A decontamination system useful for treating articles that have been exposed to nuclear, chemical or biological (NBC) agents may comprise a decontamination unit, a catalytic oxidation (CATOX) reactor connected to decontaminate off gases from the decontamination unit and a selector valve The selector valve may be configured to allow output gases from the CATOX reactor to pass to an exhaust during steady-state operation of the CATOX reactor and to allow said output gases to re-enter the CATOX reactor during warm-up of the CATOX reactor. Warm-up of the CATOX reactor may be quickly achieved as a result of recycling the output gases through the preheater during warm-up.
