Odour threshold

{
  "id": "MLC-T-CHM-008198",
  "term": "Odour threshold",
  "field": "Chemistry",
  "definition": "The minimum concentration of a substance in the air that can be detected by the human sense of smell. This value is determined experimentally by presenting a panel of human subjects with progressively diluted samples of a substance until a majority can no longer perceive its scent. The odour threshold for hydrogen sulfide (H2S), known for its rotten egg smell, is extremely low, ranging from 0.0005 to 0.3 parts per million (ppm).",
  "subject": "Chemistry and the Environment",
  "see_also": [
    "sulfides"
  ],
  "references": [
    "PAC, 1990, 62, 2167. 'Glossary of atmospheric chemistry terms (Recommendations 1990)' on page 2204 (https://doi.org/10.1351/pac199062112167)"
  ],
  "url": "https://mlchart.com/terminology/chemistry/odour-threshold/"
}