Abstract: Apparatus and methods for generating, administering, extracting and recovering sterilant gas for sterilizing and/or decontaminating enclosed spaces such as, for example, interior spaces of microbial isolators, and also to components associated with such apparatus and methods. Specifically contemplated herein, inter alia, is an arrangement for extracting gas, such as decontaminant gas, that includes a selectively removable arrangement for holding a predetermined quantity of a medium for interacting with gas, such as decontaminant gas, and promoting the recovery therefrom of at least one predetermined ingredient. Such arrangements may conceivably be utilized in contexts other than contexts of apparatus and methods for generating, administering, extracting and recovering sterilant gas for sterilizing and/or decontaminating enclosed spaces.