Title: chronic
Long Title: IUPAC Gold Book - chronic
DOI: 10.1351/goldbook.16231
Status: current

Definition
Long-term (in relation to exposure or effect).

Notes
1) In experimental toxicology, chronic refers to mammalian studies lasting considerably more than 90 days or to studies occupying a large part of the lifetime of an organism.
2) In clinical medicine, long-established or long-lasting.

Source
- PAC, 2007, 79, 1583. 'Explanatory dictionary of key terms in toxicology (IUPAC Recommendations 2007)' on page 1595 (https://doi.org/10.1351/pac200779091583)

Other Outputs
- html: https://goldbook.iupac.org/terms/view/16231/html
- json: https://goldbook.iupac.org/terms/view/16231/json
- xml: https://goldbook.iupac.org/terms/view/16231/xml

Citation: Citation: 'chronic' 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.16231
License: 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.
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Disclaimer: 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.
Accessed: 2026-04-21T00:23:55+00:00