Lowest-observed-adverse-effect level

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The lowest-observed-adverse-effect level (LOAEL) is the lowest concentration or amount of a substance found by experiment or observation that causes an adverse alteration of morphology, function, capacity, growth, development, or lifespan of a target organism distinguished from normal organisms of the same species under defined conditions of exposure.[1] Federal agencies use set approval standards below this level.

The United States Environmental Protection Agency defines LOAEL as the 'lowest level of a chemical stressor evaluated in a toxicity test that shows harmful effects on a plant or animal. While LOAELs and LOAECs are similar, they are not interchangeable. A LOAEL refers to a dose of chemical that is ingested, while a LOAEC refers to direct exposure to a chemical (e.g., through gills or the skin).[2]

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  1. ^ "IUPAC glossary of terms used in toxicology - terms starting with L". Environmental Health and Toxicology Specialized Information Services. U.S. Department of Health & Human Services. Retrieved January 9, 2016. based upon Duffus, J. H.; Nordberg, M.; Templeton, D. M. (2007). "Glossary of terms used in toxicology, 2nd edition (IUPAC Recommendations 2007)". Pure and Applied Chemistry. 79 (7): 1153. doi:10.1351/pac200779071153.
  2. ^ Registries, EPA, OEI, SOR, System Of. "Terms & Acronyms".