Title: time-independent test
Long Title: IUPAC Gold Book - time-independent test
DOI: 10.1351/goldbook.15096
Status: current

Definition
Acute toxicity test with no predetermined temporal endpoint.

Note
This type of test, sometimes referred to as a "threshold" or "incipient" lethality test, is allowed to continue until acute toxicity (mortality or a defined sublethal effect) has ceased or nearly ceased and the toxicity curve (median survival time vs. test material concentration) indicates a threshold or incipient concentration. With most test materials, this point is reached within \(\pu{7\!-\! 10 d}\), but it may not be reached within \(\pu{21 d}\). Practical or economic reasons may dictate that the test be stopped at this point and a test be designed for longer duration.

Source
- PAC, 2009, 81, 829. 'Glossary of terms used in ecotoxicology (IUPAC Recommendations 2009)' on page 955 (https://doi.org/10.1351/PAC-REC-08-07-09)

Other Outputs
- html: https://goldbook.iupac.org/terms/view/15096/html
- json: https://goldbook.iupac.org/terms/view/15096/json
- xml: https://goldbook.iupac.org/terms/view/15096/xml

Citation: Citation: 'time-independent test' 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.15096
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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: 2026-06-20T05:17:28+00:00