Anaerobic chambers and jars use palladium catalyst to remove oxygen by promoting the reaction of hydrogen and oxygen to produce water. The palladium catalyst can be inactivated by excess water and hydrogen sulfide. Routine reactivation is accomplished by heating the catalyst at 160°C for two hours. The catalyst can be tested for activity by flowing the anaerobic gas mixture containing 5% hydrogen over the catalyst in room air. If the catalyst produces heat, it is active. If the catalyst does not produce heat, it should be cleaned. Cleaning is accomplished by first heating the catalyst to 200°C and then flowing the Anaerobic Gas Mixture over the catalyst in room air while hot.