This HND piece delves into that familiar "rotten egg smell" compound—hydrogen sulfide (H2S). We cover its toxic properties and regulatory status. It turns out that it's second only to carbon monoxide as the leading cause of fatal gas inhalation exposures in the workplace.
One of the reasons why this stuff is so deadly is that it inflicts olfactory paralysis upon those exposed (at a high enough concentration). Thus, you can smell hydrogen sulfide at low levels, where it is not so harmful. Once you get above a certain point, you cannot smell it at all. Then, it can kill you within seconds. Bad as it is, though, researchers are now talking seriously about therapeutic benefits of hydrogen sulfide.
Read the complete article.