliminate allergens, dust, and mold from vacuum cleaner air exhaust. HEPA filters were invented at some stage in the WWII to filter out nuclear particles and dust in the course of nuclear weapons production and research. HEPA vacuums should have especially high efficiency filters that permit highest suction air current for cleaning effectiveness. If the HEPA vacuum is not correctly planned so that all of the air that goes into the vacuum is propelled out through the HEPA filter, allergens and dirt can discharge into the atmosphere.