No observable effect level. The dosage of a pesticide in chronic toxicity studies that results in no discernible harm to experimental animals.
The dosage or exposure level at which no toxicologically significant adverse effect(s) can be detected. The NOEL has been used interchangeably with the NEL (no effect level). However, there is a distinction which is based on the interpretation of the occurrence of an effect. An NEL denotes that at a particular dose, there was absolutely no effect. In reality, an effect may have occurred but went undetected for a variety of reasons. Thus, the more accepted terminology is the NOEL, which indicates that while an effect was not observed under a particular set of test conditions, it does not preclude the possibility that some effect may have occurred.
No Observable Effect Level. The highest dose given which does not show an observable adverse effect to the organism.
In a toxicity study, the NOEL is the highest dose level of pesticide (consumed in the daily diet per unit of body weight) at which no adverse effect is observed. It is the dose level nearest to but less than the lowest dose producing observed indications of toxicity. It is also the level at which no significant differences exist between animals exposed to the pesticide and an unexposed control group. The study displaying the lowest NOEL is generally selected to establish the ADI.
No Observable Effect Level for reproductive harm (California Proposition 65)
no observed effect level. In a dose-response relationship, the NOEL is the highest concentration of a chemical that causes no observable effect in a group of organisms. [compare to threshold concentration/dose
NO OBSERVABLE EFFECT LEVEL. The level above which observable effects are believed to occur and below which no toxicity is observed.
(no observed effect level) a level of exposure to a chemical that produces no observable effect; usually it is used to consider adverse effects so NOAEL is "no observed adverse effect level."
The highest measured continuous concentration of an effluent or other toxicant that causes no observed effect on a test organism.
No Observable Effect Level; a level of exposure that causes no observable effect. Same as NOAEL.
see No Observed Effect Level
No Observed Effect Level. The maximum dose at which no signs of harm are observed.
No-observed-effect level; dose level at which no effects are noted.