Low relative humidity decontamination system

A method of decontaminating a device comprising dispersing a decontamination fluid as a vapor into a decontamination chamber containing a device to be decontaminated, the decontamination fluid containing peracetic acid and water; controlling a dispersion rate of the decontamination fluid such that the environment within the decontamination chamber is below 45% relative humidity throughout a decontamination cycle defined from when the device is placed in the decontamination chamber to when the device is removed from the decontamination chamber, wherein the decontamination cycle achieves a sterility assurance level of at least 10 to the minus three.