Hydrogen sulfide (H2S) is a chemical compound with the formula H₂S. It is a colorless, flammable, and highly toxic gas with a characteristic foul odor of rotten eggs. Some common names for H2S include sewer gas, stink damp, and sour damp. The gas is produced as a result of the microbial breakdown of organic materials in the absence of oxygen.
H2S is used or produced in various industries, such as oil and gas refining, mining, tanning, pulp and paper processing, and rayon manufacturing. It can also occur naturally in sewers, manure pits, well water, oil and gas wells, and volcanoes. The gas is heavier than air, which means it can collect in low-lying and enclosed spaces, making work in confined spaces potentially very dangerous.
Exposure to H2S can cause irritation to the eyes and respiratory system, as well as apnea, coma, convulsions, dizziness, headache, weakness, irritability, insomnia, and stomach upset. In some cases, exposure to high levels of the gas can instantly deaden the sense of smell. H2S is one of the leading causes of workplace gas inhalation deaths in the United States.
