ABSTRACT ETHYLENE (C2H4) removal from an air sample by KMn04 was more efficient on a per volume of packing basis for three products using aluminum oxide (A1203) pellets as a carrier than for KMn04 crystals seeded on expanded glass cubes. High air temperature increased the efficiency of all carriers studied. High air humidity increased removal of C2H4 by KMn04 crystals on expanded glass but the resultant high moisture content of A1203 pellets decreased the removal of C2H4 by KMn04. Airstream flow was negatively related to C2H4 removal efficiency. Small expanded glass cubes increased overall surface area/volume ratios and increased C2H4 removal in comparison with large glass cubes. Alkalinity of the KMn04 dipping solution increased C2H4 removal when expanded glass was the carrier for KMn04. The highest C2H4 removal efficiency was obtained when the packing material was arranged in a tubular configuration.