NOAEL (No-Observed-Adverse-Effect Level)
At a glance: The highest tested dose at which no adverse effect is observed.
In toxicology, the NOAEL is the highest tested dose or concentration of a substance at which no biologically or statistically significant adverse effect is found in exposed test organisms. 30 Its counterpart is the LOAEL, the lowest dose at which a toxic or adverse effect is observed. 31 The NOAEL is a traditional choice of Point of Departure for risk assessment, although it is increasingly superseded by the Benchmark Dose.