Method and apparatus for the clean replacement of contaminated HEPA filters

A method and apparatus are provided for the replacement of contaminated HEPA filters without contamination of the surrounding environment. A filter housing is generally cylindrical and defines a filter receiving cavity. The filter housing having a filter receiving end and a filter removing end. An active HEPA filter is received within the filter housing cavity and is located near the filter removing end. A backup HEPA filter is received within the filter housing cavity and is located near the filter receiving end. A change-out bag is received within the filter housing cavity and is located adjacent to the filter removing end. The filter housing includes a gas flow path through the active HEPA filter without passing through the backup HEPA filter. For the replacement of contaminated HEPA filter, end covers are removed from the filter receiving end and the filter removing end of the filter housing and the change-out bag is opened. The backup HEPA filter is pushed into position of the active HEPA filter, thereby moving the active contaminated HEPA filter into the change-out bag during filter replacement. The change-out bag is sealed to isolate the HEPA filter for disposal.