At present, most of the trace contaminants in spacecraft are controlled by adsorption on activated charcoal filters which, after saturation, have to be exchanged. For longer duration mission, a regenerative trace contaminant control could practically eliminate the need for resupply of adsorbents.This study investigated the possibility of using hydrophobic zeolite molecular sieves for regenerative trace contaminant control. In small scale laboratory tests, different types of pelleted zeolite samples have been exposed to a model atmosphere containing representative trace contaminants. Co-adsorption capacities have been determined and the effect of parameters such as pellet size and shape, humidity level and flow rate has been studied. On the basis of this study, a regenerative trace contaminant adsorber applying two different molecular sieves is proposed.