The present invention relates generally to an integrated system and method for humidity control and vapor-phase decontamination of laboratory equipment with a multi-component vapor, one component of which is water vapor. The laboratory equipment can be a sealable enclosure such as an incubator, isolator, glove box, clean room, fume hood, safety cabinet, or centrifuge. The carrier gas flow is preferably in a multiple-pass, closed-loop recirculating mode. The humidity control and decontamination can be carried out automatically without user intervention for an indefinite period of time once the system has been installed, the required utilities connected and the desired settings including temperature and humidity level programmed.The integrated humidity control and decontamination system can be retrofitted onto existing laboratory equipment.