Hydrogen sulfide (H₂S) is a colorless gas known for its distinct smell, often likened to rotten eggs. It is produced naturally during the decomposition of organic matter and can also be found in volcanic gases and natural gas. H₂S is highly toxic and can be harmful to humans and animals, even at low concentrations. In industrial settings, hydrogen sulfide is used in various processes, including the production of sulfuric acid and in petroleum refining. Safety measures are crucial when handling H₂S due to its potential health risks, which include respiratory issues and, in severe cases, loss of consciousness or death.