Hydrogen sulfide is a toxic gas with known deleterious health effects. Governmental units and industry have long-recognized the potential hazards that hydrogen sulfide presents to human health. The human nose can detect hydrogen sulfide concentrations at levels in the lower part per billion ranges. The annoyance threshold for hydrogen sulfide corresponds to various human health responses including nausea, vomiting, depression, diarrhea, and serves as an effective first-line warning system for potentially hazardous concentrations of hydrogen sulfide. Several governmental entities, including the state of Minnesota, employ ambient hydrogen sulfide air quality standards based on annoyance thresholds in an effort to regulate hydrogen sulfide in the ambient air and protect public health. A number of these ambient hydrogen sulfide standards have been criticized for their age and lack of documentation. Based on a review of the historical technical literature, the ability to quantify and determine the annoyance threshold for hydrogen sulfide has existed for approximately forty years. This paper provides an overview of the toxicity of hydrogen sulfide, the technical basis for the ambient hydrogen sulfide values currently used by the state of Minnesota, measurement methods currently available to measure hydrogen sulfide in the ambient air and a discussion of similar hydrogen sulfide air quality values from other governmental units.