Abstract: An air-cleaning cartridge for treating respiration air with a chemical as a packing, whose housing wall consists at least partially of an expandable, elastic material, is to be improved such that the size can be increased in a controlled manner prior to filling with the chemical, in order to achieve a reproducible contracting force of the expanded housing and in order to prolong the ready-to-use storage time of the cartridge. To achieve this, a pressure connection 7, through which a compressed gas can be introduced into the housing designed as a film bag 1, 1' in order to expand it to a predetermined volume, can be connected to one of the connections 2. The chemical 5 is filled from the filling chamber 3 into the pressurized, expanded film bag 1. After releasing the internal pressure into the atmosphere, the film bag tightly surrounds the packing introduced on all sides (Figure).