A system for decontaminating a medical device includes a decontamination chamber configured to retain the medical device and a chemical dispersion assembly configured to deliver a decontaminating fluid to the decontamination chamber. A pressure control assembly is connected to the decontamination chamber and configured to control the pressure in the decontamination chamber. The system also includes a system controller configured to control the decontamination chamber, chemical dispersion assembly, and pressure control assembly. A pressure in the decontamination chamber is reduced to within a sub-atmospheric pressure range in a first evacuation step and add a decontaminating fluid into the decontamination chamber at a first rate while increasing the pressure in the decontamination chamber. Adding the decontaminating fluid increases a relative humidity in the decontamination chamber to a level that improves the efficacy of the decontaminating fluid.
