14751 IUPAC Gold Book - incipient LC₅₀ 10.1351/goldbook.14751 14751 current 1 Concentration of a chemical which is lethal to \(\pu{50\%}\) of the test organisms as a result of exposure for periods long enough for acute lethal action to cease; in other words, the concentration below which \(\pu{50\%}\) of individuals will have a normal lifespan despite the previous exposure to a toxicant. PAC, 2009, 81, 829. 'Glossary of terms used in ecotoxicology (IUPAC Recommendations 2009)' on page 899 (https://doi.org/10.1351/PAC-REC-08-07-09) https://goldbook.iupac.org/terms/view/14751/html https://goldbook.iupac.org/terms/view/14751/json https://goldbook.iupac.org/terms/view/14751/plain Citation: 'incipient LC₅₀' in IUPAC Compendium of Chemical Terminology, 5th ed. International Union of Pure and Applied Chemistry; 2025. Online version 5.0.0, 2025. 10.1351/goldbook.14751 The IUPAC Gold Book is licensed under Creative Commons Attribution-ShareAlike CC BY-SA 4.0 International (https://creativecommons.org/licenses/by-sa/4.0/) for individual terms. If you are interested in licensing the Gold Book for commercial use, please contact the IUPAC Executive Director at executivedirector@iupac.org . The International Union of Pure and Applied Chemistry (IUPAC) is continuously reviewing and, where needed, updating terms in the Compendium of Chemical Terminology (the IUPAC Gold Book). Users of these terms are encouraged to include the version of a term with its use and to check regularly for updates to term definitions that you are using. 2026-06-20T01:21:32+00:00