The Permian Basin of West Texas and other oil-production regions are naturally saturated with hydrogen sulfide, a strong-smelling poisonous gas that forms underground as plants and organisms decay.

ExxonMobil reported a release of hydrogen sulfide gas Friday at its 634,400 b/d Beaumont, Texas, refinery, according to a company filing with the Texas Commission on Environmental Quality on Monday.

scavengers are specialized chemicals used to mitigate the presence of H2S gas in industries such as oil and gas production, refining, and wastewater treatment. These scavengers chemically react ...