Easily recognized by its rotten egg odor, hydrogen sulfide is responsible for most of the odor prob-lems associated with brewery and food pro-cessing wastewater treatment. Heavier than air, colorless, corrosive and extremely toxic, its pres-ence raises serious workplace health and safety concerns. This paper reviews the chemical treat-ment programs available to control H2S as well as some nonsulfide odors. These include organic scavengers that react with reduced sulfur com-pounds, neutralizers that eliminate an odor's objectionable characteristics, nitrates and inhibi-tors that prevent bacteria from producing sulfides, masking agents that replace one odor with another, and metal salts that remove sulfides as metallic precipitates. Biocides can control micro-organisms that produce odors, but chlorine is rarely used to eliminate H2S because of safety, handling and environmental problems. Case histo-ries describe the application of advanced prod-ucts that inhibit H2S production, and neutralizers that neutralize non- H2S odors.