Odor Complaint Form

Hydrogen Sulfide minimum risk levels The Agency for Toxic Substances and Disease Registry (ATSDR) has established minimal risk levels (MRLs) for exposure to hydrogen sulfide (H2S). The Minimum Risk Level represents an exposure level at which no adverse health effects are expected occur. The MRL exposure level is calculated assuming an individual is continuously exposed to a constant concentration of H2S for a defined period of time. The acute MRL value is for continuous exposure to H2S up to 14 days. The acute MRL for inhalation of H2S is 0.07 ppm. An intermediate MRL value is for continuous exposure to H2S from 15-364 days. The intermediate MRL is 0.02 ppm. Odor Threshold information The Odor Threshold for hydrogen sulfide can range from 0.0005 to 0.3 ppm. An odor threshold is the minimum concentration of a chemical substance in the air that a human can detect or recognize as a smell, measured in parts per million (ppm) or billion (ppb). It varies widely by chemical, with some like hydrogen sulfide having extremely low thresholds (detectable at parts per billion). There is considerable individual variability in the odor threshold for hydrogen sulfide in humans. Odor thresholds are heavily influenced by individual factors like age, smoking, and genetics, as well as test conditions like humidity.