What can happen to the sense of smell at high concentrations of hydrogen sulfide?

When hydrogen sulfide is present at high concentrations, the sense of smell can be significantly affected. At lower concentrations, a person may detect its characteristic rotten egg odor; however, with prolonged exposure or at very high levels, the nerves responsible for the sense of smell can become saturated or overstimulated. This overstimulation leads to a phenomenon known as olfactory fatigue, where the ability to smell the gas diminishes or is completely deadened. This can occur quickly, sometimes within just a few minutes of exposure.

As a result, individuals exposed to high concentrations may not realize they are in danger because they no longer smell the gas, which can lead to serious health risks or accidents. Understanding this effect emphasizes the importance of using appropriate safety measures and detection equipment in environments where hydrogen sulfide may be present.