[5] Common names for hydrogen sulfide include hydrosulfuric acid (the product of it reacting with water), stink damp and sewer gas.

[6] H2S is also produced from the bacterial breakdown of animal and human wastes and organic materials in the absence of oxygen (anaerobic digestion).

Such sources include: natural gas/petroleum drilling and refining, wastewater treatment, coke ovens, tanneries and paper mills.

[7][8] During the agitation or mixing of swine manure in a deep pit storage system the concentration of hydrogen sulfide was observed in one study at levels exceeding 300 ppm inside the barn.

[8] In a study examining the concentration of hydrogen sulfide in a residential cohort during manure application, it was reported the levels never exceeded the Agency for Toxic Substances and Disease Registry acute exposure MRL of 70 ppb and only 14 readings at 1-minute intervals reported levels above the intermediate exposure MRL of 20 ppb.

[10] Symptoms of acute exposure include nausea, headaches, disturbed equilibrium, tremors, convulsions and skin and eye irritations.

[11] NIOSH also reports an IDLH or immediately dangerous to life and health, at 100 ppm, this is the level at which the effects of exposure would interfere with a person's ability to escape.