Human Equivalent Concentration

{
  "id": "MLC-T-ENV-013525",
  "term": "Human Equivalent Concentration",
  "field": "Environment",
  "definition": "1. The human concentration (for inhalation exposure) or dose (for other routes of exposure) of an agent that is believed to induce the same magnitude of toxic effect as the experimental animal species concentration or dose. This adjustment may incorporate toxicokinetic information on the particular agent, if available, or use a default procedure, such as assuming that daily oral doses experienced for a lifetime are proportional to body weight raised to the 0.75 power.\n\n2. The human concentration (for inhalation exposure) of an agent that is believed to induce the same magnitude of toxic effect as the experimental animal species concentration or dose. This adjustment may incorporate toxicokinetic information on the particular agent, if available, or use a default procedure, such as assuming that daily oral doses experienced for a lifetime are proportional to body weight raised to the 0.75 power.\n\n3. Exposure concentration for humans that has been adjusted for dosimetric differences between experimental animal species and humans to be equivalent to the exposure concentration associated with observed effects in the experimental animal species. If occupational human exposures are used for extrapolation, the human equivalent concentration represents the equivalent human exposure concentration adjusted to a continuous basis.\n\n4. The human concentration (for inhalation exposure) of an agent that is believed to induce the same magnitude of toxic effect as the experimental animal species concentration. This adjustment may incorporate toxicokinetic information on the particular agent, if available, or use a default procedure. See A Review of the Reference Dose and Reference Concentration Processes (EPA, 2002).",
  "abbreviation": "HEC",
  "subject": "Health and safety",
  "references": [
    "Integrated Risk Information System (IRIS) Glossary",
    "EPA 2003",
    "RAIS 2004",
    "Health Effects Notebook Glossary"
  ],
  "url": "https://mlchart.com/terminology/environment/human-equivalent-concentration/"
}