Hydrogen sulfide is a highly toxic gas that can be released from the breakdown of manure in pits, tanks, and storages. It is heavier than air and can settle into low spots and accumulate in confined spaces. High concentrations can also be released during manure agitation and pumping.
While hydrogen sulfide has a characteristic “rotten egg” smell at trace levels, at dangerous and fatal levels it has destroyed the sense of smell. Thus, odor cannot be used to warn of its presence! The following table, adapted from OSHA, shows health effects associated with hydrogen sulfide concentration.
