No Observed Adverse Effect Level
Similar term(s): NOAEL, NOEL (no observed effect level).
The highest tested dose of a substance that has been reported to have no
harmful (adverse) health effects on people or animals.
Glossary of Terms
Can apply to a particular study, species (e.g. rat, dog), or all studies on a
particular substance. The difference between NOAEL and NOEL rests on the
definition of adverse effect only, that is, an experimental study that produced
a NOAEL will have stated the adverse effect to be observed before
Adverse health effect - Dose - LOAEL - Threshold (in an ecosystem)
Español: Nivel sin efecto adverso observable