Abstract: A scheme for defining, inside a processing facility, a storage environment that is substantially free of a targeted molecular contaminant and in which one or more substrates are to be stored for a period of time before or after a substrate processing step; the scheme including: an air blower for providing a flow of air within a storage environment defined inside a processing facility; a substrate support for holding one or more substrates inside the storage environment; and a molecular air filter having an input face positioned to receive air from the blower and having an output face for providing a flow of filtered air inside the storage environment, the molecular air filter being constructed and arranged to remove an airborne molecular contaminant from air flowing into the storage environment to achieve a concentration level of the molecular contaminant inside the storage environment suitable for storing one or more substrates therein for a sit time corresponding to the time before a subsequent substrate pr