A vapor decontamination system for decontaminating a defined region. The
system is comprised of a chamber defining a region, and a generator for
generating vaporized hydrogen peroxide from a solution of hydrogen
peroxide and water. A closed loop circulating system is provided for
supplying the vaporized hydrogen peroxide to the region. A destroyer
within the closed loop circulating system breaks down the vaporized
hydrogen peroxide. A bypass conduit is provided to bypass the destroyer.
A controller causes vaporized hydrogen peroxide from the generator to
bypass the destroyer during a predetermined phase of operation.