no observed adverse effect level (NOAEL)

https://doi.org/10.1351/goldbook.NT06911
Greatest concentration or amount found by experiment or observation, which causes no detectable adverse alteration of morphology, functional capacity, growth, development, or life span of the target organism under defined conditions.
Sources:
PAC, 1993, 65, 2003. 'Glossary for chemists of terms used in toxicology (IUPAC Recommendations 1993)' on page 2076 (https://doi.org/10.1351/pac199365092003)
PAC, 2001, 73, 993. 'Risk assessment for occupational exposure to chemicals. A review of current methodology (IUPAC Technical Report)' on page 1023 (https://doi.org/10.1351/pac200173060993)
This definition replaces an earlier definition of no-observed-adverse-effect-level (NOAEL).