Selig Zone Defense is a blend of petroleum and citrus terpene solvents that removes oil, grease, tar and soils from a range of surfaces. It contains no butyl or hazardous air pollutants, making it environmentally preferable compared to other solvents. The non-corrosive product is suited for use on motors, parts, electric boxes and controls, printing equipment and refrigeration and air conditioning equipment. Zone Defense emits a pleasant citrus fragrance that deodorizes as it cleans. It is approved for exterior degreasing of planes.