Hydrogen sulfide (H2S) is a colorless, poisonous, corrosive and flammable gas. It is produced naturally from the microbial breakdown of organic matter such as in sewers, and is often associated with the smell of "rotten eggs."
Although the odor of hydrogen sulfide gas can be detected in as small as 0.00047ppm, OSHA limits exposure to 10ppm over an 8-hour workday. At concentrations above 800ppm H2S is dangerous to humans.
GasLab offers hydrogen sulfide sensors useful in environments where exposure to H2S can be harmful.