A decontamination procedure for a fuel cell power plant (10) includes operating the plant to produce electrical power for an operating period, and then terminating operation of the plant (10) for a decontamination period, and then, whenever optimal electrical production of a plant fuel cell (12) is reduced by at least 5% by contaminants adsorbed by fuel cell electrodes (24, 42), decontaminating the fuel cell (12) of the plant (10) during the decontamination period by oxidizing contaminants adsorbed by electrodes (24, 42) of the fuel cell. Oxidizing the contaminants may be accomplished by various steps including exposing the electrodes (24, 42) to flowing oxygen; to heated flowing oxygen; to a sequence of start-stop cycles; and, to varying controlled potentials.