Canisters are cleaned for reuse by evacuating and refilling with nitrogen or zero air multiple times to completely eliminate VOCs introduced during the previous sampling. After cleaning, canisters are left under vacuum in preparation for re-sampling. System pressure and vacuum readings control the evacuation and fill times to create consistent batch to batch cleaning. Silonite® coated manifolds and separate fill and evacuation flow paths ensure the most rapid elimination of VOCs and SVOCs possible.