The patented LO/PRO® multi-stage scrubber system is the most efficient and versatile chemical odor control system available. By promoting different chemical reactions in each stage, the LO/PRO system can target a range of compounds in a single scrubber system. The LO/PRO system an treat up to 24,500 cfm of odorous air in a single scrubber with very compact footprint. Higher airflows may be accommodated with special designs. Because of the low profile it may easily be installed indoors or outdoors and results in 99.5% removal of H2S.