Answers and Discussion: Hydrogen sulfide

1. C

2. B

3. A, B, C, E

Hydrogen sulfide is an extremely poisonous gas produced by microbial action on liquid manure under conditions lacking oxygen (usually a deep pit). Agitation of this liquid manure in a confined space will likely produce acute toxic effect. Hydrogen sulfide is an extreme irritant, which in high concentrations produces pulmonary edema as well as rapid unconsciousness and cessation of breathing. Only self-contained breathing respirators are safe to use in hydrogen sulfide situations.